text stringlengths 22 2.11M |
|---|
[Question]
[
My dragons have a... "difficult" personality.
They're very catlike. Sure, they're more like KrimsonRogue's cat (somewhere around chaotic good). But, if I want to make my dragons smug, blue-blood a-holes that you still want to cuddle, then I might as well give them the ability to purr very loudly.
Well, that actually would have one tangible advantage, if the dragon could use it to transmit data and instructions to the nanomachines in their body.
Problem is, dragons here are about as large as a draft horse, are filled with spongy and hollow structures on top of having air sacs to assist breathing, and I'm afraid that would ruin the acoustics.
Basically, there are two unique features to my dragons:
1. Air blubbers, a special type of aerogel, made out of fibrous, CNT-reinforced organic matter with densities around 200 kg/m^3.
These air blubbers are primarily located under the dragon's skin, serving as protection against blunt force trauma (like crash-landing).
2. Air sacs and hollow bones are present throughout the body, as dragons have a respiratory system similar to birds'.
There's also that large cats (lions, tigers, etc...) can't purr.
**So, how would dragons be able to purr very loudly?**
[Answer]
## How Cat Purrs Work:
Cats purr based on a set of muscles in their larynx:
[](https://i.stack.imgur.com/U7r7R.png)
## How Big Cats Roar:
As to how we can let a dragon roar loudly, we can look at how [big cats roar](https://www.livescience.com/16826-lions-roar-vocal-cords.html#:%7E:text=When%20just%20a%20small%20puff,translate%20to%20a%20big%20sound.):
>
> "What's peculiar about the lion and tiger vocal folds is that they
> have a very flat surface on the front," Titze said. "It's almost like
> two parallel plates."
>
>
> When just a small puff of air is blown between these two plates,
> vibrations start, Titze said. That's one key to the roar of a lion or
> tiger: They need very little lung pressure to make large vibrations,
> which translate to a big sound.
>
>
> The second secret to a big cat's roar is a layer of fat within the
> vocal folds, where other animals have a ligament. Fat is squishy,
> offering more leeway for the vocal cords to vibrate, Titze said.
>
>
>
## Dragon Rawrs:
Generally speaking, big cats that can roar cannot purr, while small cats that can purr cannot roar. However, seeing as dragons are biologically engineered, perhaps one way to achieve this is to use **two sets of vocal cords in series**.
One set, deepest in the throat, would generate the purring sound, using something similar to the cat's larynx. The other set, higher up, would be like a big cat's vocal cords, with two parallel folds and a layer of fat, allowing sounds to be amplified into roars.
Like this, the two sets of vocal cords would allow three modes of operation: dragon roar, dragon purr, dragon purr roar.
This would allow the dragon to intimidate foes using its roars, purr when it is enticed by dragon-nip, or purr-roar as a vibrational sound attack.
Cute but deadly!
[](https://i.stack.imgur.com/CKSbr.png)
] |
[Question]
[
I was recently inspired by a Netflix series into an idea for an alien biosphere, and I wanted some help with the finer details.
See the planet I have in mind has about twice the gravity and 6 times the atmosphere density of Earth. The main biome is a jungle filled with plants that grow taller then the higher gravity would allow through being held aloft by hydrogen-filled bladders like sea-based kelp forests on earth. And above those alien kelp forest fly whale like creatures that feed off airborne algae like baleen whales as well as hunters that feed on those feeding off the algae like killers whales.
I am a real sucker for sky whales and I wanted to see how big I could realistically make them with six times the air of earth to keep them airborne.
Now a couple of things, these are not biological blimps filled to the brim with hydrogen or helium, they still resemble whales with wings, which means that they cant be as ridiculously massive as the Blisterwing from Darwin IV with wingspan about 300 meters. But I still want them to be a little bigger than the Blue Moon sky whale that is only 12 meters. If it can't be bigger than the largest pteroterosaur, what is the point? Now what I want to know is this.
**What is the size cap for these flying alien creatures in their high gravity dense atmosphere environment? (In wingspan)**
[Answer]
**Swimming in the air**
I'd say there are two primary limitations, one biological and one physical.
The biological limitation would be whether the whale can get enough food in its natural habitat to sustain its size. This is largely up to you how much they eat and how much food is available. The other limitation is being able to fly.
There are two forces which can keep your skywhale afloat - lift and buoyancy.
**Lift** is dependent on *lift coefficient* - which is up to you and depends mainly on shape of the whale and more precisely its wings - *speed* of the whale and *area* of the airfoil - which in case of the whale would be primarily the wings, but also its underbelly - and *density* of the air. With assumption that you don't want your whale to fly at jet aircraft speeds and you don't want it to frantically flap its wings like a bird, it would be fair to treat it - in terms of generated lift - like a glider, which means it would benefit from having large, high-aspect wings (long and thin) as they have a better lift-to-drag ratio and with increased atmospheric density drag becomes a larger issue. There can also be certain natural phenomena on your planet which can increase the lift characteristics which can be utilised by your whales. Thermal soaring, for example is used by both birds and gliders.
It is probably fair to assume that your whale would be unable to support itself with lift alone, which where the other force comes in - **buoyancy**. It is worth noting that the comparisons to water animals such as actual whales are very accurate for your sky-whale, as we are operating on the same principle in the air - *density* is what is important.
The closest equivalent i can actually think of are ships. Ships are built of steel, which is denser than water, but float because they encompass a volume of air which is less dense than water. Your whale needs to employ a similar principle. At its extreme, you end up with a baloon full of hydrogen, but you can tone it down to whatever you feel is appropriate. There is a solution that is used by fish to regulate their buoyancy - swim bladder, which you could base your solution on. What you need to do is strike a balance, aiming for **neutral buoyancy**. Several things to note which will have impact here:
* The density of the whale's tissue - less is better. To achieve the largest possible whale decrease the mass (and hence the density), as much as you feel is reasonable. Reduce muscle density to a minimum. Reduce the bones - make them hollow or get rid of them and replace them with lighter structures. There is a bit of a limitation somewhere in there with regards to not letting the whale tissue collapse under its own weight or making it unable to breathe or circulate blood.
* Size of the "fly bladder" - bigger is better (in relation to the rest of the whale's body). Whatever you feel will not make it "too much" of a baloon
* Insides of the "fly bladder" - the less dense the gas filling the bladder is, the better. It could be hydrogen, it could be some unobtanium or handwavium. Less mass, more volume is better
* Atmoshperic density - larger atmoshperic density is acting in your favor, making it easier to achieve buoyancy. If it's not set in stone, you can try to adjust to achieve a bigger whale.
* Altitude - atmoshperic pressure will decrease with altitude which means its easier for your whale to fly at low altitudes
In summary, from a standpoint of flight there is no hard limit, but rather it is function of things mentioned above.
By striking a balance such that the whale can achieve a neutral or very slightly negative buoyancy you can make it so that it can use whatever lift force it has available to control its altitude, as well as things such as thermal soaring.
[Answer]
So, gas-filled for buoyancy but not quite just balloons.
2g, 6 Bar atmosphere...
It might be enough to forma biological balloon. For arguments' sake, lets take that so.
Given: A small creature can achieve buoyancy on this world.
Asked: What happens when we scale it up?
Answer: It would float *better*.
Because:
If we linearly scale up every single aspect of the creature, the relative buoyancy would remain the same.
However, we are scaling up a biological organism. One containing large gas-filled voids. Organs such as the brain, eyes, ears, reproductive organs, etc. *do not* need to scale up with the rest of the creature, thus improving mass fraction.
But what's the limit?
As you scale up the creature, the circulatory system would have to work harder.
Also, because it contains gas bladders, the tension on the skin of those bladders would increase, roughly linear increase per linear length increase. If the creature is twice as long (8x as heavy), its skin would need to withstand twice the tension to keep it together. Unfortunately one cannot indefinitely make the skin stronger just by making it thicker, eventually added thickness ads nothing to strength of a membrane.
So final answer: It depends on the natural toughness & durability of the creatures on this planet. **Being an Air Floater design does not prevent it from growing big, only the "normal" factors that would also affect its landborne relatives are applicable**.
And because it is supported by a more continuous support system of bladders, it can be *larger* than a land animal supported by legs.
(but still smaller than an ocean swimmer, where buoyancy imposes less stress on the body)
[Answer]
I am not an expert on biology, but I will try to answer as best as I can. So, double the effective weight and 6 times denser atmosphere. That effectively gives you a 12 times denser atmosphere overall, as the weight of the atmosphere will increase. But so does your creature. Honestly, there is no cap to the size of such a creature is only limited by the limits of your creature's metabolism-remember, insects became meters long when oxygen content was increased during the late Carboniferous and the early Permian eras. Since your creature effectively is a living hot air balloon, it should be easily able to grow bigger than the Blisterwing, the only forseeable reasons why it could not grow to that size would have to do with either external factors, or an inherent limit in the creature's biological processes which makes it so the creature cannot support itself when it grows too big. I would put your size cap around 350 meters or so. But again, I am not a biologist, so I may be wrong.
] |
[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 you've calculated the tidal heating of a moon in Watts using the method described in [How does one calculate the tidal heating of a satellite?](https://worldbuilding.stackexchange.com/questions/61059/how-does-one-calculate-the-tidal-heating-of-a-satellite?newreg=efa1b41d053d430793464601087ce542), how do you then convert this to surface temperature?
In my case, the moon orbits a gas giant which orbits a star.
[Answer]
**Equilibrium assumption.**
Once you have the heating power generated inside, $\dot E$, a reasonable way to calculate (or at least approximate) the surface temperature, is to simply assume that: all the power generated by the tidal heating, is radiated outwards and lost to space.
**Why assumption is reasonable.**
Note such assumption is indeed reasonable: assume the opposite: assume that the power generated is greater than radiated power, $\dot E > P$. This means that more heat is generated than the system is able to dump, meaning, an increase in temperature, meaning, $P$ will get larger because $P$ increases with $T$, and this will proceed until $P = \dot E$. Assume the opposite, assume $\dot E < P$, in this case, more power is being radiated outwards than being generated, meaning, temperature will decrease, and thus $P$ will decrease, until $P = \dot E$. Indeed, $P = \dot E$ is the *equilibrium* case.
**Calculating surface temperature.**
Using [Stefan-Boltzmann Law](https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law), the power radiated by a surface of temperature $T$ is:
$$
P = A\epsilon\sigma T^4
$$
where $A$ is the surface area of the object, $\epsilon$ is the emissivity of the object [for perfect blackbodies, $\epsilon=1$], $\sigma$ is a constant, known as Stefan–Boltzmann constant, and $T$ is the temperature *of the surface* (after all, power is being radiated outwards from the *surface*).
Since you claim you have $\dot E$, then just make said assumption above: $P = \dot E$. That said, temperature becomes trivial to find:
$$
T = \left(\frac{\dot E}{A\epsilon\sigma}\right)^{\frac{1}{4}}
$$
You might also want to include $P\_0$, the power radiated inwards towards the satellite [say, by a star, or whatever]. In such a case, the equation would be: $P - P\_0 = A\epsilon\sigma T^4$. The calculation of $P\_0$ is not complicated and can be done simply using geometrical reasoning.
**This is just an approximation:** A similar calculation than this is used to estimate temperature of planets, and to calculate Goldilocks zone (or habitable zones) around a star: the power received by the planet [Stefan-Boltzmann] + generated inside [tidal locking + etc] = power radiated outwards [Stefan-Boltzmann].
Above procedure is also used to calculate temperature of stars based on the radiated power [it is reasonable to assume stars are perfect blackbodies].
However, this calculation complete ignores absorption and re-emission of thermal radiation by atmospheric gasses [like, the greenhouse effect]. The more dense and atmosphere of a planet, the more this calculation risks being in error.
[Answer]
This article:
"Exomoon Habitability Constrained by Illumination and Tidal Heating", Rene Heller and Roy Barnes, *Astrobiology* 2013 - <https://arxiv.org/vc/arxiv/papers/1209/1209.5323v2.pdf> - has a lot info for anyone interested in the potential habitability of hypothetical giant exomoons orbiting giant exoplanets.
[Answer]
What you are looking for is called [heat equation](https://en.wikipedia.org/wiki/Heat_equation), and is a well established way to calculate the spatial and temporal variation of the temperature of an extended body knowing the energy flow.
$\partial u \over \partial t$$-a \nabla^2u=0$
In your case it can be assimilated to the case of [internal heat generation](https://en.wikipedia.org/wiki/Heat_equation#Internal_heat_generation).
$1 \over \alpha$$\partial u \over \partial t$$=($$\partial^2u \over {\partial x^2}$$+$$\partial^2u \over {\partial y^2}$$+$$\partial^2u \over {\partial z^2}$$)$$+ $$1\over k$$q$
where $\alpha$ is the thermal diffusivity $\alpha = $$k \over {c\_p \rho}$
By solving that equation after having assigned the boundary conditions you can get the temperature distribution in the entire body and thus also on its surface.
] |
[Question]
[
Assuming the person is durable enough to not break his hand, how fast would he have to move his fist to punch completely through a solid steel door that is 1 inch thick?
[Answer]
As clarified in the comments, the door is an ideal immovable door and we are to ignore that in a normal door the hinges or bolts which hold it closed will shear long before a big fat projectile like a human fist will punch a hole.
In this idealized case, we can compute an approximation of the necessary velocity of an non-deformable human fist backed up by the entire weight of the unbreakable unbendable human to punch through:
* The [shear strength](https://en.wikipedia.org/wiki/Shear_strength) of steel is about 350 to 1400 MPa (50,000 to 200,000 psi). Let's assume 1000 MPa. (To get an idea of how much this is, 1000 MPa is about 10,000 atmospheres.)
* To punch a neat hole, we must apply enough force to overcome the shear strength of the 25 mm of steel along the circumference of the hole; let's say that the circumference of the fist is about 400mm (it's a big fist but not huge).
* 400 mm circumference times 25 mm depth is 10,000 square mm, or 0.01 square meters.
* 0.01 square meters times 1000 megapascal is 10 meganewton. (For a rough idea of bigness, that's about 1000 tons-force.)
* 10 meganewton of force applied on a 100 kg body (big fist, big man) gives an acceleration of 100,000 meters per second squared.
* With a uniform acceleration $a$, a body will come to rest in a given space $S$ (= the thickness of the door in our case) when it starts with a velocity $v = \sqrt{2aS}$. Plugging in the numbers, we find that $v = \sqrt{2 \times 100,000 \times 0.025} = 71 \,\text{m/s}$. That's about 250 km/h or 155 mph.
] |
[Question]
[
I recently saw some new estimates about when Betelguese will go supernova and it got me thinking since a worldbuilding project I'm in the early stages of could plausibly see it happen given the timeline length I'm leaning towards. I've seen tons of estimates about general types of damage a supernova could do to a planet within a few dozen light years or so. I've also seen numbers suggesting that even supernova hundreds of light years away can be visible as a star even during full daylight.
So, question is this. How far away from Betelguese when at its peak supernova brightness would one need to be for it to look about as bright as our sun does from Earth? I've seen sources that say supernova give off about 1% of their energy in visible light, so I'm guessing this would actually still be pretty bad given the accompanying harsher stuff. Humanity could easily settle the space in this area by the time it happens and knowledge of its impending nature could influence colonization efforts, even if shielding a planet wouldn't be *that* hard to do.
[Answer]
Let's look at historical data.
[SN 1054](https://en.wikipedia.org/wiki/SN_1054) has an estimate of its distance from Earth at [6500 ± 1600 light years](https://en.wikipedia.org/wiki/Crab_Nebula). It was visible by day.
Then there is [SN 1006](https://en.wikipedia.org/wiki/SN_1006), which was bright enough to cast shadows! It happened about 7,200 light years away from us. Astronomers from the time estimated its brightness to be ¼ that of a full Moon:
>
> Egyptian astrologer and astronomer Ali ibn Ridwan, writing in a commentary on Ptolemy's Tetrabiblos, stated that the "spectacle was a large circular body, 2½ to 3 times as large as Venus. The sky was shining because of its light. The intensity of its light was a little more than a quarter that of Moon light" (or perhaps "than the light of the Moon when one-quarter illuminated").
>
>
>
[The sun is about 400,000x brighter than a full Moon](https://en.wikipedia.org/wiki/Apparent_magnitude#Example:_Sun_and_Moon), so... about 1,600,000 brighter than SN 1006's supernova.
[The apparent brightness of a light source is proportional to the inverse of the square root of its distance to the observer](https://www.atnf.csiro.au/outreach/education/senior/cosmicengine/stars_luminosity.html). To make a supernova like SN 1006's as bright as our sun, we need to bring it about 1,600,000½ closer to an observer on an Earth-like planet. That's about 1,265 closer, making it 5.7 light years away from the observer.
That would be... bad for the observer. Radiation follows the same inverse-square law as brightness. According to [XKCD What If no 73](https://what-if.xkcd.com/73/), a super nova blast from 1 AU away showers your retina with approximately a billion more times more energy than a nuclear fusion bomb pressed against your eyeball (just for comparison - I believe novas come from stars much larger than 1 AU so the scenario is unfeasible).
5.7 ly is about ~360,000 AU. So that would be like...
$$\frac{1}{360,000^{2}} = \frac{1}{129,600,000,000
}$$
Round down and it's a trillion times less radiation.
That means we reduce the radiation exposure to a trillionth of the 1 AU away supernova scenario. That's your retina getting 1/1,000th of the radiation of a fusion nuke blasting against it, which I believe most physicians would still consider unhealthy.
] |
[Question]
[
Assume an underground city existed below the surface of Antarctica. The ice sheet is ~2 miles thick on average. At what range/depth would the earth's thermal heat allow livable temperature for humans, assuming the civilization is technologically medieval (so no modern heating/cooling systems).
Note: "Livable" does not mean comfortable. Extreme hot or cold would be fine as long as humans can reasonably survive in it.
Please ignore the obvious issues with an underground city (such as lighting, respiration, excavation, food sources, etc) and focus solely on the temperature aspect.
I assume there would be little subterranean temperature change between the polar day and night (despite each being six-months long).
[Answer]
Not deep at all.
Assuming that "Livable" does not mean comfortable, people just have to hide from the elements to be able to survive. Indigenous people of Siberia and Alaska are surviving the temperatures plunging below -60°C. If you have shelter and fuel (and oxygen, of course) it doesn't matter how cold it is outside the shelter.
Venturing out into extreme cold is different, of course, and one can bundle up only so much. -80°C may not be livable for an extended period of time for a human, so if that is the requirement, we need to get warmer.
Within the Antarctic ice sheet, temperature gradient steadily rising towards the bottom, sometimes reaching ice melting point down below: [Revealing interior temperature of Antarctic ice sheet](https://www.esa.int/Applications/Observing_the_Earth/SMOS/Revealing_interior_temperature_of_Antarctic_ice_sheet). So getting 1000-2000 meters under the ice would definitely get people into livable, if not comfortable range.
But what if we want to get comfortable? In this case, we need to dig into Antarctic continent under the ice shield. [Geothermal gradient](https://en.wikipedia.org/wiki/Geothermal_gradient) suggests that for every 1 km of depth, temperature is rising by 25–30°C. To get the most comfortable +20°C, we need to get about 750-800 meters below the rocky surface under the ice.
] |
[Question]
[
In my world, one of my creatures is a 100kg, 2 meters long flying alien. It has a durable yet relatively light endoskeleton which allows it to have proper anchoring for its flight muscles and its overall appearance seems something between a bat and an [azhdarchid](https://en.m.wikipedia.org/wiki/Azhdarchidae) pterosaur. However, I'd like it to have a "backup plan", in which, should it undergo wounds that hindered it's mobility to the point it could no longer hunt, it'd undergo a "salvation process", essentially eating itself, following by a "second" creature bursting from its insides.
The "second" creature, very reminiscent in overall shape and abilities to an octopus, is in fact a survival strategy. These creatures begin their lives by leaving their chicken-sized eggs as Cephalod-like creatures, which then begin their efforts for survival. After reaching maturity and accumulating enough biomass (resulting in them becoming slightly larger than a [giant pacific octopus](https://www.nationalgeographic.com/animals/invertebrates/g/giant-pacific-octopus/)) , these creatures will essentially enter a "pupa" stage, in a process which will result into the body "shrinking" to a smaller size and creating a capsule around it, with this emergency body housing most vital organs and structures, such as the brain, lungs and digestive track. The "emergency body will have its excretion openings linked to the main body formed around it, as well as having linked blood vessels and nervous system (at this stage, the emergency body essentially acts as a second layer of protection to the main organs and lies in a dormant stage, with the main body truly housing only this emergency body, the necessary musculature, the skeleton and the reproductive structures, all naturally covered by a second layer of skin). Upon major damage to the main body, the "emergency body" will salvage as many nutrients as possible from the main body, sever these connections and burst out of it, starting over its cycle of growth and metamorphosis into its "adult" form. As an adult, the emergency body occupies most of the abdomen, where on earth would be the organs, and part of the skull. What I'm willing to achieve partially reminds me of of the [Krang](https://en.m.wikipedia.org/wiki/Krang), a fictional species of soft aliens which build themselves robotic bodies for protection and were a good example of what I'd like my creature to be.
Summing up, could a creature with such a life cycle and defense mechanism involving housing a body inside another possibly exist in any way?
[Answer]
## **LIVING POWER SUITS:**
So... Organic Daleks? I'd one-up this idea and say they are symbiotically living with a different species that's closely evolved with them, and that is relatively unintelligent but very responsive to influence. The 'pilot' organism is smart, and guides the breeding of the 'mecha' organism, or even several varieties, depending on the needs.
Your pilot species is developing mecha more than technology, it wouldn't even need to be a fully sentient species if you didn't want it to be (although it would be a good one). Losing a mecha would be like losing an old dog - traumatic, but survivable. And your pilot species could breed new mecha for each environment it encountered. Desert mecha, flying mecha, sea mecha, etc. The possibilities are endless and all biological.
If you want your species to become technological, genetics might come before metallurgy. You could justify cyber-mecha easily, and eventually even vacuum-resistant mecha suits with chemical oxygen reserves for travel in space. Your pilot species doesn't need to evolve to adapt to new environments, just make better mechas.
[Answer]
**Lizard tails**
Whether your idea is completely realistic I don't know, but I taste a fantastical element in there anyway. I would say it's possible, possibly with some evolutionary help to make it more plausible.
Lizards are already creatures leaving part of their tail behind if that tail is in danger. I'm assuming they instantly cut off all blood vessels and just scurry away.
For your creatures it would become much, much more complex. The problem is breathing and processing food. You have 2 choices.
*Separated indigestion and breathing* is the first thing on my mind. During development, the octopus part will grow the outer parts, until the 'external' lungs and digestion have been properly grown to take over breathing for the whole body. Possibly small versions of breathing and digestion will grow first, then growing in size to support the whole structure. The octopus will rely fully on the secondary system, storing enough air in the lungs and food in the liver/fat for the emergency cut and escape.
*Conjoined indigestion and breathing* might seem simple, as you might say it just grows from the original. Unfortunately it has some difficulties. The mouth and the breathing hole(s) grow to a certain size to accomodate for the right lungs and intestines. The creature might need to eat continuously small bites due to a small mouth, or have a too big mouth for it's size, making it a detriment. Same for breathing. And when you want to cut away, how do you separate the lungs and intestines? How will you close the wound you're making correctly?
Possibly you can start with conjoined intestines, growing larger for the full creature. When the body is large enough, you can seperate the parts, making the octopus again only connected with blood vessels, storing enough oxigen and such for the escape.
**Conclusion**
I would say it's unreasonable. The complexity is too high. There are creatures able to seperate body parts or go back to earlier phases (might add a link to it later), but this complexity might be a step too far without bioengineering. So unreasonable, but not unthinkable.
] |
[Question]
[
This question is inspired by the video essay series "Fantasy Re-Armed" by Shadiversity on YouTube, where Shad explores typical fantasy races and what weapons they and their opponents ought to use.
My lizard men have about the same body mass as a human and the same intelligence. Unlike many fiction lizard men, they walk with their spine horizontal, like most bipedal dinosaurs. Compare to a *Pachycephalosaurus*, but smaller.
Their teeth, claws, scales or feathers are not powerful enough to serve as weapons nor armour. Their tails are only moderately flexible, not prehensile. Their physical strength is comparable to a human.
One very significant aspect is their posture. Since they don't stand erect, they will be lower and longer than a man of the same mass. One disadvantage is that they cannot form as tight formations as humans since they take up more area. One advantage, however, is that when viewed from the front they are much smaller targets and potentially harder to hit - useful against melee weapons, crossbows and guns. On the other hand, they present a larger target from above, potentially making them more vulnerable to volleys of arrows.
I imagine that the tail provides useful balance that will make them better and faster runners than humans. (That's what tails are for, isn't it?) This might make them better skirmishers (armed with guns or bows and harrying the enemy) where humans make better formations.
Note that the lizard men will not necessarily always be fighting humans.
They can also ally with humans and form mixed armies to fight against other lizard men or other humans.
The technology is late medieval or renaissance. Guns exist, but they are only as powerful and reliable as 1500s arquebuses. There exists plate armour that is largely bulletproof, but it is expensive.
The lizard men have quite flexible shoulders and necks. They can, for example, lift a shield above their torso and pull their head back so it's above or behind the shoulders, if need be.
What weapons and tactics should they and their enemies use? What do I need to consider? Do you have any advice?
[Answer]
**Humans soldiers, lizard scouts**
Lizard men stand no chance in open combat. The way humans fight them is simple - engage them in a long drawn-out battle. In a one-on-one fight, perhaps, a trade-off of a lizard-man's faster speed and better sense of balance might win him the day. However, that comes at a cost which looses them the war, and that cost is *endurance*. Unique among pretty much almost every creature alive, humans are custom-built for endurance. We can outrun just about every living thing on the planet, given a large enough track (except for equestrians).
Humans will fight by drawing out battles as long as they possibly can - lining up early in the morning to force the lizard-men in kind and then using feints, charges, retreats, just about every move they can use, in order to artificially prolong combat. Not to mention that they'll choose to fight in horrible inhospitable times - such as the dead of winter or summer when lizards are shut down by the extreme temperature shifts. If the lizard men managed to control the battlefield, like say a swamp during fall, they would possess a significant home-field advantage - but that doesn't make up for the fact that everything else is a disadvantage. In short, lizard men are horrible soldiers.
They are, however, good scouts - they can outrun humans quite easily and their scales help make for natural camouflage. Not to mention that, as you point out, their small profile helps avoid arrow fire. They'd also be OK skirmishers as long as you were able to get them in and out of combat relatively quickly. So the lizard-men would have to ally with humans, or else avoid open combat entirely if they wanted to fight.
] |
[Question]
[
I want a creature capable of going from a solid structure capable of walking to a liquid or slimy substance clear as water or ocean blue.
How can this be accomplished?
[Answer]
# The mimic octopus
Octopi are highly flexible, satisfying the constraint of "fitting into any shape". One could easily imagine an octopus-like alien that walks in a more land-animal-like way. Perhaps this began as a way to travel from tidepool to tidepool in search of prey, with speed being necessary to avoid bird-like predators. Octopi already have flexible bodies and strong camouflage abilities, so one could imagine them developing the ability to ripple their skin and change its color in a water-like way, seeking protection from other predators too fast to avoid.
# Jellyfish with hydraulics
For something a little more exotic, we can consider the sea jelly / jellyfish. Sea jellies [can be almost transparent](https://www.montereybayaquarium.org/animals/animals-a-to-z/crystal-jelly) and are already close to liquid in their consistency. One can plausibly imagine the transparency being even greater. Thus, the challenge here isn't with being water-like, but with being able to walk.
The first problem that comes to mind is a lack of bones. While we could use a [muscular hydrostat](https://en.wikipedia.org/wiki/Muscular_hydrostat) like an octopus arm, the more muscles we add the harder the time we'll have keeping the creature liquid-like. Instead, let's consider something more like a [hydrostatic skeleton](https://en.wikipedia.org/wiki/Hydrostatic_skeleton): we can imagine long sacks that are extremely flexible when empty (think a plastic bag in the ocean) but become stiff when filled with water or air (think a party balloon). Using these sacks, the creature can form an internal semi-rigid structure when needed. We could imagine the creature using this to walk, either with muscles or by further inflation and deflation of these sacks, deflating a leg to take the weight off it, then inflating a sack behind it (in the "armpit") to push it forward, then inflating the leg again. The creature would still need some muscles to inflate the sacks, but this could be a single "lung" with plumbing throughout the body. When in liquid mode, the lung could be kept at the center.
The other big problem would be energy input. Sea jellies, as a rule, drift with the ocean currents, expending minimal energy and eating passively. You would need a mechanism for them to get all the energy needed for this walking. Hunting is a no-go: normal bones and muscles will be much more efficient and much faster. Instead, consider the creature feeding on small insects that land on it (perhaps attracted by it looking so water-like). Perhaps the creature walks into a relatively drier region, attracting more insects; after drying out over the course of the day, shrinking in size but having fed, it walks back to a water source and refreshes itself. This feeding mechanism would also go a long way toward explaining the evolutionary pressures that keep it looking water-like.
Finally, to explain the reason why it preserves the ability to become relatively liquid at will, rather than merely having an outer layer of jelly to attract insects, we can introduce some degree of predation. Since the way of walking is so slow, it relies on camouflage. The predators stamp their feet loudly to flush out prey, and they will see if something that otherwise looks water-like doesn't have ripples from the stamping. The best way to have ripples is to be a liquid. The creature will collapse into a puddle, and perhaps even push liquid water from inside to the surface to form an even better layer to show the ripples, re-absorbing it when the predator has moved on.
[Answer]
I think this could be possible if your creature was made up of multiple units capable of separating from a larger main body. For example, an individual ant behaves like a solid, but ants in a swarm behave like liquid crystals and [flow around obstacles](https://phys.org/news/2015-10-ants-solid-like-liquid-like.html). If you were to apply this to an individual organism, the units would need to be a lot smaller in order to act like a liquid, and linked together as some sort of colony or hivemind. The closest known organism to what you're describing would probably be a slime mold, where cells can contract and expand through chemical reactions.
[Answer]
# Not With Any Biology We Know Of
Nothing we know about biology supports a creature like the one you've described, so we're either talking about completely alien science and technology (and we all know the trope about "sufficiently advanced technology") or magic.
So, if we're assuming magic:
# A Self-Organizing Colony Creature
A bunch of small creatures, amoeba- or paramecium-sized, which (to hunt, perhaps, or to migrate when their water environment dries up) are capable of clumping together into a "creature" which walks over the land and dissolves into a cloud again when once again in water.
The evolutionary path to this creature is... unlikely, since a great many of the creatures would die in "land mode", but alien life can be "cool but implausible" if you wave your hands hard enough. (Energy and metabolism is *also* a problem.)
As an added bonus, it would presumably be somewhat difficult to kill, since you'd have to destroy most of its mass to kill the "land version" of the creature.
[Answer]
I don't think that a naturally occurring organism could transform itself from solid to liquid and back--unless you count animals that can survive being frozen solid and then thawed, which involves no water mimicry.
However, it might be possible to construct a robot that can impersonate a liquid.
Tiny robots, the size of grains of cornstarch, could move suspended within some medium such as water. If the flock of tiny robots could coordinate its own movements, what you would have is the equivalent of an animate blob that could flow like a liquid but sit like a solid--sort of like Ooblek. <https://www.scientificamerican.com/article/oobleck-bring-science-home/>
I'm not sure that water is the ideal medium, or what properties the liquid medium would have to have to construct the best robot of this type.
] |
[Question]
[
Postpartum depression among humans is a thing that is "normal" insofar as it happens a lot, but it is not "normal" in the sense of "a thing that we don't worry about"; it doesn't happen to absolutely everyone, and we do in fact put (varying amounts of) effort into educating people about it and treating women for it.
For a lot of creatures, however, the idea that you just give up and die after reproducing *is* entirely normal. Obviously, there are the examples where reproduction is necessarily mechanically fatal (like some adult insects which don't even bother having *mouths* because they won't live long enough to need to eat... and so *can't* live long after reproducing, because they *can't* eat), about which very little can be done, but there are also plenty of [semelparous](https://en.wikipedia.org/wiki/Semelparity_and_iteroparity) organisms that probably *could* survive indefinitely with appropriate hormone treatments and feeding, but which naturally just don't bother--like, for example, female octopuses which don't eat while tending their eggs for their entire gestation, and then lose the will to live and continue to starve to death after their eggs have hatched.
I know of several fictional depictions of semelparous aliens with mechanically-unavoidable maternal death (e.g., the alternate-universe aliens from Greg Egan's *Orthogonal* series and the Martians from Harry Turtledove's *A World of Difference*), and in both cases the development of medical technology to allow mothers to survive birth is treated as a major positive development for civilization (although with more realistic levels of conservative backlash in the former case)\*. I am not totally convinced that that is how it would always go, but I can accept it in an individual work insofar as the aliens are depicted as somehow *not* having a psychological makeup adapted to this mode of reproduction.
But suppose a species more like octopuses, with primarily psychological semelparity (i.e., the mother's body *can* still function, mechanistically speaking, but they uniformly just give up on life anyway), were to develop intelligence and civilization. Recognizing that there is likely to be intercultural variability across the species, does it seem plausible that they would at some point actually decide to try to treat "postpartum depression" and preserve life? And if so, how early in their technological development?
\*Side note: in real-world cases of semelparity, males tend to die as well, and earlier than females--male octopuses die after insemination, male salmon die after fertilization, and male spiders and preying mantises get straight-up eaten by their mates. Both of these fictional portrayals are a bit weird in that they present males as continuing caregivers after the mother's body is destroyed.
[Answer]
Like with any problem, we treat by looking at the cause. And the cause here is fairly simple - hormones. Not every mental problem is caused by hormones, of course, but such a radical shift in mindset after a physical event (childbirth) would have to be a result of a new hormone wave, or, alternatively, a hormone being removed. ([This paper](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3816400/) indicates it's a rise of a hormones, specifically stress hormones.)
Thus, to treat it requires hormone therapy. Hormonal imbalances, for the most part, can be treated with modern medicine, but that is *modern* medicine, i.e. stuff within the last 50 or so years when they started developing psychoactive drugs. That said, psychoactive drugs are as old as humanity (notable examples include alcohol, nicotine, caffeine, etc.), so while the full science behind it wouldn't be explained except with modern medicine, it's very possible that they'd be able to concoct an herbal remedy of various psychoactive drugs to help people past postpartum depression well before that. I can't tell you what exactly would work because you haven't given me an exact mechanism, but it's possible that this could be treated with natural drugs.
**WARNING:** I am *not* a doctor, and I am *not* a psychologist. I know a few things about science, but that doesn't qualify to diagnose anything in real life. If you are suffering from some form of depression, please don't walk away thinking that the correct way to treat it is with self-prescribed naturally occurring psychoactive agents, thank you. Talk to someone who is qualified, i.e. *not me*.
[Answer]
**This is a non-starter.**
Basically, there is no way for this kind of species to develop either real intelligence or civilisation or technology. (I get that octopusses are smart, clever, and intelligent individual beings.)
Some assumptions, based on the only species we know of that has evolved intelligence and has developped technology and civilisation.
1. Innovation & advanced technology & the ability to foresee, plan, and implement are not innate capabilities. In other words, no other species can build a toaster oven simply because there is some blueprint in its genetic code that allows it to build toaster ovens.
2. Culture, civilisation, knowledge, and technology (beyond the very simplest of tools) are additive in nature. In other words, without building up from zero, we can not have even arrived at the concept of "post-partum depression" (because we need the build-up of sense of self, what is health and illness in the physical, cognitive, spiritual, and mind-brain domains), to say nothing of an understanding of biochemistry, biology, chemistry and how these lead to the discovery and understanding of hormones.
3. The whole concept of cultural building is predicated on the fact that individuals within a species learn, experience, grow in learning & wisdom, and most importantly, pass that learning & wisdom on to others. If one individual learns how to make a copper axe, that's great! But if she can't pass that experience on to others of both her own cohort *and also to those who are younger*, the technological leap dies with her.
All that is to say that human culture & technological advance is possible because we have the ability to project our selves and our own experiences into the future.
The reason why a semelparous species like the octopus can neither develop a culture or a technology is because no individual can pass on its own experiences to the next generation. If you have an octopus in a tank that learns where you keep your supply of saltysnax, she can't pass that liking for your treats on to her offspring, because she dies as soon as they're born!
**Conclusion:**
Being unable to evolve useful intelligence and being unable to develop any kind of culture or technological capacity, there is just no way such a species can ever even conceive of the notion that there is even a problem!
] |
[Question]
[
A particular species of merfolk inhabit the abyss of the pacific ocean, they belonged to the secret clan which was tasked by the Atlantean emperor to seek immortality elixir. The emperor ordered their vocal cord to be removed as a punishment for not able to find the elixir and they are exiled into the abyss, without echolocation they must rely on vision which is similar to humans. I am wondering what can the merfolk use to lit up the abyss without invention of incandescent lightbulb, time period is early 14th century AD?
[Answer]
# Bioluminescent pets
Anglerfish come to mind.
There is evidence that giant squid are bioluminescent and that they use flashes to stun and catch prey. You may also consider for a really heavy metal factor, specially pirate metal. Suggested theme song: Leviathan, from Alestorm.
] |
[Question]
[
My fungus starts out as an extremely small spore, this small spore will bury and implant itself near the spinal cord and cerebellum, and will then secrete an enzyme that hijacks and later puts it in control of the brain. After getting use to the body of its new host, it’ll then slowly start to grow tiny mushroom that will poke out of the nape of the creatures neck which doesn’t cause any permanent harm to the body. The body will, after two months, produce an abnormal amount of mucus that is filled with many of the fungi spores. If the fungus controlled body bites another creature, then that creature will become infected with the fungus, which will slowly become controlled.
Once enough creatures are controlled by the fungus, then the creatures will begin to collect plants, leaves, dead bodies, and creatures, which will then be placed in a secure and safe location. Once this happens, the mushrooms on the napes of the creatures will spray out spores, which when these spores land on the biomass, they will begin a germination process. This process takes only 1 year to be completed. during half of that year, a mycelium network will be formed through the biomass, which will produce a chemical that assimilates said Biomass. Once the year is up however, the once randomly collected biomass of dead body’s, plants, leaves, and creatures will have been converted into a fungus colony, which is essentially a colony that consumes the environment around it, subsequently growing in mass and influence, but also produce a vast amount of spores.
If the colony doesn’t get harmed or destroyed , then an entire portion of an ecosystem can be converted, with many creatures either being consumed and used as biomass for the colony, or turned into walking fungus spreaders. To describe the fungus colony, an entire portion can look entirely different, trees will be covered in mycelium roots and fungi, the ground will have some hard patches but overall will be as mushy as dirt, any water will be quickly used up, but spread throughout the colony in equal amounts.
The colony however, doesn’t last forever, and every ten years that pass by, a winter like season will essentially kill off the colony, ridding that portion of the forest dead yet full of nutrients, which helps permeate the growth of new life. After the subsequent portion is fully restored, the fungus will begin anew
**could my fungus naturally exist, and if it can, how?**
[Answer]
# Complicated Cordyceps
Good enough for SciFi but I can't see it actually evolving.
Multiple spore based reproduction methods are unlikely, so the zombie bite spores and wind blown spore release in the same species of fungus would be troublesome in the real world.
Behaviour change on density of population is entirely reasonable, though the method of communication should be considered. How does a fungus know it's now in a high density environment. They would normally communicate via the [Mycorrhizal network](https://en.wikipedia.org/wiki/Mycorrhizal_network).
The urge to gather food is reasonable if that's the food the species normally gathers, however most insect species gather food as fast as they can anyway, already without much consideration for the survival of the individual. Only the colony matters, so this aspect is redundant. However you haven't stated what species you intend this fungus to affect, cordyceps normally only affects insects.
**Apart from the fungal infection, you've described [army ants](https://en.wikipedia.org/wiki/Army_ant), and for those purposes your fungus may as well be a surface yeast infection with no effect on the insects themselves.** If you're asking for it to affect say, sheep, then you'll hit a barrier, mammals haven't been shown to be vulnerable to the likes of cordyceps, though things like rabies and others do significantly adversely affect behaviour.
] |
[Question]
[
My friend and I are working on a map of a globe. The setting of this universe involve various intelligent animal species divided into 5 clades: Archo (Crocodilians), Avians (Birds), Aquatics (Fish), Eutherian (Mammals) and Saurians (Lizards).
Each clade is suited to a different environment.
The images below were produced by overlaying different black-and-white images of landmasses. The BW images are produced using a random terrain generator.
You can see the image projected on a globe here: <https://www.maptoglobe.com/HyOmcSuz8>
As a general description world: The world is composed of many islands, archipelagos, gulfs and isthmus. It is divided into three continents. Lets call them Left, Middle and Right.
The Left continent has regions of tropical forests, deserts and tundras. The desert is divided into three sections by mountains. There is a long river running through the desert.
The Middle is tropical and it is contains many island chains.
The Right is also mainly forest but there are section where it touches the North Pole.
[](https://i.stack.imgur.com/5klh0.png)
This is the flow of sea current. The orange arrows are warm water, blue arrows are cool water, and the green arrows are average temperature. White arrows show the direction of current.
The land areas that are spray painted red are warm humid coasts with corals. Blue is stiller water with fishing. Purple is El nino hotspots.
<https://i.stack.imgur.com/h8GnY.jpg>
This the tectonic plate map. The arrows show the direction of movement of the plates and the colours indicate a trench (violet) or a mountain (red)
<https://i.stack.imgur.com/SLqnO.jpg>
Currently the maps *appears* fine to us for the most part. However we want a second opinion of someone(s) more experienced. The issues that I have right now is the edges seem quite jagged and I'm not sure if that is possible at that scale.
The continents also have many cracks and holes in them. Is this possible? And if so, what are the criteria for them to occur?
Finally, is the map accurate? Given the ocean currents and tectonic plate positions, is it possible to create these landmasses depicted on the map?
**EDIT:**
Thanks for all the advice. These are the updated maps. Decided to use the Aitoff projection because it gives a better sense of the area.
[](https://i.stack.imgur.com/5JEyl.png)
[](https://i.stack.imgur.com/Fudj9.png)
We're still open to any suggestions on the world as well as any advice on the map-making process.
[Answer]
(Note: since it isn't otherwise specified, I'm assuming that the planet is overall fairly Earthlike. Similar axial tilt, seasons, day length, temperature range, etc. If it's not, a lot of this goes out the window.)
## Left Continent
Overall, this continent has a strong South America feel, with a bit of a twist. South America has the Andes along its west coast, caused by the Pacific plate subducting under the South American plate. Instead, you have three plates all crashing into one another in the center of this continent. That's going to result in a Himalaya-style plateau instead. Unless you have a giant volcano hiding somewhere, your world's highest mountains are going to be in that range. To the eastern side of that, you have a warm-water coast with an onshore current on the equator, which definitely reminds me of the Amazon-basin. So that deep gray cut into the center of the continent would be an outflowing river, rather than an oceanic inlet. On the western side, you have a cool current in the rain shadow of a giant mountain range, which is going to give you extremely dry deserts like the Atacama in Chile. The north is going to be a hot, dry desert, much like Northern Africa.
In the south, that large sea is likely to give that part of the continent a very Mediterranean feel; the whole area's likely to be something like an inverted Europe. I'll note that you have a "warm" coastline marked at about 60\*S latitude, which is about the level of Norway or southernmost Greenland. So "warm" is going to be somewhat relative, unless your world has a much steeper axial tilt than I'm expecting. The "warm" area right above that is about the level of Spain, but it's climate is probably going to be closer to the Pacific Northwest.
## Middle Continent
To be honest, geographically speaking, this continent/archipelago is a bit unusual. What I can think of is that the whole continent is relatively flat and very low-lying, so the seas between the islands are quite shallow. Very wet and tropical throughout, much like Southeast Asia. The northern coast isn't going to be "cool", though. 25\*N is the same latitude as the Gulf of Mexico. You're going to see hurricanes forming along that coast in the summer and fall, although they're mostly going to swing north away from the continent and into open water. The southeast of that continent will definitely get smacked with hurricanes, though, spinning up in the ocean south of Right. And if the terrain is flat overall like I'm thinking, they're going to go all the way across, regaining power over the extremely warm inner seas.
I must say that I disagree a bit with how you have the plates moving in the ocean to the north. You have three plates coming together, which should be enough to form more than a relatively small island chain. To me, that looks more like a mid-ocean rift, with the two northern plates moving away from one another and islands along the border being highly volcanic. Basically, they're like Iceland, although the climate is going to be more along the lines of New Zealand.
## Right Continent
The feel I'm getting from this continent is basically North America with Southeast Asia in place of Mexico. The northern part of this continent is going to be much like Canada or Russia, with boreal forests fading into tundra as you move further north to the pole. The warm spot on the west coast I'd expect to be somewhat like northern France. My initial thought was the US Pacific Northwest, but without a mountain range like the Rockies keeping the moisture on the coast, you won't get the same sort of temperate rainforest. On the other hand, if you reverse the tectonic direction in the ocean to the east, you could put another plate division on the coast and then you *would* have a coastal mountain range.
The southwest "cool" would probably be much like southern California, actually. The purple southern coast would definitely be tropical, with the large island to the east in roughly the same position as the Philippines. The blue area above it is going to be a lot like Japan if there's any sort of mountainous terrain there.
Tectonically, you don't typically see plates going from ocean to continent to ocean like the northern one does; one coast or the other probably needs a faultline along it. As I mentioned above, my vote's on the west coast. You'll also have a rift valley splitting the continent east-west where the southeast plate is moving away from the northern one, and the southeast is going to see volcanic and earthquake activity where that small plate gets pushed north by the southwest plate sliding past.
[Answer]
It looks really good! I love how much thought was put into the thermal currents, and the direction of plate movement which (I assume) will directly impact the sort of terrain that can be found where these plates meet and contest one another. Looks like there will be lots of mountains. Also, you can absolutely have numerous lakes and large depressed areas in large continents. That causes no problem. The Aral and Caspian Seas and numerous other decent-sized inland lakes and seas exist in Asia, so I don't see why your world's water system wouldn't be similar. Only one thing - it appears you have some warm, humid coastlines at fairly extreme latitudes. If this is a globular planet, would you expect to find those sorts of climates so close to the presumably arctic regions?
[Answer]
My world building project creates a 6000x2800 "image" that is used to map the elements on. Each pixel is a 4x4 km area. The jagged edges of the continents is done at this 4x4 km granularity... your map is fine in this regard. Only you know how much detail you are planning on zooming to for the rest of your design. Depending on how much of your map you will be adding details to like this, you will have a major bit of mapping work to do.
Your ocean current diagram seems off to me. Ocean currents traverse warm zones to cold zones, thus the warm will push north or south and then flow in the reverse once it cools off. The spin of the planet also contributes to this flow, think of how a toilet water spins differently in the northern and southern hemispheres. This means your currents will swirl the same directions in each hemisphere, anchored along your equator. Notice the hot and cold sides of circulation on this diagram of the Earth. Also notice the equator currents flow mostly like the Earth is spinning under the water, thus they flow west to east. [](https://i.stack.imgur.com/tr06B.png)
Air currents do similar things. Think of the air layer as loose fitting with the world trying to spin under it, so the features of land and open ocean create turbulence at a global scale. Evaporation, rain etc. all combine to create weather.
Tectonic plates are important if you want to identify volcanic and earthquake zones. Most of the "movement" is so slow it doesn't come into play in a normal campaign or world story. If you are dealing with this kind of timeline, then the movement of these plates might be important for other purposes.
[Answer]
The jagged edges could be explained if your world went trough some extreme glacial eras (with the ice reaching the equator).
One thing I notice is that the sea area is small in proportion to the land area. This would imply a land with a lot of mountains because al the plates of emerged land would be bumping and rubbing against each other. So this could explain the rough landscape.
But in this world you would miss the remote place with the mysterious people isolated from the rest of the population.
] |
[Question]
[
In the movie *Primer (2004)*, there are two main characters who travel back 24 hours in time using their time machine. When they arrive, both they and their past selves exist in this same town at the same time. Unbenownst to them however, one of the characters named Aaron has forgotten that he had his cell phone in his pocket when using the time machine. Both his cell phone and its molecular duplicate in the alternate Aaron's possession exist at the same time; likely both being in relatively similar vicinities (same town, less than ~20 miles apart).
After arriving back in the past, Aaron receives a phone call from his wife. Before time traveling, Aaron received this phone call previously while we was inside of a nearby hotel. However now he is receiving the call while outside, possibly implying that his double who is inside the hotel did not receive the phone call.
Both characters panic and discuss the ramifcations of what just happened. They are unsure of how cell towers work when it comes to having two identical receivers (phones).
In reality, what would/could happen in that situation? If you were to clone a cell phone, would both people holding the cell phone receive a ring? Would both people be able to pick up and speak? If one person picks up, does the ringing stop for the other? Does it depend on where both people are located (ex. closer person to the tower)? Is it possible to simulate this in real life (ex. duplicating the SIM card)? Why or why not and how, for any/all of those questions?
[Answer]
*Disclaimer: I'm not a cellular network engineer, nor was I in 2004. I have a rudimentary knowledge of network design, and enough knowledge of programming to be dangerous.*
Now, let's make some assumptions:
1. I'm going to call the wife's phone 'sender' and her cell tower 'tower 1'
2. The original phone is 'receiver 1' and the clone is 'receiver 2.' They're both connected to tower 2, and receiver 2 is closer to the point of origin.
3. Receivers 1 and 2 have the same hardware and software information.
I'm going to discuss protocol from the networking side. Basically, cellular networks work by keeping track of the phones in a specific tower's area and handing over control when they leave the area. That's why it's *cellular*, because there's 'cells' of influence.
Now, you're a cell tower and receiver 2 enters your sphere of influence. What do you do?
Well, since receiver 1 is listed already, fraud protection might kick in, as @AlexP said. The two devices have identical IMEI and SIM information, but different location signatures after all. Somewhat. While your cell tower can determine your approximate location through analysis of the signal's direction and strength, the technology isn't all that accurate. I don't know if it was even extant in 2004, but I suspect it was, this being after the events of September 2001. If the two devices are close enough, the discrepancy could simply be ignored as signal noise.
If we assume that fraud protection doesn't kick in, and that the two phones stay close enough together for the cell tower to be unable to determine that they're different devices, then what happens when the call comes in?
First, the tower would send the receivers a network packet telling them they've got a call. At some point, the receivers need to respond. I don't know the true internals of the 2004 era cell network, but I assume that they handshake immediately. The cell tower receives two ACK messages. Now the cell tower needs to act on this. It can act in one of two ways: Either ignore the second ACK packet, or clue in to the fact that there's a phony phone and boot them both off the network until the situation can be figured out by a human employee.
I'm going to assume the former. The cell tower, having received confirmation, may or may not reply to the receivers with another ACK, then tells the sender that they've connected. The sender will begin hearing the beep beep beep of the waiting noise.
Now receiver 2 picks up the phone. A 'ready to connect' packet gets sent to the cell tower. The cell tower either handshakes it, or simply begins the call connection. In either case, I'd imagine that receiver 1 is left ringing, as it has not been told that the call has been canceled and has not prepared itself to receive the call.
[Answer]
A plothole. Those are not the same phones, those are not the same numbers, those are not the same people. One is 24 hours older. Same with the phone. They share similarities but one of them have integral clock that is 24 hours in the future. And not by setting the time forward. The amount of 0 and 1's to make program change it's date have passsed.
The phone "of the future" just don't log into the system. This is somewhat similar to "2k bug". The problem was that the date fill eff programs, bios, systems up. And everyone panicked and no one really even considered "Hey, let's just set the date to 1972 and use just some overhaul to show 2000 and in the meantime try to fix the problem".
] |
[Question]
[
[](https://i.stack.imgur.com/Aheue.jpg)
(Sorry if my English is weird or my formatting. I'm not used to Stack.)
Anyway, I'm not sure how to summarize the two cases in my mind without the images, but case one is a 3-star system and a planet orbiting two of them at a time (inner orbit) in a corkscrew way, bouncing one from the other. Case two would be a more traditional orbit, with a less traditional "eight" one of the planet being constantly transferred away from one body to another.
Would any of these systems be possible or better, stable? Would there be any habitable zone in either case?. I apologize for my lack of knowledge in the topic and how broad and hard to answer it may be, but thanks in advance
[Answer]
## Probably not
A similar question, [Can a planet have a figure-8 type of orbit around two separate stars?](https://worldbuilding.stackexchange.com/questions/2726/can-a-planet-have-a-figure-8-type-of-orbit-around-two-separate-stars), addresses 8-shaped orbits around binary systems, instead of embedded within triple systems. In that question, it was revealed that a non-elliptical orbit can exist between two stars, but it isn't stable. Presumably, life couldn't develop in a two-star "8-orbit" system before the planet was kicked out. This makes your diagram on the right difficult to explain.
A three-star system like the one on the left wouldn't be stable even without planets. The stars will want to orbit the system's barycenter in an ellipse, so the gravitational forces that can distort their elliptical orbits into a figure-8 will probably kick out a star or two given enough time. Plus, it would be difficult for an 8-shaped triple system to form from a spinning disk. It would be even harder for a binary to capture a passing star into a stable orbit. Such a system would not form, and would not be stable in the long term.
## Alternatives
[There are many](https://www.quora.com/Is-it-possible-for-a-planet-to-orbit-three-suns-like-in-Dark-Crystal) stable three-star system configurations in which all orbits are elliptical - and they could conceivably support habitable zones given enough distance between the stars. The closest star to our sun hosts [at least one exoplanet](https://www.space.com/proxima-centuri-candidate-alien-planet-proxima-c.html) in the habitable zone of such a triple-star system.
] |
[Question]
[
So, I have been a bit disappointed with the answers on how to store **degenerate matter** from my previous thread, and now I'm even wondering whether one can produce it at all, without invoking unrealistic femtotechnology.
As everyone knows, to even convert regular matter into degenerate matter, requires insane amounts of pressure. Unfortunately, regular materials would certainly break after a certain amount of pressure, and the highest pressure generated in laboratory conditions is only 770 GPa (from a diamond anvil).
I came across this forum full of nuclear physicists, who realise that to make successful nuclear reactions which actually generate energy, they need **electron degenerate matter**, which can be used to emulate a Type Ia Supernova.
>
> I understand well that protons fuse very very slowly (and don't get much faster either with greater compression or with CNO cycle), which means that ordinary stars can last for billions of years but that a fusion reactor using only common isotopes of hydrogen sounds difficult to achieve useful power outputs from unless it was the size of a small stellar core, even if we had Dr. Minkovsky helping us out with containment.
>
>
> However, I also understand that in a type Ia supernova, "cold" gas is compressed so tightly that it becomes electron-degenerate, and that if enough additional gas is added, a portion of it eventually "flashes" to fusion very rapidly, forming a spectacular and rapid explosion. The power density is on the very, very, very rough order of 10E13 times that of the sun.
>
>
> <https://fusor.net/board/viewtopic.php?t=11536>
>
>
>
[](https://i.stack.imgur.com/caJBZ.gif)
As shown here, the compression required is around 1 ton per square centimeter, not as bad as say, neutronium or quark matter. If we have theoretical strong and utterly fireproof materials (i.e. AB-Matter, Starlite, Muonic Metals, Monopolium; only slightly unobtainium; the last two are also REAL DENSE) for the compressing machine, could electron degenerate matter be created with enough pressure?
If not, then is there any possible method of generating electron degenerate matter?
[Answer]
# Use low temperatures.
For a given system, we can tell if degeneracy pressure is important by [comparing the Fermi energy $E\_F$ to the thermal energy $kT$](https://astronomy.stackexchange.com/a/15049/2153). if $E\_F\gg kT$, the gas is fully degenerate; even $E\_F\sim10kT$ will apparently lead to at least partial degeneracy. As the Fermi energy scales as $E\_F\propto \rho^{2/3}$, and (non-relativistic) degeneracy pressure scales as $P\propto\rho^{5/3}$, where $\rho$ is density, it should be clear that if your substance is quite cold, you can achieve degeneracy at lower pressures.
Consider a [gas of electrons](https://en.wikipedia.org/wiki/Fermi_gas) (not a gas in the usual sense) at $T\sim 10\text{ K}$. This has a thermal energy of $kT\approx8.6\times10^{-4}\text{ eV}$. Let's assume that full degeneracy occurs at a Fermi energy of $E\_F\approx100kT$. This requires a surprisingly low density - only $\rho\approx1.05\times10^{-7}\text{ g cm}^{-3}$. Calculating the degeneracy pressure shows that $P\sim10\text{ Pa}$, which is clearly substantially easier to achieve.
] |
[Question]
[
In this world homo sapiens lose their eyesight but have the ability to sense the surrounding with biosonar similar to whale and dolphin, I wonder if we could have discover electricity but suppose the setting is in the late 18th to mid 19th century A.D, how would transportation looks like? I assume we still need to cover distances across difficult terrain and large bodies of water so I hope to get some useful tips in designing the kinds of transportation in such a world. Also A.I research is still at its infancy so I am looking for commercial types of vehicles.
[Answer]
If you have to use echolocation, you cannot afford solid surfaces blocking your line of sight.
This means forget about glass windows if you want to perceive the outside of your vehicle.
First cars and airplanes had their driver/pilot exposed to the outer environment, thus there would be no issue for those heroic gentlemen. But as soon as they want some shelter from the outside you are in troubles, and I think you can also forget about pressurized cabins in airplanes.
Additional complication would come from the noise of the engine, which was pretty loud in the early models of both cars and airplanes. It is possible that more effort would be put in researching proper acoustic insulation and dampening (nobody IRL likes to drive with light shining in their eyes, right?), resulting in quieter engines.
And I am also pretty confident that talking to the driver/pilot would be highly frowned upon for very similar reasons.
[Answer]
The early fliers would not use any windows in their planes so they would have an unrestricted echo location “view”. These planes would probably not fly very high as they would want to be able to echo locate the ground and landscape.
Before long instruments would be developed that gave them an artificial horizon, altimeter, air speed indicator and compass. At this point it would be much safer to travel higher on instruments. On returning to low altitude they might slow down and “open the window” so they could echo locate for landing.
Eventually artificial long range echo location would be developed like radar/sonar allowing even greater control. There might be an intermediate step where high energy ultra sound was beamed at the ground to allow these creatures to see beyond their normal range.
With modern instruments there would be no problem in having a pressurised atmosphere even at altitude, however there might well remain the last step of pressure equalisation followed by opening the window for landing.
] |
[Question]
[
I have several stories where I've wanted a moon in some weird orbit that is not allowed by orbital mechanics. In the past, I've had to change stories to bow to physics.
Today, I had a thought while looking at photos of Saturn's moon [Enceladus](https://en.wikipedia.org/wiki/Enceladus). As it orbits, Enceladus gets compressed by Saturn. The compression squeezes out jets of water that [rain down on Saturn](http://spaceref.com/saturn/saturns-moon-enceladus-jets-affected-by-its-orbit.html), refreshing the rings. See image below taken by [Cassini](https://en.wikipedia.org/wiki/Cassini%E2%80%93Huygens). Pretty neat.
I started thinking, "What if those jets were like rockets, pushing the moon?" I know that's not viable: the amount of water coming out of Enceladus is tiny compared to Enceladus' mass, so this example isn't going to cause any meaningful shifts to the orbit, so far as I know. And any ejection that was sufficient to skew orbit wouldn't be particularly repeatable (the moon would run out of mass pretty quick).
But physical propellant isn't the only way to do stationkeeping. Could there be some sort of natural event on the moon (for example, a naturally occurring nuclear explosion), something that happened with some regular cadence, of sufficient strength to push a moon on its orbit? Can we construct a moon that has natural stationkeeping such that its orbit is one that would normally crash or fly off, but because it gets a regular bump from some other force, it is able to maintain its orbit?
Whatever gets proposed is likely improbable, but I'm looking for possible.
**Summary: Is there a natural, repeatable process that could somehow become sync'd with a moon's orbit that would provide stationkeeping ability to sustain the moon in an otherwise impossible orbit?**
[](https://i.stack.imgur.com/svgMX.jpg)
[Answer]
No not to any significant extent. The forces required to drive even a small moon like Enceladus would be too large. And even if such a massive force were available it would need to be applied continuously for station keeping beyond the moons natural orbit. As soon as the force was no longer applied the moon would simply continue in its new orbit only affected by gravity.
In a similar way a rocket can change its orbit by firing its engine but as soon as the rocket’s engine is turned off the rocket will revert to an orbit purely dictated by gravity. An impossible rocket with a portal on board capable of supplying endless amounts of propellant could continually overwhelm gravity and could for instance move around a planet faster or slower than would be predicted by a classical orbit but any such portals are beyond physics as we know it.
[Answer]
One could postulate the recent capture of a Kuiper Belt object that got turned into a long period comet, maybe a capture via recent collision with a previously resident moon. With a large reservoir of ice and new exposure to sunlight one might get enough assymetric jetting to alter the object's trajectory significantly from purely orbital motion. This gets easiest to envision near the planet's Lagrange points where it takes very little delta V to produce relatively large motion changes. One could envision the impact site with the resident smaller moon leaving a large crater and throwing out a debris blanket on one side of the KBO to set up the asymmetric jetting conditions. This is very unlikely of course, but within the bounds of the possible over the time span of interest.
[Answer]
Yes, sort of. Two small moons of Saturn, Epimethus and Janus, [swap orbits every four years](https://www.planetary.org/blogs/emily-lakdawalla/2006/janus-epimetheus-swap.html) (Earth years, not Saturn years). Neither moon could have the orbital path that it has if the other moon were not there. So the “natural process” you’re looking for is simply the existence of another moon.
[Answer]
**WHAT IF**
From your question I can assume this isn't already a normal system.
As such, if a moon had been part of multiple bodies instead of just one (or the other bodies came in at a later time), these other bodies could impact with the moon (or have impacted) to keep it out of alignment.
So, for example, Moon A is the moon that's currently orbiting our main body. Let's assume it was originally orbiting in a semi-normal fashion around its parent.
Along comes object B. This body zips around the parent and goes past the Roche limit, fragmenting into a series of smaller objects which continuously slam into Moon A pushing it against it's normal gravitational pull and keeping it at an 'extreme' orbit.
This obviously would not be something that would last forever, but there could still feasibly be remnants of object B due to impact into A for quite a period of time.
] |
[Question]
[
I was thinking of a situation, in which there is a mass extinction that wipes out all large land animals, and after this mass extinction some of the descendants of modern geckos evolve to fill the niches left by the large mammals. Some of these descendants of geckos also evolve to walk on two legs similar to how some dinosaurs walked on two legs during the Mesozoic
I understand that human thumbs were originally used to help with climbing trees before getting used to hold things when the ancestors of modern humans started walking on two legs. Geckos use van der waals forces to help with climbing trees as they have hairs on their feet that have hairs on their hairs, and so on down to the molecular level.
Just as human thumbs originally evolved for climbing and then got used for holding things in our hands could the van der waals forces that geckos use for climbing be used for holding objects in the hands of descendants of geckos?
[Answer]
There are two ways to go about handling this problem - one that keeps van der Waals forces and the other that loses it.
As you've pointed out van der Waals (more like van der *Walls*) forces help geckos stick to walls. What this force is is basically an attraction formed due to the polarity between two surfaces (i.e the gecko and the surface of the wall). Now this is isn't as strong as Dipole dipole forces but much stronger than London Dispersion forces.
So assuming your future-geckos hold things with their hands like we do, this means that we want to improve their dexterity. To improve dexterity, I would recommend having very strong van der Waals forces on some part of their hands versus others, acting a bit like the grip on the bottom of shoes. Just having van der Waals forces could create problems - if you just had van der Waals forces on all parts of your hand simple things like throwing something may not just be difficult, but almost painful if the polarity between your hand and the object is great enough.
How strong this force is depends on the [complex arrangement of hairs](https://www.sciencemag.org/news/2002/08/how-geckos-stick-der-waals) on the feet of geckos. So this would mean that eventually the future-gecko's hands would have either an **overall less-dense arrangement of hairs** or have a **very dense arrangement of hairs at specific parts of the being's hands** to maximize the effectiveness of different kinds of grips.
Keep in mind that there's the chance that **future-geckos lose the ability to grip onto walls entirely because they don't do that anymore**. We don't have van der Waals forces helping us out - we do fine with our mostly-bare skin on our palms. Being reptiles, there's a chance that the flexible/elastic nature of reptilian skin would be a good enough grip so that the future-gecko's hands also become hairless.
[Answer]
You can get around the problem by getting your geckos to evolve human-like hands with more dexterity, and lose the Van der Wall forces.
Since they're filling the niches formerly occupied by humans and other large animals, that would mean they're now more land based. This can create an evolutionary pressure towards hands with dexterity over hands that let you climb trees. Geckos already have five 'fingers', so it's not far-fetched to imagine that they'd evolve them into hands resembling ours complete with an opposable thumbs.
In fact, this would actually be more meaningful than keeping the Van der Wall forces. Again, since they're going to be occupying land, there's a good chance they'd evolve into bigger body sizes. This would mean we can even have them as big as monitor lizards or bigger; I'm not sure about the math, but it is entirely possible that there's a maximum weight after Van der Wall forces cease to be effective. So you could argue that with the incentives the newly vacant land promises, there's an intense evolutionary pressure towards ditching Van der Wall forces and evolving 'better' hands.
] |
[Question]
[
I am thinking of writing a story about a Martian civilization. It might involve humans, but, I think it will be more interesting if there are creatures adapted to the Martian lifestyle as well. So, here is a proposed creature to live on Mars:
[](https://i.stack.imgur.com/SWZHc.png)
A burrowing reptilian, or so it seems. Photosynthesis is a tricky one. On the one hand, less light arrives at Mars than at Earth. On the other hand, the thin atmosphere means the light doesn't get as scattered. I decided that this creature would have photosynthetic skin, because it means the creature wouldn't have to worry as much about being sunburnt. When the creature is likely to be cold-blooded, that is important. Also, this can provide oxygen for the creature to survive since Mar's atmosphere is almost entirely carbon dioxide. I mean, yes, the creature would be more adapted to an anaerobic lifestyle, and when hibernating would probably go full on anaerobic, but, when active, it probably won't be fully anaerobic.
There are light sensors on top of its head, these connect to the part of the brain responsible for circadian rhythm. When they sense light, the creature wakes up. If they don't sense much light for a few hours, the creature goes back into its burrow to sleep. If after a day or two, there still isn't much light sensed, because, say, there is a global dust storm, the creature goes into hibernation. The Martian winter also forces the creature into hibernation but for a different reason. The Martian winter, even at the equator, is way down in the negatives. At night, it gets much colder still. An active creature during the Martian winter, if it isn't tiny, is going to freeze like an ice cube. Hibernation means that the little geothermal energy there is on Mars will be enough to prevent the creature from freezing to death in the winter.
As I mentioned already, this is a burrowing creature. It also is a nesting creature. This creature lays eggs during the spring, so that its offspring have plenty of time to prepare for hibernation. Because the chance of a global dust storm during any Martian year is 1/3, those that are unlucky to hatch during a year with a global dust storm will not survive, because they aren't well prepared enough. But, most hatchling deaths do not have to do with global dust storms happening at the wrong time. More are from lack of food, deformity, and predation than from global dust storms.
As the hatchlings grow, they rely less and less on aerobic metabolism. And the hatchlings start off tiny enough that photosynthesis can easily provide oxygen to all the cells, so oxygen storage isn't a huge concern for this creature. An oxygen storage system still develops though, while it is an embryo, just in case it has to flee or defend itself and thus needs extra oxygen that photosynthesis alone can't provide at a fast enough rate.
And this brings me nicely to the eggs themselves. When an adult eats another creature(yes, they go from complete autotrophs to a combination of an autotroph and a heterotroph as they grow and photosynthesis can't provide the full metabolic demands anymore), they inevitably will eat some iron oxide dust in the process. Instead of discarding all that iron in their waste products, in females, when they ovulate, some of the iron gets used to make egg shells. And because the egg shells are iron rich, they virtually blend in to the Martian landscape, which on the one hand, makes it much harder for predators to spot them without sensing infrared, but on the other hand, makes other burrowers more likely to damage the eggs, so the females will strategically place their nesting burrows to avoid this damage from other burrowers.
**What do you think of my proposed Martian creature? Of course, there would be many more, but I can't ask about all of them. Is this a plausible creature to live on Mars?**
[Answer]
First of all - no any photosynteses:
* even here on Earth photosynthes is not an option for any animal. It would cover merely percents of animal energy (i.e. oxigen) needs. It is effective for plants because they do not move or actively pump anything.
* Mars has times lower solar energy on its surface compared to Earth. Plus it has those dust storms - they are not dangerous in terms of wind pressure (you will bearly feel it with your naked skin), but they close skyes form Sun for months. And even in an anbiosis sleep animal do need oxigen.
Since photosyntes is a key feature of your organism - it is not plausable.
I suggest you to "split" this organism in two living in symbiosis like ants and aphids. But instead of aphids there should be "fields" of plants wich accumalates spare oxigen in some sacks or some other way of transfering oxidiser to "ants" through feeding. "Ants" are "responsible" for spreading fields and keeping seeds undeground in winter.
UPD (due to comments):
Why do such creatures exist is completly out of scope of asked question (plausable or not?). For me it is more like artificial creature: may be humans , may be aliens do some biological experiment on Mars. So I asume no other biosphere is present and no Mars terraforming were held. Mars is as it is now.
[Answer]
**Maybe**
You might be able to get away with this if your animal has a unique life cycle.
For example, maybe it is dormant for long periods of time, and its burrowing consists of digging itself into the ground to the point where only its armoured, photosynthetic back is exposed. It waits for days, weeks, months, whatever, generating enough energy to keep a very slow metabolism going while it uses the converted oxygen to create oxygenated egg materials for its young.
The young get laid in a depression under its belly, then the thing just continues generating energy in the form of heat and food for the young. When the young are born, they burrow into the body of the parent, killing it but getting nutrients and oxygen from its body. When they are old enough, they emerge and instinctually move to new areas, where they burrow in and repeat the process. The mobile part of life is very small, and uses up the energy they retained from Mom.
Mating might be done by having the first ones to burrow in a new area have some color or shape that identifies them. Maybe the males are smaller and not photosynthetic, and they live just long enough to impregnate the females, becoming food for them because in that hostile environment every joule counts.
If you want something more sophisticated, consider something like an anthill or a beehive, where instead of 'workers' you have photosynthetic castes which climb to the top of the hill and spread out around it. Other, more mobile castes bring them some kind of nutrient and water, and in return the photosynthetic ones produce sugars that the hive lives on, and cumulative body heat from all the animals in the hive keeps the temperature reasonable, just like anthills on Earth. Something like that.
But a normal, mobile insect or reptile? Nope. Not enough energy.
[Answer]
The "light sensor controls activity" part won't work. If the the creature has burrowed into the ground to preserve heat, it won't be able to see light outside the burrow. Unless you want to claim that it somehow creates windows in its burrow.
] |
[Question]
[
I'm writing a fantasy set in our world but an alternate timeline where a magical force has 'leaked' into our world from an alien one. The magic is based on science in that the magic is simply energy that can be harnessed to effect known forces that exist.
Certain humans are able to harness the magic by 'conducting' it through their bodies (as long as their feet are on the ground). Rather than being tedious about the detailed types of magic I've built, I'll get on to the crux of my problem. In my original outline, I imagined a type of mage more exponentially powerful than other mages who is able to create black holes (usually resulting in suicide) and destroy cities and armies. I have called this magic deathlight and it can be countered by something I call starlight. As I've written it, the deathlight looks like a void that can expand until it reaches its pinnacle, pulling all nearby matter into its heart before disintegrating. The starlight 'feeds off' the deathlight, pulling its energy away. When these two energies clash, the more powerful mage prevails.
Obviously this is magic so I can do what I want. But I would prefer my magic to at least resemble known universal phenomena.
I have a scene where the beloved Sultan is meeting with some emissaries from a foreign Empire. One of the foreigners is a traitor with bad intentions. The Sultan knows this for (plot reasons) and confronts him. However, it turns out the traitor is actually an assassin ready to take out the Sultan then and there. MC is the Sultan's guard and when the cornered villain casts the deathlight she attempts to counter it with starlight but she doesn't have sufficient knowledge to cast a large enough counter, she only manages to hold the deathlight off long enough for (other characters) to shield her and themselves before the deathlight explodes, taking dear old Sultan and mr. baddy with it. When's all over they are surrounded by a crater, except for the tiles and rugs where they were standing under the shield.
Can this make any sense using our world physics, assuming there are no limits of energy or mass as we know them? What would make this scenario more realistic without simple ignoring the issue of radiation?
Do you have a better idea? :) Thanks for reading.
I originally tagged this as science-based because my magic does have limitations based on the natural laws of our world (up until I get to the black hole goes boom scene). I really want my world to be consistent and grounded. I'm ready to throw the black hole out but I just haven't thought of anything better. To anyone interested here's a brief summary of my magic system:
Worcraft- of manipulating plant life
Orecraft- of combining molecules and elements
Shapecraft- of transfiguring the form of object (without changing their material)
Bindcraft- tethering or severing the consciousness's connection to an object
Ligtcraft- of manipulating or creating light
Leechcraft- cleansing or staunching blood flow
Soughcraft- of the augmentation or reduction of sound
Toolcraft- the manipulation of gravity
Ondyng- the manipulation of scent
[Answer]
# Deathlight is a tear in reality: starlight is thread
Rather than having deathlight be a black hole, which involves all sorts of unpleasant side effects, instead, have deathlight be a tear in reality —or rather, many, many little tears.
In certain theories, reality, or our dimension, is *already* swiss cheese: there are gaps in it through which *gravitons*, the hypothetical particle that causes gravity, can slip into. It only works for gravitons because they’re so tiny, but what Deathlight does is widen those gaps, so that regular matter can also vanish into them. The area in which it happens spreads from the origin, and the only way to counter it is to use ‘starlight’, which acts like thread around a tear, pulling the gaps closed. Of course, if the tears spread faster than you can stitch, everything gets eaten up.
As for the explosion at the end: when the mage wielding Deathlight dies, their hold on the spell fails, and the world reverts back to normal. Of course, the dimensions which are big enough to contain gravitons certainly aren’t big enough to contain real matter, and everything that vanished is spit back into the real world, with catastrophic results.
[Answer]
**Antimatter is a better solution than black holes**
From the description you've given of the Sultan scenario, considering that black holes don't really explode, this sounds more like antimatter to me. Antimatter, of course, reacts violently with matter. To the point where a gram of antimatter reacting to a gram of matter is equivalent to ~43 kilotons of TNT. Obviously, that too much, your characters would most likely use a fraction of that, maybe even as little as a trillionth of a gram, though you don't have to go into specifications. In other words - deathlight = antimatter.
Starlight is the process needed to transmute the matter into antimatter. The way it's created on Earth uses particle accelerators, but a mage wouldn't need to do that - just snap your fingers, and the protons and electrons suddenly swap to positrons and p-bars (that is, anti-electrons and anti-protons). And to keep summoned deathlight from exploding, you can use starlight to overcome it and turn it back, or you can use magentic magic to isolate it and keep it from interacting with normal matter. You may wish to call it twilight - the light that separates light and dark.
[Answer]
I think this question is unavoidably opinion based because controlling black holes is never going to be science-based, nor is anything which can feed off them. See the *Heroes* character [Stephen Canfield](https://heroes.fandom.com/wiki/Stephen_Canfield) who can summon black holes at Will, like your mage.
But your very final question has an answer.
>
> What would make this scenario more realistic without simple ignoring the issue of radiation?
>
>
>
The answer is nothing, because radiation will never leave the black hole in real life. You will have to rely very heavily on your magic to suspend disbelief in this story. What your magic does is tunnel the energy falling into the black hole somewhere else (like a wormhole). That someplace else has to be outside our universe. Lucky for you, that place already exists! So the “Starlight” weapon tunnels the energy back into this universe.
Basically your magic goes around the event horizon by connecting the two realities “leaking” over each other.
[Answer]
small black holes evaporate. The smaller the hole the faster they evaporate. So the rate at which matter can be conjured into the black hole is critical if a massive enough amount can't be added quickly enough there will be a big explosion.
You might find the answer to this question of interest:
[Would it be possible to have a small black hole dissipate as it 'sinks' into the earth?](https://worldbuilding.stackexchange.com/questions/94244/would-it-be-possible-to-have-a-small-black-hole-dissipate-as-it-sinks-into-the/94250#94250)
] |
[Question]
[
I think it would make sense for hurricanes to be combatted using shade balls to block the evaporation of the ocean into the storm.
[What would we need to stop a hurricane?](https://worldbuilding.stackexchange.com/questions/57705/what-would-we-need-to-stop-a-hurricane)
[Info on shade balls.](https://openshadeball.org/)
[Answer]
# No
This is just like using DDT against mosquitoes. It sounds like a Nobel winning idea until the consequences make it an igNobel winning idea.
By blocking sunlight over a large area you are also blocking photosynthesis over a large area. The wildlife under the shade will not be thankful.
Also, if you don't tie the whole batch of balls they will just be picked up by the hurricane. If you do tie them, then due to currents, waves and the strong winds over it the whole thing will likely fold upon itself, becoming a deathtrap for fish, turtles and cetaceans.
---
Hurricanes are made stronger by global warming. The decimation of phytoplankton through shading, which effectively reduces the trapping of carbon in the ocean, goes counter to that.
[Answer]
## Theoretically Yes, Practically No
I'd say the theory behind this idea is sound. Lower the water temp and reduce humidity in front of a hurricane, and that will sap it of power over time. However, the sheer scale of hurricanes makes this infeasible to put into practice.
Los Angeles used 96 million shade balls to cover its Las Virgenes Reservoir. That reservoir is less than one mile square. Hurricane Andrew, which wrecked South Florida back in 1992, had tropical-storm force winds (36mph sustained) 90 miles wide, which is notably compact for a cyclone. Tropical Storm Nestor, which is making landfall on the Florida Panhandle as I type, is about 150 miles wide, at least per the NOAA wind map. Hurricane Irma, which hit Florida in 2017, at one point had *hurricane*-force winds 80 miles wide, with tropical storm-force winds extending well over 200 miles wide.
The LA reservoir had the balls packed several layers deep, so let's say we only need 25 million balls to cover a square mile with one layer. To have an effect on a small hurricane, let's say you'd be looking at a more-or-less circular patch of ocean 100 miles wide. The area of that circle would be pi\*50^2 ~= 7,850 square miles, so you'd need upwards of 200 *billion* shade balls.
The city of LA paid about \$0.33 per ball, so we'd be looking at something like $65.4 billion to buy all of those shade balls. At that point, it actually becomes cheaper to just let the hurricane hit and clean up the mess afterwards.
[Answer]
## No
It's a matter of scale. The shade balls I looked at are 4" in diameter. That means a cubic foot of them contains 27 shade balls. Therefore, 200 billion shade balls (100 sq mile circle) would require about 7.4 billion cubic feet of storage space
A standard 20 ft cargo container has 1150 cubic feet of space. To store all the shade balls, you would need 6.4 million standard cargo containers.
The largest cargo ship in the world is the OOCL *Hong Kong*, and it can carry 20,000 cargo containers.
So you would need 322 of the world's largest container ships just to carry the shade balls. And you'd have to sail them into stormy seas to deploy them in the region of a hurricane. Hurricane tracks and formation are still fairly unpredictable, so you'd need to spread them over a gigantic area. Then you would need to be able to unload 6.4 million cargo containers worth of shade balls quickly, and get all those slow, lumbering ships out of the hurricane zone.
Picking up the shade balls after they have been transported around for days by wind, waves, and currents would be a global-disaster-sized cleanup job, unless you can come ip with a shade ball that will rapidly decompose in sea water, and 200 billion of them decomposing in water doesn't damage the ecosystem.
It would probably be easier to use deployable sun-shades in space to deprive a hurricane formation region of solar energy. Not that even that is a good idea, but it would be easier than putting the shade on the water.
] |
[Question]
[
**This question already has answers here**:
[How would you make a universal measurement of time?](/questions/106030/how-would-you-make-a-universal-measurement-of-time)
(6 answers)
Closed 4 years ago.
I have recently been trying to come up with a measurement of time, such as years, seconds, etc, that can be used irrespectively of galactic location and universe location.
Star-treks stardate was quite an elegent, albeit fictional solution. Reading articles such as [How Stardates work](http://mentalfloss.com/article/68741/how-do-star-trek-stardates-work), a stardate still fundamentally has the roots in Earth's perception of a century, related to the birth of Jesus, this obviously is not transferable to other worlds.
Because relativistic properties are almost minute for speeds less than $\frac{c}{10}$ [Formulation of speeds that start to require relativistic properties](https://physics.stackexchange.com/a/185118/153765), and that speeds of bodies within a galaxy such as our sun are around $\frac{c}{1300}$, got from a [galatic year](https://en.wikipedia.org/wiki/Galactic_year), my original thought was that:
1. The datetime format could be prepended with a galaxy identifier
2. Then add maybe some rotational number of the galaxy since its birth
But then I am not sure how to progress into measuring the rotational number, and that it also needs a time measurement since the big bang and the birth of the galaxy, which then begs the question of at what stage can a galaxy be considered to be birthed?
Another perspective is that our [current definiton of a second](https://en.wikipedia.org/wiki/Second), and I then got led onto an [optical lattice clock](https://physicsworld.com/a/optical-lattice-clock-shatters-precision-record/), but I am still unsure of how to apply these universally.
Any help or suggestions would be great.
[Answer]
You want a system that everyone across the galaxy can observe together and has a regular periodicity. The solution is [**Pulsars**](https://en.wikipedia.org/wiki/Pulsar)
Pulsars are highly regular rotating neutron stars that emit beams of electromagnetic radiation from their poles. While not all pulsars are good enough for the most precise time keeping, the regularity of millisecond pulsars is [even more precise than the most precise atomic clock.](http://aa.springer.de/papers/7326003/2300924.pdf)
For example, the brightest one in our sky is [PSR J0437−4715](https://en.wikipedia.org/wiki/PSR_J0437%E2%88%924715) rotating every 5.75 milliseconds at a distance of around 510 lightyears. Civilizations wanting to synchronize their clocks could refer to the number of rotations of this pulsar since record keeping began.
[](https://i.stack.imgur.com/VfcKF.png)
Source: <https://en.wikipedia.org/wiki/File:Pulsar_schematic.svg>
[Answer]
Why do you need a universal time measurement?
You can treat time intervals (such as years) as we treat currencies between countries. You have to pay tax to Empire Capital at Earth per one earth-year? Just convert that time measurement to your planet's years and collect local taxes on basis of that.
I would argue that one a multi-starsystems empire you cannot have many things universal as we can have on earth. For example, currency. You just have to trade on basis of what a particular planet want AND what do you want. Same would have to work for taxations. As in Foundation Series by asimov Earth may be more interested in some agricultural crop that you have plenty of, so trade in that, and give taxes in that, not in any currency.
When you are travelling you primarily focus on spaceship time, when you land at some planet you take into account time there but only as long as you stay there. Once you are in space again you dont worry about length of their days and durations of their years and number of crops they can have per their-year and so on. Empire Center should also not worry about such locality-specific matters, especially when it has a multi-star empire to manage. It need to worry only about what it can get from each of its province-planets in taxes and in trade etc; and what it has to give back to them, basically in security, and let locals administer themselves. Just control some key resources and you are ok.
[Answer]
Time is nothing but events. If you have any idea how much time passed between two events it's only because other events happened between those events.
Since your time measurement is meant to be universal let's make it about the universe. It started with the [big bang](https://en.wikipedia.org/wiki/Big_Bang) and it'll end with the [heat death](https://en.wikipedia.org/wiki/Heat_death_of_the_universe). So why not just measure every moment in time as some value between 0 and 1 between those events? This sets [the bounds of our system](https://en.wikipedia.org/wiki/Graphical_timeline_from_Big_Bang_to_Heat_Death).
Or between 1 and 0 so we can have a good countdown. Well crap, so much for universal. Now people will have an [endian war](https://en.wikipedia.org/wiki/Endianness#Etymology) over which to use.
As for the events between 0 and 1, I recommend something everyone can observe, which excludes pulsars that have to be pointing at you to work. I recommend an atomic clock and an accelerometer so you can predict what an atomic clock at rest would have measured. That lets you standardize the precision of the system.
As for synchronizing the more macro "when we are" event I'd look for a unique event such as the gravity wave created when black holes collide. Periodic events risk arbitrary choices of when to start counting.
] |
[Question]
[
So I have the following scenario for a story, and I want to know if it runs into any ridiculous no-nos from a scientific point of view:
There is an earth-like world orbiting a red dwarf (similar to [AD Leonis](https://en.wikipedia.org/wiki/AD_Leonis), though it is not tidally locked. It doesn't have to be *hospitable* but does have to be *habitable* (there will be other factors drawing humans to this world). It's much colder than earth, maybe only habitable in a narrow band around the equator, and with a lower gravity (say 0.8 g, somewhere in that neighbourhood).
Smaller worlds are more likely to be in tight orbits around a red dwarf from what I understand so it'll be the third planet in the system with an orbital period of ~190 (earth) days (close enough to half an Earth year to make it easy to count). Days would be a bit longer, maybe 29 hours or so.
The most important parts are that it is possible to survive, if not exactly comfortably, outdoors, and that reaching orbit is at worst as much work as it is here on Earth. A smaller planet with lower gravity (assuming close to as dense an atmosphere as Earth) should make it a little easier to get things into space.
Here is the rest of the system (briefly), from star and going outwards:
* 1 hot molten (lava) world
* 1 cold rocky world
* 1 Earth-like world (described above)
* 1 gas giant
* 1 gas giant
* 1 cold gas world (Neptune-like)
* 1 tiny rock-world (Pluto analog)
* Cometary halo and asteroid belt
[Answer]
I can see four key problems with the system as you've described it:
* **Giant planets**. The major thing that concerns me about the system is the presence of at least two gas giants. It's long been thought that low-mass stars like red dwarfs are unable to form giant planets, because the stars' protoplanetary disks are generally low-mass, and there's simply not enough material to form as many giant planets as in other systems. There are some counterexamples, like GJ 3512 ([Morales et al. 2019](https://science.sciencemag.org/content/365/6460/1441)), but these are general few and far between.
* **A lack of tidal locking.** Planets around red dwarfs are likely to be tidally locked, for two reasons. The [timescale for tidal locking](https://en.wikipedia.org/wiki/Tidal_locking#Timescale) scales as $\tau\propto a^6/M^2$, where $a$ is the planet's semi-major axis and $M$ is the mass of the star. If you have a planet with a tight orbit around a low-mass star, as we do here, the planet will be tidally locked quite quickly, possibly long before life has a chance to arrive.
* **High-multiplicity systems are problematic.** You have seven planets orbiting this red dwarf, presumably in tight orbits. The closest analog I can draw to this is [TRAPPIST-1](https://en.wikipedia.org/wiki/TRAPPIST-1), which hosts seven planets, much like this system. The orbits are stable only because the planets lie in orbital resonances with one another (i.e. the ratios of their periods are ratios of integers). The problem is, even a system with such resonances may develop instabilities on timescales of tens of millions of years ([Gillon et al. 2017](http://adsabs.harvard.edu/abs/2017Natur.542..456G)). The presence of massive planets in particular makes me a little nervous. Keep in mind that the masses of the TRAPPIST-1 planets are comparable to Earth or lower ([Grimm et al. 2018](http://adsabs.harvard.edu/abs/2018A&A...613A..68G)).
* **The Earth-like planet may not be habitable.** Given the 190-day period, I derive a semi-major axis for your planet of 0.48 astronomical units. Calculating the planet's [effective temperature](https://en.wikipedia.org/wiki/Effective_temperature#Surface_temperature_of_a_planet) tells me that it should be about 157 Kelvin, give or take, given the luminosity of AD Leonis. This means that the planet would have to be closer to the star for the surface temperature to be right without a massive runaway greenhouse effect.
To mitigate this, you might consider placing the giant planets in orbits far from the star, away from the other planets, to prevent instabilities. Similarly, the Earth-like planet could also have a large semi-major axis, to increase the tidal locking timescale (even doubling $a$ increases the timescale by a factor of 64); unfortunately, this would then make the planet colder and uninhabitable. I don't have a great solution to the issue of gas giant formation, but perhaps some external source of matter could be responsible.
] |
[Question]
[
I'm conceiving of a world where humans can readily terraform worlds that were once considered "dead" due to the planet's magnetic field being long gone. In such a situation, what could humans do to recreate an artificial magnetic field to protect the planet.
I know it's relatively easy for us to create magnetic fields stronger than that of the earth in a lab, but it's unclear to me how this could be replicated on a planetary scale given an 1/r^2 strength of field over distance
My simplest idea would be a supercooled solenoid running around the planet to generate a magnetic field similar to that on earth. However, I'm not sure how to account for the planet in the center.
[Answer]
Apparently, the amount of energy needed to shield Mars from the solar wind is less than one might think. There was a proposal to build a device that could project a magnetic field that would deflect the solar wind from Mars, potentially allowing a terraforming project to take place.
In a nutshell, the device would be placed in orbit at the L1 point between Mars and the Sun. It doesn't need an infeasible amount of energy to work - the magnetic field would be 1-2 Tesla, less than a MRI scanner. This could be provided through a superconducting magnet and powered by a PV array that could be constructed with today's technology.
<https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html>
] |
[Question]
[
[This answer](https://worldbuilding.stackexchange.com/a/150510/40408) to my last question suggested, rightly, that there are targets dangerous, and large scale, enough that there is neither overkill nor spillover damage when it comes to attacking a planetary target. This is usually a variation on [grey goo](https://en.wikipedia.org/wiki/Gray_goo), sometimes organic and sometimes technological but almost always able to survive in space as well as on an otherwise habitable world.
We're pretty sure that if something hits [some](https://en.wikipedia.org/wiki/Mars) planets hard enough [pieces](https://en.wikipedia.org/wiki/Martian_meteorite) come off and go into interplanetary space. Mars is relatively small and airless and I'm interested in a habitable, Earth-like, world; we're also pretty sure that the [Chicxulub](https://en.wikipedia.org/wiki/Chicxulub_impactor) blast *did* put out ejecta that got at least as far as the moon. That blast was caused by an object estimated at 60km across well above the size generally depicted for kinetic weapons carried on or used by star ships.
So the question is, assuming a hardened pathogen (one that can survive both the impact itself and an extended trip through space), what is the upper limit on the magnitude of a single impact during a kinetic orbital bombardment to ensure that such material is not spread beyond the world being bombarded, is impactor speed or size more of a factor or is it purely a matter of the total magnitude of the blast produced?
I'm assuming that any ejecta that reach [escape velocity](https://en.wikipedia.org/wiki/Escape_velocity), just over 11kms-1, are going to be a potential vector.
[Answer]
Data by [Berthoud et al, 1997](http://adsabs.harvard.edu/full/1997M%26PSA..32R..13B) [Meteoritics & Planetary Science, vol. 32, n. 4 supp. p. 13] as well as by Oberbeck and Morrison (1976) seem to indicate that the maximum speed of massive ejecta might approximately range from 50% to 75% that of the initial impactor depending on impacted structure and angle of attack.
Additionally, this velocity is imparted at impact, therefore at sea level; the ejecta then need to overcome atmospheric resistance, i.e. keep escape velocity when at an altitude of roughly 10 km. This would indicate a "safe" limit for Earth of around 17-19 km/s.
This means that is *way* easier for Martian tephra or ejecta to reach Earth than it is for Earth (or any habitable planet, with a reasonable gravity and atmosphere) to reach Mars, or anywhere else.
Indeed, Chicxulub ejecta reaching the Moon is at the far right of the probability graph for the estimated velocity of the Chicxulub impactor (20 km/s).
Also, unless they have some sort of in-flight shaping capability, the smaller an object the greater proportionally its atmospheric resistance (the section goes down as the square of the radius, the kinetic energy is dependant on mass which goes with volume, as the third power of the radius). So grey goo could only escape if embedded in larger, aerodynamic ejecta. Utility dust and "dry goo" would only go as far as the actual atmospheric displacement - it would surely reach the stratosphere riding on the fireball, but once there it would have zero velocity and fall back after a while.
So, a very large and dense penetrator with speed below escape velocity **ought** to be both effective and safe. **You will probably never have absolute security** because secondary phenomena (explosions, etc.) might still supply higher velocities.
For your grey goo suppression needs, I suggest tuned lasers or gigantic Joule resonators, or chemical or radioactive warfare approaches.
On the other hand, if the grey goo is capable of self-assembling in flight and has sufficient energy or fuel storage capability, it could actually *exploit* the impactor - reach the stratosphere as a dust cloud, then condense in a needle-like aerodynamic structure, and start ejecting part of the structure's own mass to achieve reaction propulsion.
] |
[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.
I'm building a S-Type binary system where the primary star is a black hole. Yet the system formed as a O + K-Spectral class binary and the 20 solar-mass O giant went nova 2,7 myr after both the stars had transitioned from T Tauri tars to the main sequence after ca. 50 myr, like our sun did. Planets around the 0.78 solar-mass K-Type star should have almost reached their final composition and masses at that time. When the supernova happened the K-Type star was 2,8 ly away from it's partner. Assume that the systems plane of the ecliptic was aligned with the O-Giant.
# What where/are the immediate and long term effects of the supernova on the system?
Edit: Added the hard-science tag after the first answer, because I would like to see some numbers backing up peoples claims. Some back the envelope calculations would suffice, no need for complex math.
[Answer]
**At only 2.8 light years away, life is toast.**
Most scientists believe that the minimum safe distance from a super nova would be around [200 light years away](https://www.newscientist.com/article/dn2311-supernova-poised-to-go-off-near-earth/). As close as you're talking, it's probable that the energy release would sterilise any planets around your star system, so life (if it was forming or had formed) no longer exists.
From a practical perspective, what happens to the rest of the solar system artefacts (the suns and the planets) is kind of irrelevant as there is no-one on these planets to see it; even visitors would find these planets barren and hostile, for instance. I suspect that the energy release would strip the atmospheres away from the planets in the first instance, and while they may reform over time, this puts some pretty severe limits on life reforming as well. As for the stars, it's likely that they will also be impacted, but it's unclear as to how. At that distance, the material and energy released could easily disrupt a star and cause massive coronal mass ejections (CMEs) that in turn would cook any planets close in that may have otherwise survived the super nova. While it's possible that a star could be disrupted by having a large percentage of its gases stripped away this is unlikely because of the local gravity well and magnetosphere it generates.
But the thing is, EVERYTHING about a supernova is big. It's hard to conceive of an explosion on that scale and properly understand it. At that range, some stars may well be destroyed but it's important to note that most stars in the core of our galaxy are probably that close to each other and supernovae would have to have gone off many times in that region in the past, and the stars are still shining (or at least their light is still reaching us). So, it's possible that the celestial bodies of your solar system may survive in some form. But life on the other hand at that range is done for.
In point of fact, there's a theory around the timing of mass extinctions on Earth that pretty much says that the chances of a mass extinction while the solar system is actually passing through the lateral disc of the galaxy (as well as orbiting, it wobbles up and down on the Z axis) is around 1 in 2, or 50%. We just passed through that disc about 1 million years ago so we're not thought to be at risk for another 29 million years or so but the very existence of that theory tells us that being in close proximity to other stars is very dangerous to us as lifeforms. All it takes is a single star to go nova close enough to us and not even bacteria can survive on the surface of the earth.
So, while certain celestial bodies may still exist, in the long term their chances of harbouring life again within another million years or so are close to zero.
] |
[Question]
[
There is a sapient jellyfish species resembling the box jellyfish found to be lurking in the ocean today. A team of researchers took a sub and dived into the abyss to look for it. What kind of non-invasive tests (in-situ) can be performed on this jellyfish to see if it is sapient? Don't expect it to talk back or open a jar! However incomplete fossil records show that they could evolve some sort of neuron cells similar to those found in humans and current theory suggests they could be extremely intelligent.
[Answer]
While azerafati's test is the one they should start with, it is likely to fail or be inconclusive. Manipulating objects or showing curiosity in new things may not manifest in the ways we expect.
Your scientists must include experts in animal behavior, perhaps those who also have training in anthropology. Ideally they would set up a research station to observe the jellyfish at length. That may not be possible, due to the conditions, so multiple video cameras are a decent second choice.
Immersion into the jellyfish society is even more difficult to achieve logistically but is the very best way to discover their abilities. Think Jane Goodall and her work with wild chimpanzees.
The method that most scientists would use is the easiest for humans and the one that will yield the worst results (in many ways): capture a few jellyfish and bring them to an aquatic center where humans can easily interact with them. I don't recommend this for real-life wild animals and I certainly wouldn't recommend it for your fictional (or maybe not so fictional, how would we know?) jellyfish.
Emotionally traumatizing beings by ripping them away from their families and communities and putting them in a prison cell filled with unfamiliar things and different environmental conditions is pretty much the worst way to encourage their trust.
Observation in the communities the beings live in is your only hope. For animals we call it "in the wild." This takes weeks to get a sense of where to go next, months before you can start pointing to conclusions. We're talking about a species very different from our own. Chimpanzees are easier to study because physically they're a lot like us and there is a lot of overlap with their emotional states and expression, family relationships, and societal organization too. But jellyfish? This could take a team of experts months or years just to get a handle on it.
Yes, there are tests one might devise that, if the creatures pass them, could be evidence (probably not proof, not yet) that they are sapient. The problem is, not passing the tests means little. Even tests we use routinely on mammals like self-awareness of one's reflection, theory of mind (the classic test is hiding food in front of just one being and then seeing if that being knows if a naive being brought in later knows where the food is), and so forth may just not be relevant for jellyfish.
**The tests that will work are to see how members of the community treat each other.** Theory of mind will come into it, we just don't yet know how. What do familiar relationship look like? (they may not have anything to do with genetic relationships). What power hierarchies are there, if any? How does the community make group decisions? What happens if an individual makes a decision counter to the group? How does the community respond to danger? And so on.
[Answer]
The definition of sapience is often given as follows:
>
> The ability to apply knowledge, experience, understanding, common sense and/or insight to a situation or circumstance.
>
>
>
As such, one would have to understand what consists of normal behavior for said species, successfully introduce one, and only one, variable, and then test for the ability to apply the learned behavior to future situations. Ideally also checking to see if the learned behavior is passed onto others or not.
Given that we are dealing with nonhuman species, understanding what consists of that definition from the creature's point of view is an additional wrinkle. After all, it may be perfect common sense from the creature's point of view to do or think something completely illogical from a human's point of view. Not to mention individual variance.
It would most likely take repeated tests across multiple population groups to collect enough data to indicate the potential likelihood of sapience. Ultimately, viable communication would need to be established as final proof, should the creature or creatures be willing.
[Answer]
They put an Object on the path of the fish which is totally amazing and extraordinary for the fish and monitor it's reaction from a cover or use some hidden cameras.
* If sapient, the fish would surely be curious and show some abnormal behavior toward the object indicating it's intelligence.
[Answer]
You've mentioned that the neuron cells are similar to those found in humans. If so, then it should require a significant size collection of them to achieve sentience. Just look for the jelly fish with the human brain sized growth.
] |
[Question]
[
**Closed**. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers.
---
**Want to improve this question?** Update the question so it focuses on one problem only by [editing this post](/posts/139186/edit).
Closed 4 years ago.
[Improve this question](/posts/139186/edit)
I have seen similar questions about [groundhog day](https://en.wikipedia.org/wiki/Groundhog_Day_(film)) but they were about either a single unique groundhog day or a permanent one.
In this case, each day may or may not repeat. There are no limits so you could have one whole month without repeating followed by the same day repeating ten times. As in the standard groundhog, everyone remembers what happened but everything reverts to the way it was before at midnight.
That means that if the 3rd December is a looping day, at 23h59 you will suddenly be where you were at 0 AM. You will remember everything you did and so will everyone else, but the state of the world will be reverted back. If someone died they will be back, items that were created will disappear, computers will have the same data they held back then, etc.
Everyone remembers every single loop so if a day repeats three times, people will remember the three days of "false/erase" memories. The world has always been that way and it's common knowledge.
Suppose a world similar to our own but that has those random looping. I'm wondering how the legal system would deal with it. I have seen several problems that this would cause:
* If someone is arrested right away and there is a loop they realise they shouldn't have done this now and don't. The officers who arrested him could testify but that raises the issues of police framing people very easily and also the question of whether someone whose crime was erased should have the same punishment as someone whose crime stuck.
* If a looping happen during a trial, would they have to represent the same evidence they already did and hear the same witnesses again, would the jury have to redo their verdicts several times in a row if needed? Furthermore , knowing what happened the previous day would probably affect how the questions to the witnesses would go.
* There would probably also be huge issues with contracts.
For me this seems like a lose-lose situation. You either end up relying on memories and have to fully trust memory witnesses, have incomplete trial records and a hard time checking in the future (even 10 years later, who will remember all the details).
On the other hand, if you want to have records, you have to redo similar things again and again which might influence the results (bored juries, police wasting a lot of time trying to confirm if someone will "recidive", etc.).
What would be a "fair" system that allows appeal and suffer the minimum disruption from looping?
[Answer]
This concept is intriguing.
I have a potential answer, but it depends on a lot of assumptions that are not clarified in the question, and they are too extensive to handle in the comments.
First, I am assuming that there is a philosophical difference between the mind and the body. That is, the mind exists independent of, but reliant upon, the existence of the body.
"Life', or the physical body part, is like a virtual reality game that the 'mind' part is playing, only every human is collectively part of the game. Just like a game, a 'save point' can be set, and the game continues, but if things do not go as expected, the player can reload the game as 'frozen' by the save point, and continue on. The player's mind, of course, remembers everything that happened the first time around, and can use that information to make modifications in her play so that this time around things will go differently. Except that, since it is a multi[player game, no one player can decide to go back to the save point. This option happens randomly, and beyond any player control.
Another difference is, the player's mind and the body are intricately linked, so the mind has no other body, and the body has no other mind (the game avatar is, in fact, part and parcel of the mind).
Another consideration is that the save point is always 24 hours (sort of like one 'turn'). You can not go back 48 hours, or 72 hours, or one week. Whatever happened up until 24 hours ago is unchangeable. It can not be redone. If you were falling off a cliff at the save point, you are falling at the same rate when the game is reset.
Another assumption - that the society has ALWAYS been this way, since 'creation', whatever form that takes.
Also, that everything physical gets reset - all of the laws of physics and all of the equations of physics, chemistry, and cosmology go back to exactly the same numbers, values, coordinates, states, that they were at reset. The physical body world is reset, but not the ephemeral mind part of the mind-body duality. The mind retains all of the experiences, memories, skills, wisdom. and knowledge gained.
**If my analogy and assumptions are correct, if this is your world, read on. If not, I suppose this answer can be deleted.**
In this scenario, a mistake that a person makes is not always final. If they mess up, there is a chance to re-play part of their life - one complete day's worth. But they can not depend on this. They can not plan on it happening. If they mess up, and the game gets reset to the last save, bonus for them. A second chance. If the game does not get reset, they are stuck with their decisions.
So if, for a crude example, one is married and decides to go on a hall pass, and has absolutely great mind-blowing sex with a stranger, but ends up with a communicable disease, if the day is reset they have the absolutely exquisite memory but not the consequences - they no longer have the disease. But they can not COUNT on the day being reset.
This happens even if something GOOD happens. That is, if they win a lottery and are set for life financially, and the day is reset, they can lose the lottery the next time around. Random chance is random, even between iterations.
**TL:DR**
The legal system by necessity would have to have as its basic tenet 'most recent most legal'. That is, the only thing that would be considered is the state of the world at the end of the latest iteration. Just like the end of a virtual reality game depends on the most current iteration, not on what happened in the iteration before the reset. You win or lose the game AT THE END, not in the middle. Some players that were winning, end up losing; some who were losing end up winning; but the only thing that matters is how the game ends.
There is no such thing as fair or unfair in life - things happen. Upsets happen. It gives, and it takes away. The only thing that really counts is how it is played out until the end, and the memories, skills, wisdom, knowledge, isight you gain along the way.
**EDIT**
Looked at from another angle, our legal system is based entirely on causality. We did something that caused something else to happen. Everything is sequential.
Consider the following argument in a court of law:
"You woke up this morning and you visited your ex-spouse, you got in an argument with her, and you killed her. You had great remorse for what you did. So when you got up this morning, you remembered the consequences of you going to see your ex-wife later in the day, and you decided not to visit her. So you did not kill her. So when you woke up this morning, the consequences of your actions later on in the day caused you to do something different in the past, so your wife is not dead."
Where is the chain of causality? The act of killing her lead to you not doing something that lead to you not killing her.
The only arguably legally pertinent 'causality' chain is the most recent one. You did not kill her, therefore you are not responsible for nor did you cause her death.
[Answer]
It's worth noting that in most depictions of a Groundhog Day loop (including the one in the eponymous film), only one or a small group of people can remember what happened. You seem to be assuming that everyone in the loop remembers, so I'll answer under that assumption (your world; your rules).
Starting with the last:
### Contracts
If a contract has physical requirements, including money, then the person has to make sure they are in compliance after the groundhog loop ends. Requiring compliance within the loop seems problematic, as it seems likely that people will get tired of repeating the same actions for no result.
The most natural thing might be to make groundhog days into business holidays. Because until the last day, the actions don't really count. Most contracts would explicitly handle issues like loops, because they would be expected. It would be natural to push out the deadline if a loop holiday prevented the delivery date.
The only event within the loop that would be controlled by contract would be those enforcing secrecy. A loop would not obviate the need to keep information private. Because information transfers are the only thing that can persist past the loop.
### Trials
The first day, they would have to hold the trial. Because they don't know that they'll loop (at least as I understand your rules). But I suspect that they would call it off for the remaining days of the loop. Because they wouldn't be able to keep any of the physical records from the day.
I suspect that you are correct that they would have to redo that first day. Yes, it may disrupt the trial. To reduce the impact of that, trials may concentrate more on affidavits and less on direct testimony. The reason being that it is easier to redo an affidavit than a cross examination.
### Erased crimes
It would make sense for property crimes to only count on the last day, when they actually take effect. Because that's the only day when someone actually loses the property. But violent crimes should be illegal whenever. Because the trauma from, for example, rape, is more mental than physical.
They may get prosecuted less, as it might be harder to gather evidence. But such crimes should stay criminal. And it's not like there aren't crimes prosecuted purely on witness testimony now. Such prosecutions are possible albeit more difficult.
] |
[Question]
[
**Closed**. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers.
---
**Want to improve this question?** Update the question so it focuses on one problem only by [editing this post](/posts/138143/edit).
Closed 4 years ago.
[Improve this question](/posts/138143/edit)
In my story, there is a war between humans and a slightly more advanced and clever species. The humans outnumber the other species and end up winning the war because the humans spread a virus to the species that wipes out even more of its population. The humans are the only ones that could develop a vaccine for the virus.
Humans and this species are very similar, but members of that species are larger, stronger, and more quick-thinking than humans. Individually, an educated member of that species could outsmart an equally educated human.
Humans have a slight advantage because they can reproduce faster and require a bit less resources than the other species. After winning the war, the humans are able to reverse engineer a lot of the tech from the other species.
Would humans be able to enslave a cleverer creature? How could they control this species enough to enslave its members? Would going through the trouble to enslave the species be economically worth it?
[Answer]
The numerical advantage the humans have at the end of the war allows for the establishment of a social order of slavery, and that's all that's really required. Individual differences of ability, on the ground, between slaves and masters aren't that important to the institution of slavery. After all, historically household slaves were often left to the direction of women and children who had no physical ability to impose their will on masses of slaves.
The slave must know that if he disobeys his master, he is subject to physical injury or death, and that this will be enforced (if necessary) by the society at large and by the police power. He must also know that in a dispute with his master he has no legal recourse. If those two things are true, the institution of slavery can be maintained, and the intelligence and strength of individual masters is of no consequence.
Highly intelligent and strong slaves would have an advantage in undertaking a system-wide revolution or slave rebellion, but those are relatively rare events - and harder to undertake against a well-organized and technologically advanced state. Slaves could rise in Haiti and win, because they had an overwhelming numerical advantage and because the masters had a very difficult logistical situation. Slave rebellions in the United States were much less successful. A slave rebellion against a "future tech" state would face a steep uphill climb.
[Answer]
The Aliens must have a weakness that makes the enslavement feasible. Something like the [Jotoki](https://en.wikipedia.org/wiki/Jotoki) from Larry Niven, who bond themselves to their Parents and when the Kzinti enslaved their former masters, the bond to the Kzin they see at first and have to obey them.
[Answer]
1. Numbers. We've done it in the past, we overwhelmed several Hominids to become the dominant species.
2. Divide and conquer. Get them fighting with/hating each other more than they hate the humans.
3. Treat them nice. The reason there were so few slave revolts in Rome was largely due to the fact that slaves had rights, could not be made to do certain things, were often paid, and could eventually buy their own freedom
4. The humans have the food. Bigger brains need more food, humans can take advantage
5. Propaganda. Drive it into their heads that they started the war, committed many atrocities, and the humans showed mercy in not killing them all.
] |
[Question]
[
Okay, so I have this binary planet system. The main planet a *bit* bigger than earth with a size appropriate moon-planet. Both are habitable and with a humanoid species that evolved there.
But, I know that the rotations of the planet are tidally locked as a result and a 'day' on the moon planet is much longer than the primary planet, about 27-29 days in earth days and a much heavier tide on both sides
On both planets, the natives are humanoid enough; requiring almost all basic things we do; oxygen, food, water, *sleep* etc... and a lot of vegetation— and accompanying wildlife (predator & prey).
**Question:**
Since the days are vastly longer on the moon-planet, how would that effect the wildlife and natives?
I'd assume 2 weeks in day and 2 weeks in night; if that's the case then It could make things easier to see.
Vegetation life would be good, the 2 weeks or so, the plant life would develop bio-luminescence (using the energy absorbed in the 2 weeks with sun) to keep itself alive.
**But my primary focus is on the humanoids.**
Would hibernation for 2 weeks be the more obvious choice for their physical wellbeing to deal with the long days. (I am aware humans cannot hibernate but other mammals do)
Or would they have to live 2 weeks in darkness and 2 weeks in light and use our sleeping pattern of 8 hours a sleep in a designated amount of time?
[Answer]
Sleep need is relative. Many animals don't need sleep at all, even more complex ones such as whales and dolphins.
Cetaceans can't really sleep or they will drown. So they just "shutdown" (actually, reduce or change activity) one hemisphere of their brain for some time everyday. Then they swap the "sleeping" hemisphere. During this time they just float around doing nothing intensive, but they are still awake. After that "whale rest" they'll have both hemispheres in gear again and will do whatever it is that they need to do.
Humanoids in your world that don't hibernate could do it like whales do, even if they are land dwellers.
They may also have eyes like the [ogre spider](https://en.wikipedia.org/wiki/Deinopidae):
>
> Its eyes are able to gather available light more efficiently than the eyes of cats and owls, and are able to do this despite the lack of a tapetum lucidum; instead, each night a large area of light sensitive membrane is manufactured within the eyes, and since arachnid eyes do not have irises, it is rapidly destroyed again at dawn.
>
>
>
With such prolonged days and nights, this mechanism to change the way the eye works from day ti night could evolve to be even more efricient than the ogre spider's.
[Answer]
Perhaps the humanoid species has diverged into two subspecies (or modes!): one is nocturnal, and the other is diurnal. The two have a symbiotic (and perhaps interfertile) relationship. During the day-month, the diurnals manage things. During the night-month, the nocturnals take over.
This dual-benefit-ism could form a very strong part of their psyche. It would also form a rather important kind of trust between the two groups, since a group that acted selfishly against the other would essentially destroy the whole. I can hear fables or parables being told about this world-wide.
So as not to be boring about it, I would assume that each species or order (or phyla...) would have solved that problem in DIFFERENT ways. So if you don't like the sophonts being dualist, perhaps an order of "regular" animal does it this way.
] |
[Question]
[
Imagine a civilization capable of interstellar travel and building Dyson structures, so technological advancement and energy acquisition are not a concern.
They found a planet that is very Earth like. And by Earth-like I mean it orbits a star similar to the sun, with an orbit similar to Earth's. It has the same axial tilt, and even has a hurricane belt of its own around the same latitudes on its northern hemisphere. On that belt sits some resource the hypothetical civilization wishes to extact.
There is intelligent life on the area where the unobtanium is, though, so they wish to relocate the natives. The engineers have come to the conclusion that while land or air vehicles could help move a few millions of locals within a few months, a hurricane could do the job in less than a week, and with much less lip.
How could such a civilization kickstart a really strong hurricane?
[Answer]
While I question the reasoning for using nature as a tool for evacuating the inhabitants (Are you saying that your colony will not interact with the inhabitants at all?), I guess it's better than military might and wiping them all out.
There are a lot of factors when it comes to forming hurricanes, however one biggest common requirement is water temperature. Most if not all hurricanes require warm water temperature to start growing.
One can beam microwave energy onto the hurricane belt to sufficiently warm the water from space. Do this long enough so that the warm water reaches the deeper parts of the ocean and prevent cooler water from circulating, and this will fuel the hurricane long enough to grow into an F5, probably stronger if everything works as "intended". Guiding the hurricane however, is another matter entirely.
I'm sure other people that has better understanding of hurricane formations will answer your question more effectively, but I believe that simply heating up the ocean can create a powerful hurricane.
] |
[Question]
[
Here's some rough WIP pixel art of the planet I'm trying to create just to give you an idea of what I'm talking about color wise. I'm referencing the dark blue that you see at the poles of the planet.
[](https://i.stack.imgur.com/SMjBk.png)
.
This planet is going to be similar to Neptune in a lot of ways, a little smaller, about twice as massive, and also in the cold outer solar system, but I'm not sure if methane would be able to create the deep, dark blue color in the atmosphere that I'm looking for. Maybe nitrogen or oxygen or some compound with those? Or some completely different chemical?
[Answer]
**Tiny swirling methane crystals.**
<https://www.universetoday.com/21591/color-of-neptune/>
[](https://i.stack.imgur.com/3Bddb.jpg)
<https://solarsystem.nasa.gov/planets/neptune/in-depth/>
Neptune is really blue.
>
> Neptune's atmosphere is made up mostly of hydrogen and helium with
> just a little bit of methane. Neptune's neighbor Uranus is a
> blue-green color due to such atmospheric methane, but Neptune is a
> more vivid, brighter blue, so there must be an unknown component that
> causes the more intense color.
>
>
>
I can think of two ways to make something like Neptune blue. One is more methane, that absorbs red and reflects blue. The other is Rayleigh scattering. The shorter the wavelength of light, the more likely it is to bounce off of something and keep going in a different direction. That is why the sky is blue - short wavelengths like blue bounce off of stuff in the sky, possibly back down to our eyes while longer wavelengths get absorbed or keep on going. That is why colors drop out with ocean depth - first reds, then greens, with deep blue (and presumably ultraviolet) the last light to disappear - because these rays have bounced and scattered their way downward as other frequencies were absorbed.
If your atmosphere were very full of tiny swirling methane crystals they could serve double duty - absorbing reds and scattering blue and violet back out. I bet that is why Neptune is so blue and I bet that is the secret of Uranus' newly discovered blue ring.
] |
[Question]
[
The problem is that I would like to know how strong the creature I have in mind will end up being and if that would be *too strong*. I know that 15th century plate armor was very good against slashing weapons and that swords would be the last thing one would like to use against an armored opponent, which is why I'm having a hard time getting a clear idea of how much force it would require.
**The Scenario:**
A Humanoid man-made life form enhanced by some of the most advanced magic to enhance it's strength for a short period of time is capable of slicing in half a soldier clad in full-body steel plate.
The creature is aproximately 8 ft tall, 425 pounds and is using a 2.5 meters long [Zweihänder](https://en.wikipedia.org/wiki/Zweih%C3%A4nder) which weights about 7.5 kg total.
Skirting around the issue of the sword possibly breaking and how implausible it would seem to cut cleanly and instantly through steel plate in such a fashion, *how strong would that creature have to be to achieve such a feat in comparison to a normal human*? Or the strongest human, even.
[Answer]
For starters, a zweihander was actually more of a thrusting weapon than a cutting weapon, used more like a spear than a sword for the most part, unless the wielder was out of formation in a looting situation. If you look at the martial art manuals for zweihander use, you'll see that their wielders - at least those that survived more than one or two battles - fenced with them rather than winding up to deliver king hits. Their advantage over a regular sword was their length and leverage, with their users hands a couple of feet apart (one grasping the hilt, the other grasping the blunt part of the blade behind the thrust-stop spikes), they could push through a single-handed weapon parry, not with momentum, but with leverage.
So, I can't imagine a professional *landsknecht* swinging his zweihander around for any purpose other than to frighten non-soldiers.
Secondly, being a largely thrusting weapon, a zweihander is likely to be none too sharp, as the OP has stated. Sharpness is effectively a pressure multiplier. If the wielder of an edged weapon applies a force, F to the hilt of his weapon over a surface area, A1, and applies that force via the edge of that weapon to a target, then the force F is applied over a smaller area, A2. Since pressure is force divided by area, pressure, P at the edge of the weapon is (naively):
P = (F x A2)/(A1^2)
Obviously, minimising A2, by sharpening, allows a higher pressure to be applied. Zweihanders achieve this not so much by having a sharp edge, but by having a sharp point, which is easier to make small than a long edge.
Of course, since weapons are swung or thrust from some point distant from their intended target, the force applied to the target via the edge/point is dependent upon the force the wielder applies to the weapon over the time that the weapon is swung prior to and during impact. The blow then becomes a question of impact energy.
So, if the OP's homunculus is to swing a zweihander (against all common sense, unless it is immune or higly resistant to potential counterattacks) and cleave a fully armoured soldier in two, then a number of factors come into play:
1. Unless the zweihander has been sharpened to a degree more akin to the sharpness of a scalpel or a Japanese samurai's katana, this will mean that a higher amount of input force will be required.
2. Oiling or greasing the blade - or potentially even plating it with lead - will assist by reducing the friction between the blade and the cut edges of the opponent's armour.
3. Plate armour came in several grades, from thin and even rusty iron or mild steel, to thick high-carbon steel proofed against bullets. The latter obviously being far more expensive than the former, with many variations in between. A 'fully plate armoured opponent' may have been wearing thin mild steel that a blow from a merely human opponent could be expected to penetrate if delivered with strength and skill by a sharp pointed weapon, or they may have been wearing thick, high-carbon steel siege plate, against which almost any blow could be expected to be more likely to knock the wearer down than to penetrate. We will assume cheap, thin mild steel plate armour that has suffered from rust during its career, and is now effectively thinner than originally manufactured, even if it is now polished.
4. The capabilities of the wielder of the zweihander now come into play. Being big and muscular helps in applying force to the hilt of the zweihander, but being big and strong is not all there is to it. Muscles can only contract so fast, and the closer they approach their maximum contraction speed, tbe less force they can apply. Animals achieve high strength by greater leverage - a higher joint-to-muscle-length to limb-length ratio, and achieve speed by making this ratio smaller. Both can be achieved by having big muscles and a small joint-to-muscle-length to limb-length ratio. If magically enhanced, the big muscles may contract faster and more forcefully than usual too.
5. The technique with which the blow is delivered also plays a part. By "winding up" for the blow, bringing the zweihander around behind the wielder's body and then delivering the blow by applying muscular force not only from the arms, but also the waist and hips, the greatest force can be applied to the hilt of the weapon over the greatest time, resulting in a higher velocity.
6. The grip the wielder of the zweihander has on the ground also plays a part. Apply more force to the blade than the grip between the wielder's feet and the ground can take, and the wielder's feet will slip, reducing the overall force over time applied to the blade.
7. Just where the victim of the blow is hit will affect the blow's effectiveness. Obviously, a hit to the abdomen, with the blade passing through one of the intervertebral disks rather than bone, and the blade also hitting the armour at a joint so that the metal need be less cut than merely bent out of the way would make the end result easier to achieve. This would be best achieved with the attacker's shoulders level with the victim's waist given the typical design of plate armour waist articulation.
8. Obviously, the victim failing to block or parry the blow is very important. Perhaps they are engaged with multiple foes, or have dropped their weapons, or are simply caught off-guard.
So, to ask "how much stronger" obviously depends on all these factors, and can't be answered naively. However, assuming that all else is optimal, the wielder would not need to be greatly stronger than a very strong human, and as other factors become less optimal, the strength required increases to the point where it is impractically high.
To *attempt* to give a naive figure, if all else is optimal, perhaps twice as strong as a dedicated bodybuilder would be the right figure, but the creation would also be faster and heavier, and may even have clawed feet.
Whether or not the zweihander survives unbroken during this event would be dependent upon the negative factors I have already mentioned, as well as the quality of its metallurgy, construction and its sharpness being points in its favor.
I base this on historical records of merely mortal samurai cutting unarmoured prisoners in two at pretty much every place and angle imaginable, the most difficult successful cut being recorded on the blade as proof of its quality. Famously, one prisoner, being informed that he was to be executed by a cut at waist level, rather than exhibiting fear, quipped that he wished that he had been given more notice, so that he could have swallowed rocks that would have chipped the samurai's precious blade.
Additionally, Japanese records of no-dachi wielding samurai in battle record said samurai cutting horses in two through the body on occasion, the no-dachi being an oversized curved sword like a katana that were in actuality used in the manner that it is only imagined that zweihanders were used.
[Answer]
Turn your sword from a slashing weapon (like a katana) to a chopping weapon (a grand shamsheer, perhaps, with a lot of mass in the tip and a more axe-like edge contour) and it ought not to take even superhuman strength to make the cut you describe. Get a good swing (say, blade velocity around 30 m/s, about like a good fastball, well under the club head speed of a professional golfer), and a blade weighing 3-4 kg can readily cleave through plate light enough for the wearer to walk around -- along with the body inside.
Cutting through the abdomen, FWIW, is easier than cutting the legs or ribs -- much less bone in cutting one vertebra, than in cutting a femur, multiple ribs, or even a single humerus.
Now, your cutter will be taking a "mighty swing" to do this, so he'll leave himself open for stop hits, but if the victim is busy cowering instead of trying to kill as he dies, he'll fall just the same.
[Answer]
I am afraid no amount of strength will really help; only a radically different construction of the "sword" can do anything to it.
The main point is that the sword is stopped by the dense matter it is cutting through. The depth it can reach is determined by the densities of the sword and the matter it cuts, and by the width of the sword blade. To cut through iron (or steel) that has approximately the same density as the sword, you need a rather large blade; as mentioned in the answer of @ZeissIkon an axe-shape weapon will be better for this purpose.
] |
[Question]
[
Recently I have read about radioteletype devices capable of sending text messages via radio waves already in the first half of 20th century. Unfortunately, these teletypes used Baudot code, which is too limited for my needs. Ideally, I would like to have robust, wireless text transmission over large distances using at least 256-character encoding, including control signals (no transistors allowed, just vacuum tubes).
Initially I thought that devices should use QAM, since it allows to send multiple "bits" in one signal, but I fear 256-QAM would be too difficult for simple electronics of the era. Is it so? Would it be possible to build 256-QAM equipment in 1940s/1950s? If not, what other technology can I use?
I am specifically asking about the possibility of developing enhanced radioteletypes capable of being deployed in vehicles like trucks, ships of aircraft, not about some experimental equipment working only in lab conditions.
[Answer]
ENIAC was started up (in secret) in 1946 -- a programmable digital computer built entirely with vacuum tubes. It was an advance on previously existing electromechanical (relay-based) computing machines mainly in terms of speed, being around 100 times faster.
Those earlier relay-based digital computers, as much so as ENIAC, with limits on transmission rate, had the capability (had anyone seen the need to replace Baudot coded teletype) to handle a serial data stream, capable of transmitting any desired data (as it was, many years later, when computers began to communicate via modem on analog telephone lines).
To provide more available characters (as to handle multiple language text, arbitrary bitmap images, etc.), one merely needs to increase word length. Baudot was a 5-bit system; originally, ASCII was 7-bit, expanded to 8-bit around the time microcomputers appeared. The difference is protocol, not hardware technology -- if your transmission system can send one bit wide serial data, any arbitrary encoding length is just a matter of the protocol the machines at the sending and receiving end use.
] |
[Question]
[
I am trying to describe consciousness from a magic elementalist perspective. I've dug through a ridiculous amount of pages of occult alchemical lore without success. My goal is to learn if students and/or practitioners described the human soul/consciousness with respect to elemental energies.
My world has many tie-ins to the occult and alchemical genres, and so I am trying to define the soul with respect to them. **My question is: in the logic of alchemical practice, what reasonably associates/describes human decision making concepts with elemental attributes?**
Clarification: I am looking for some existing thought(references) that attempts to roadmap this out.
[Answer]
## Theoretic
Alchemy is a soteriological practice, a means by which we attain salvation. Decision making is centered around the alchemical logic of elemental energies that are conducive or not conducive to achieving union with one's full potential; through transmutation of the soul to a higher paradigm of consciousness into a new mode of being wherein you mesh with the deeper, humbling and all-pervading true alchemical "gold".
The alchemical element most strongly associated with consciousness, is aether, void or quintessence. Aether permeates all matter, but rather than providing a medium through which light travels or the basis for alchemical medicine as with medieval quintessence, aether is more properly conceived as the instantiation of mind in any information-bearing system. That is, even a rock or a thermometer, to borrow from philosopher David Chalmer's panpsychism, can be said to be conscious (or participating in mind / aether) to differing degrees.
Thus the logic of alchemical practice is driven by combination of aether/void with the fire, earth, air and water elementals (perhaps these could be represented as personality traits, specific virtues or general approaches/schools addressing the alchemical praxis of mind). The aim, as above, is soteriological, to transmute phenomenological existence itself to an expanded plane of awareness wherein one can be said to have dissolved into the universal aether.
## Alchemical lore
Zosimos of Panopolis was a late 3rd century AD Gnostic alchemist from Roman Egypt. The *[Visions of Zosimos](https://www.tandfonline.com/doi/abs/10.1179/amb.1937.1.1.88?journalCode=yamb20)* wrote:
>
> There are two sciences and two wisdoms, that of the Egyptians and that
> of the Hebrews, which latter is confirmed by divine justice. The
> science and wisdom of the most excellent dominate the one and the
> other. Both originate in olden times. Their origin is without a king,
> autonomous and immaterial; it is not concerned with material and
> corruptible bodies, it operates, without submitting to strange
> influences, supported by prayer and divine grace.
>
>
> The symbol of chemistry is drawn from the creation by its adepts, who
> cleanse and save the divine soul bound in the elements, and who free
> the divine spirit from its mixture with the flesh.
>
>
> As the sun is, so to speak, a flower of the fire and (simultaneously)
> the heavenly sun, the right eye of the world, so copper when it
> blooms—that is when it takes the color of gold, through
> purification—becomes a terrestrial sun, which is king of the earth, as
> the sun is king of heaven.
>
>
>
In your world, alchemy of mind is a contemplative/meditative practice where the alchemical vessel is imagined as Zosimos did; a visualised baptismal font where elemental tinctures combine as purifying divine waters of Hellenistic alchemy, transmuting and perfecting the Gnostic initiate into Godhead.
This would also be consistent with Jung's take on Zosimos alchemical treatises as allegories of self-destruction and rebirth, which [Antonio D'Alonzo](http://www.esonet.com/News-file-print-sid-463.html) explains a lot better than I:
>
> Jung gives a lot of space to Paracelsus' writings, to the ‘Mercury
> spirit' and to the symbolism of the tree. But the main figure at the
> center of Jungian interest is Zosimos of Panopolis (III-IV A.D.). Jung
> was fascinated by Zosimos' treaties because of their visionary
> features, the oneiric projections on the objectivity of the matter,
> perceived by alchemists as intrinsic substantiality and not as a mere
> result of the dynamics of the unconscious process of individuation. In
> the Mysterium Coniunctionis , the last work before his death, Jung
> seems to realize that the dialectic integration of the fourth term –
> matter – in the divine Trinitarian scheme expresses symbolically the
> Whole, yet it doesn't realize it concretely and only mentions its
> possibility. The concretization of the alchemic work is given only by
> the effective, viz. spiritual, unification between man and cosmos (
> Unus Mundus , according to Dornean terminology). At the end Jung, in
> his constructive approach to alchemy, abandons the idea of overcoming
> the doctrinal boundary between the reassuring shore of
> psycho-analytical interpretation and the obscure karstic streams of
> initiatory operations. Despite his enormous erudition in the subject,
> he remains a psychologist, miles away from the followers of
> contemporary neo-gnosis. The task to widen the epistemological horizon
> of the Jungian research on alchemy has been carried on by two
> followers of his work, Marie Luise von Franz and Robert Grinell. The
> former connects the Jungian elaborations on the alchemic coniunction
> to the theory of synchronicity, referring to the heritage of the
> classic esoteric doctrine of micro-macrocosm, viz. the anthropo-cosmic
> dimension of the Whole. Grinell, on the other hand, focuses on the
> ‘alchemic' re-elaboration of the psychoid processes, defined as
> indissoluble interactions between spirit and matter; he excludes
> completely the possibility of a unilateral reading that doesn't take
> into consideration the coniuctio of the two words.
>
>
>
[Answer]
If you are trying to define the mind in terms of water, air, fire and dirt, you aren't going to find anything better than the Insane Clown Posse videoclip for their song *Miracles*.
When alchemists used those elements' names to describe things in nature, it was an arbitrary choice. They could as well have used words like Thingamajib, Watchacallit, Wossname and Foobar.
Alchemists' elemental vocabulary is more elaborate than that, though. If you wish to describe the mind, use terms that are appropriate for the mind.
The human mind, like anything else in the universe, is a manifestation of Kia. There is little point in elaborating further what it is made of - rather, it is more useful to discuss where it is, or how and to what it is attuned at a given moment.
Peter J. Carroll elaborates in this in his book *Liber Null & Psychonaut*, in the section about the Alphabet of Desire.
These are the "elements" of the mind, from an emotional analysis point of view. Notice that this is a very poor analogy - proper explanation would be bigger than Carroll's book itself.
The upper six are the proper "elements". Consider the lower four as "modes".
From these symbols and a load of other alchemist symbols, many emotions, such as joy, releade, anger etc. are conveniently placed in a diagram:
The chaos ball at the center represents pure laughter.
An alchemist/psychonaut's work involves navigating through those emotions for various effects. For further reaeing, also consider Phil Hine's *Condensed Chaos* for an explanation on how this connects your mind to magic. Again, the proper explanation is as large as the book itself. Have a good read.
[Answer]
One approach I have seen is that the human spirit *is* that which cannot be broken down, after all else has been dissolved. It *is* the thing which breaks the patterns of alchemy. That is how the Chinese concept of shen has been described to me. It is the human spirit that cannot be further divided.
A soul may appear to have elements of fire, or elements of metal, or whatnot, but it cannot be broken apart to reveal just the distilled fire or just the refined metal.
As for the best way to associate human decision making to your alchemy system, it depends on the alchemy system, of course. Personally, I find the [Wu Xing](https://en.wikipedia.org/wiki/Wu_Xing) (the Five Elements) from Chinese philosophy are very effective at breaking down the way humans make decisions and assigning elements to them. However, their system is rather different from the Four Element system which is common in Western alchemy.
By request, I can dig into how I think Wu Xing fits. Wu Xing is a *very* effective pattern to apply to many things, other than just thought processes. Accordingly it is very abstract. I adapted it to decision making to support a software development team I was part of at work. We had a customer whose needs changed so fluidly that not even agile techniques like Scrum could keep up. It was just the nature of the beast. Rather than try to force our customer to follow our approach, we developed this Wu Xing software development model. We found that the five elements of the Wu Xing are so intuitive that if we used them, our customer started to move in lockstep with us without us forcing them in any way. It just became the natural way to do business.
This is what we came up with:
[](https://i.stack.imgur.com/QtvP4.png)
The human thought process naturally flows around the outside circle.
* In the planning phase (water), the goal is to bring the energy levels down as low as possible. You want to be able to get a clear crisp view of what you are about to do before you put energy into it. When you are ready, seeds germinate and you enter...
* The Growing phase (wood). Growing is your exploratory phase. You brainstorm in all sorts of directions all at once. You know what you goal is, but not where nor how to achieve it. This process continues until you downselect to...
* One thought worth pursuing (fire). This is where you go off and implement things. The Chinese considered this to be an "upward" energy, like flames racing up a rope. The primary charactaristic of fire here is that it *will* burn itself out when it runs out of fuel, so it races along the path set forth in the growing phase. When it does, you enter....
* Stabilizing (earth). In this phase, harmony is the name of the game. You're trying to bring everything into alignment gently. I've been watching too many baking shows, so I think of it like folding chocoalate into whipped egg white foam. You have to be gently. If you beat the chocolate into the foam (such as with a powered mixer), you'll pop all the air bubbles and you wont have a foam left. You have to listen to the environment, and make the product of your firey phase fit. Once that harmony is there, you can...
* Stabilize (metal). This is the codificaiton phase. This is where you can do things like write specifications or iron out unit tests, or simply put words to the ideas you already had. When this step is done, you're ready to plan the next phase (water).
So, by this system, human thought consists of constantly walking around this cycle, developing ideas.
What made the system so fascinating to us is the interacting or "controlling" connections. What happens when *two* people interact using these patterns? Well it turns out there's some well defined behaviors that reach across the five elements. Water controls fire, fire controls metal, metal controls wood, wood controls earth, and earth controls water. We encouraged the correct interactions with the small words that appear next to each dashed line.
The beautiful pattern that forms is known as the grandfather/son relationship. To demonstrate it, let's start with a "hot" idea that's burning you up, and you have the idea that you need to gain control of it before it destroys you. Accordingly:
* The original idea starts in the fire phase. You choose to start your new idea in the water phase, because water controls fire. The fire is going to go in the direction it will go. Think fighting forest fires. Rather than going after the fire directly, you go after its fuel, dousing it strategically to shape the fire. At some point this will force the original idea to try to harmonize with this environment, as its fuel is gone (original: fire->earth)
* Now the relationship is reversed! Now the original idea is in the controlling position over the new idea (earth controls water). Now it can create dams and flows and shape the movement of the water. This can happen until you can no longer just sit still in the water phase, and need to generate new ideas to incorporate this harmonious position. (new: water->wood)
* Now our new idea is back in control. It can generate so many new brainstorms that there's no way they can reach harmony. This forces the old idea to switch to metal to pen those ideas in a strong solid form (original: earth->metal).
* Now the old idea is back in control again. It can garden and prune the brainstorm of the new idea until there is only one natural path, transitioning to fire. (new: wood->fire).
* Now the new idea is the thing that's burning. It melts and shapes the codified ideas of the original idea like a blacksmith with a hammer. Soon the shaping is complete enough that the original idea has to plan how its going to do its next step. (original: metal->water)
* ... now we have the same relationship we started with, except the roles are reversed. We can repeat this as long as needed.
What we found is that if you follow this pattern, the result is so easy to follow that people subconsciously tend to align themselves in this grandfater/son pattern. Thus, as far as "human decision making" goes, it should be an awefully useful pattern!
[Answer]
The point of this is explaining a soul with just elements. Am I right? If not pls write quick in the comments.
**The Soul** is something not 'existing'. You cannot touch nor prove it's there. After all it's just a theorie that we have a soul (Maybe even in your world). The Soul isn't something made of elements of mass like earth, water or air. The only thing, that comes close is **Energy**.
Pure Energy is also not 'existing'. It's in the element fire (A fire is energy) and lightning (if that's a seperate element from fire).
You could say fire and lightning is energy in a form (heat and electric energy) and you need special abilities to clean or purify energy and build with that a soul or change one.
You could say pure energy is like a block and a soul is a block puzzle or a electrical diagram. Or you could say pure energy is like a colorful slime and the soul is a ball with a great lightshow.
I hope this helps or brings up new ideas :)
PS: If you explain it like that narrative nonsense, like 'the fire of the soul' gets a context.
PPS: You could also say that magic power is generated by your soul and if you overdue, you lose your mind and memories, or just die, or just loose your soul so you cannot use magic again. Thats up to your fantasy
] |
[Question]
[
My world is a medieval-magical setting like in "The Dark Eye".
An extinct, magical elves-race had a technique to raise "bugs" from sand, but other materials were possible too. Those bugs usually had a maximum size of about 20 inches, depending on the work they were created for, obeyed **all** commands of their creator and needed a small amount of mana to stay "alive" (a normal Elf produced enough mana to maintain about 3 of those big bugs, more if they're smaller).
Usually, they did nothing, if they didn't follow a command. But those bugs are not dumb - they just did nothing, because they couldn't! The elves
subconsciously disallowed unordered actions. As the elven race distincted, the bugs did so too, but one elf was magically turned to stone, and awoke thousands of years after his folks died. His 5 bugs are still "alive", because they drained him all the time. He ordered them to create more of themselves, unluckily he didn't notice that some bugs aren't following his orders (his subconscious couldn't surpress so many bugs).
Why should those indepent bugs multiply themselves?
[Answer]
Perhaps the "personal mana" of the elf is actually a "racial mana" which just before his petrification was spread out across all living elves. Now as the last surviving member of his race, he contains all the elven mana, thousands or even millions of times what he originally possessed. Unaware of this significant power upgrade, he dedicates all of his mana to the bug replication command, with a exponentially expanded results.
And maybe the enormous flow of mana involved has overtaxed magical muscles, leaving him too spent to further manipulate or command his army of bugs.
[Answer]
You should really watch a short movie from Disney called The Sorcerer's Apprentice, about disobedient magical servitors.
[Magic is like programming](https://worldbuilding.stackexchange.com/a/116286/21222). Magic that is about giving commands to artificial beings is doubly so.
Analyze the logic of the alghoritm:
```
Step 1: reproduce
Step 2: repeat step 1
```
See what the wizard did there?
As for why the bugs are doing whatever - thwy may have picked up orders from anyone or anything during the millenia the wizard spent as a rock. Heck, if I find a functioning drone abandoned in the middle of nowhere I will have a go at playing with it. Reminds me of the opening scene of Interstellar where the protagonist does exactly that.
I once programmed a whole network of computers into playing a UI-less coop clone of Progress Quest of my own creation, just for kicks and because I am an idiot. Who knows? Maybe your mage wakes up one day to find that he is standing on a humongous [Manacoin](https://worldbuilding.stackexchange.com/a/112321/21222) mining farm.
] |
[Question]
[
I'm writing the last issue of my comic and I'm in trouble. My villain is a member of a cosmic cult that wants to absorb everything in the universe to create a conceptual/energy pangea out of space and time. In other words, the *big boss* is part of the universe itself and is trying to collapse the rest into himself to return to a pre-big bang state.
**To conquer planets and citizens the cult send a member to "plant" an obelisk that will absorb matter around itself and convert it to pure energy**. Now, the question:
Presuming that the cult has every kind of power, how would the absorb process take place? In a movie, I would make the matter simply disappear but in a comic, I need something different, so I'm asking you how the process could happen in a pseudo-scientific way. Then I'll think about how to draw it.
PS: I'm lurking a lot and that's my first question, I'm kinda excited, you're an awesome community!
**EDIT 1**
I did not explained it well because it is very long and complex, also metaphorical. It's a kind of "need to be one together" again with the universe, but that's not the point.
The obelisk will absorb the matter around itself, collapsing it into the big boss through the energy/mental connection that he has with the obelisk itself. I need a visual explanation more than a scientific one. I know how the physics works in my universe, I don't know how to conceptualize it onto drawings, so I asked for a scientific suggestion that would help me to visualize the process.
[Answer]
Some theories foresee that your supervillains don't actually have to do anything to revert the universe to a pre big-bang state: [the big crunch](https://en.wikipedia.org/wiki/Big_Crunch).
Are they trying to speed up the process?
What's "pure energy"? Heat? I doubt it... Electromagnetic radiation? I guess this is better.
Since Einstein's $E=mc^2$ is quite easy to convert mass into energy and, with a "simple" neutron gun/emitter they can just make nucleus of atoms split, releasing energy as we usually do in our [nuclear fission](https://en.wikipedia.org/wiki/Nuclear_fission) power plant.
We are not space travelling supervillains, therefore we managed to reach nuclear fission only with few pesky materials like uranium-235, but a cult with "every kind of power" is for sure capable to use most part of the periodic table.
In any case their actions won't actually help to revert the universe in a pre big-bang state, at the opposite they are delaying it by removing mass.
If they want a big crunch they should do the opposite: harvest energy from everywhere and convert it in a solid block at the center of the universe.
[Answer]
I tried leaving a comment to clarify some things about how these obelisks work but I'm also new here and I don't have that power yet. So I'm gonna go ahead and suppose some things about your comic. Feel free to correct whatever I got wrong.
## A few assumptions about your universe
Since you mentioned pseudoscience I'm going to start with the fact that the universe is infinte and in expansion. With that in mind, I questioned your statement that the obelisks absorb the matter around them.
How many obelisks would it take to absorb the entire matter of the expanding universe? I'm thinking either a few (and by few I'm probably talking millions) with enormous absorbing capacity or a lot (go figure this amount) with little capacity. Maybe even both, which would be a more accurate narrative element.
Once you solve the issue of the absorbing ratio, there's the problem of the perception of the obelisks by the people it affects. Is this gradual or aggressive? Suppose you place an obelisk on Earth. How do humans perceive the space being sucked around them? Is it like a vortex or black hole from which nothing can escape from? Or things just vanish as time passes and no one really pays much attention until its too late?
## The "Agressive" Approach
I would use this one if you assume that every obelisk has a gigantic absorption ratio. You could draw an obelisk as a tremendous anomaly in space that could be perceived parsecs away, like a black hole, a pulsar or even a supernova. Maybe the obelisks manifest diferently throughout the space, since the cult members place them in different locations.
They could also manifest themselves in a way that defies the laws of physics. Maybe a seed planted into a certain sun would alter the orbits of the planets in a given galaxy, making them stray further away from the sun insted of closer. This approach would be great for explaining why he was able to seed so many obelisks before someone noticed - cause even though the changes are drastic (catastrophic, even), someone has to be paying attention to notice them.
## The "Gradual" Approach
This approach probably works best in a narrative where the obelisks have to be placed in planets.
Here you would have to show the absorption from the point of view of the inhabitants of the planets. Maybe some people would start losing their memories. Some buildings could start to vanish. People would lose the ability to feel emotions or anything at all. Species could start being extinct out of the blue. And maybe the obelisks have some kind of mechanism that prevents intelligent life from noticing it, so you could show some analogy of rats fleeing the ship while the humans (thinking of an Earth-like scenario) are completely oblivious of their imminent doom.
Another plausible way to picture the obelisks' action would be an increase in natural disasters around the globe, cased due to a significant shriking in the planet's mass (or some science bs explanation like this). Cataclysmic events would start being more and more frequent to a point where the planet would eventually collapse and end all life after crumbling on its own ([Sunshine](https://www.imdb.com/title/tt0448134/) is a good movie to picture the early stages of this, while [2012](https://www.imdb.com/title/tt1190080/) would be a way to picture a planet close to its final destination).
---
Either way, I think it's a cool move to make every obelisk different. Again, I'm taking a lot of freedom with your story here, but why not make every member of the cult attached to one of these obelisks? Maybe they draw a small bit of the energy sucked by the obelisks for themselves, which would make them formidable foes and also give the heroes a geographical way to locate the cultists.
Find the obelisks, find the cultists.
This way, a stronger obelisk would mean an even more terrible foe, until the heroes eventually get to the part-of-the-universe-entity ultimate boss. You said nothing about this guy. And I'm really curious about HIS design. I'm thinking maybe something in the Azathoth neighborhood?
Hope this helped in anything.
[Answer]
Since you're looking for a comic-book themed visualization, the closest that I can come up with are sinks draining and black holes.
If the obelisk were an object that just absorbed everything that touched it, I would imagine the planet's atmosphere going first, with high speed winds pushing dust and debris along with it. Spiraling bands of clouds would appear in the troposphere, as this is going to produce one huge low pressure zone, and I'd expect to see a huge eye wall cloud, on the scale of the largest hurricanes.
And yes, it would all be swirling because of conservation of angular momentum. The atmosphere would try to form an accretion disk as pressure from the rest of the atmosphere pushes more air and debris into the obelisk.
Eventually the atmosphere would be gone, with the oceans boiling away, and any ice that reaches the melting point just sublimating away instead. At this point, nothing much would happen unless/until the obelisk switches to a more active state, either gathering the planet's material through some unknown force or simply digging straight down. (Our heroes wouldn't ever see this point, of course... but a "lone survivor" from a previously devoured planet can describe the process quite well, and would likely have video of the event from their ship's sensors or even just their planet's equivalent of a smartphone, so I feel it's worth describing further.)
Either way, once it breaks through the crust and into the mantle, gravity does the rest. As the obelisk eats through the molten material, there's nothing left to support the crust above, which will fall inward making the mother of all sinkholes. The sinkhole will get larger and larger, as less of the mantle exists to support the crust. Since the molten rock will be flowing towards the obelisk, the continental plates above will split at the plate boundaries and major fault lines, with the surface of the planet being torn apart, exposing glowing hot mantle to the surface of the planet all around that planet.
Eventually (since the matter/energy is being siphoned off to the universe eater itself, and not being stored in the obelisk), there won't be enough mass around to keep the remnants of the planet pressed up against the dangerous parts of the obelisk. Unless the obelisk goes into another active phase to suck up the rest of these bits, you'll be left with a huge debris and dust field orbiting the star where your planet once was. (Eating planets and stars is messy... Just ask any black hole.)
] |
[Question]
[
This is my first question so any feedback is appreciated! I basically have an Earth analog that has an axial tilt of approximately 12 degrees instead of Earth's 23, and I wanted to find out how I could approximate the length of the longer polar nights the flora and fauna would be subjected too. Thanks!
Edit: I would also like to know how I could approximate how much of the planet would be affected by this polar night, as in what latitude to the pole would the polar night cover.
[Answer]
Axial tilt doesn't matter. The longest polar night will still be half a year, as will the longest polar day. Those happen only exactly at the poles, though. The length of the longest polar day or night decreases from the pole to the polar circle (at 78 degrees latitude in your story), where there is exactly one day (at the summer solstice) and, half a year later, one night (at the winter solstice) longer than a full solar day.
[](https://www.flickr.com/photos/alexpanoiu/41245555060/sizes/o/)
*The relationship between the axial tilt angle $\theta$ and the latitude of the polar circle, $90^{\circ} - \theta$. The planet is shown at the summer solstice. Own work, available on Flickr under the CC BY-2.0 license.*
As shown in the picture, the pole stays in the light for one half the year, and then will go into the shadow for the next half. A point exactly on the polar circle, at a latitude equal to 90° minus the angle of axial tilt, on the day of the summer solstice will remain in the light for one full rotation; the daytime will be almost three full solar days. Any point between the northern and the southern polar circles will never experience a day or a night longer than one full solar day; but, of course, near the polar circle the night time (or the day time) can be very brief. For example, on our Earth, [Leningrad](https://en.wikipedia.org/wiki/Saint_Petersburg) is famous for its [white nights](https://en.wikipedia.org/wiki/White_Nights_Festival).
] |
[Question]
[
Question: many SF stories (e.g. The Expanse) put living organisms in highly radioactive environments and show them consuming that energy in some way. How might organisms put into these environments be able to harness this freely available form of energy?
My background isn't biology so I don't know the whole answer but I know enough about radiation that I would assume the best candidates would be beta and alpha particles of lower energy. However, I'd like the answer to include discussions of other radiation forms:
1. Alpha (Helium nuclei)
2. Beta (electron)
3. Gamma (high energy photon)
4. proton (e.g. from solar wind)
5. neutron (typically from reactors)
6. fission products (high energy positively charged nuclei formed by splitting
large nuclei)
7. other (anything else you care to discuss such as antimatter, positrons, x-rays, cosmic rays, etc.)
[Answer]
Some breeds of fungi are radiotrophic, metabolizing radiation. Mycologist Paul Stamets discusses them a lot in the context of depollution and forest remediation with various types of fungus. I'm not sure how this breaks down according to the hierarchy you presented, but apparently it works for decontamination of radioactive sites.
] |
[Question]
[
I am currently working on a world with a "human" species. The planet is similar to ours and these "humans" would evolve in a similar environment.
I know that bio-luminescence appears mainly where light is scarce, still, I wonder if I can create bio-luminescent "humans" without this environmental pressure.
In my mind, they would use bio-luminescence mainly for communication and more specifically for attraction. They would develop small spots of bio-luminescence in different places (head / hands / back ...). This bio-luminescence could be used at will and its colors could also be modified slightly (between 575 & 680 nm) according to the sensations expressed.
So my question is:
With a different evolution context from ours, could this characteristic be even scientifically plausible?
[Answer]
Yes, totally possible.
Many animals have traits and characteristics that have no practical use other than courtship displays. Think of the tails of peacocks, or the singing of frogs and crickets. In many cases, such displays cause those animals to be more vulnerable to predation, since a predator might find their prey more easily if they are being flashy or loud. Some people think that, by making such displays, those animals are showing to their potential mates that they are good enough in surviving that they can afford what would otherwise be, at best, a waste of energy.
I would even go as far as suggesting that this happens in humans. Having a musical ear does not make you stronger nor more fertile, but it helps you play the guitar, which sure is sexy.
Being capable of throwing a rave without the need of glow sticks could be another form of sexual display, and if so, the shinier people would be positively selected.
[Answer]
It would be plausible for communication only in absence of verbal language and (maybe) facial expressions. Since humans have language and no-verbal communication (posture, tone, volume of voice, facial expression), there is no need of another communication system. Facial expression in your case is not needed, because bio-luminescence develops in darkness.
It would be plausible for attraction. But this kind of solution for attraction usually happens only in enviroments with abundant resources (darkness isn't a place with abundant resources), where a species can waste effort for attraction. That is why birds in jungles are more colorful than birds in tundra.
[Answer]
Yes but you'll need a more passive predation scheme than what our ancestors had to deal with on Earth, certainly when it comes to nocturnal hunters. That's assuming that the "humans" in question always glow to some degree, if they can shut it down completely, or better yet it shuts down when not in active use then it shouldn't make much difference at all to the human condition not in terms of evolutionary pressure.
] |
[Question]
[
Here, star systems are connected with "wormholes". The wormholes facilitate travel at $250\ c$, regardless of mass. They are made using special ships. Any travel (including military vessels) not through the wormholes is well below light-speed (not more than $0.05\ c$, ).
It takes a road builder ship $50$ years to make each endpoint and $30$ years to make a light-year of "road". So, for example, to connect two systems $10$ light-years apart, a road builder ship takes $400$ years. A road cannot be constructed by more than 1 ship, not even by building from opposite ends. All of a road has to be built by one ship. Additionally, roads cannot intersect in the middle.
Here are some more information on the setting:
* FTL communication faster than the wormholes (at $10000\ c$) is available, but the transmission and reception equipment are too large for ships and are generally constructed on planets.
* The wormhole endpoints orbit the stars, and are indestructible and immovable for the purposes of this question.
* The possibility of simply making the trip without a wormhole remains.
* There are "countries" in this setup; a country contains around as many systems as there are cities in a real-world country.
* Two adjacent countries are generally connected (edge system(s) with edge system(s))
My question:
>
> How would governments connect their systems, and how would connection treaties be made (i.e. how the adjacent countries connect their countries)?
>
>
>
I picture only few (one?) connection between adjacent countries, because then only one system has to be defended in case of an invasion.
---
Edits in response to comments
* A wormhole endpoint is an endpoint of only 1 road.
* A wormhole endpoint is 100 km in diameter and cannot be "turned off" (for the purposes of this question).
* Even in the roads, light travels at lightspeed, so incoming vessels cannot be detected early.
[Answer]
# This is how railroads worked ~1914
Since your transit network has finite speed, the dynamics are very similar to how Europe worked in the age before cars provided competition to rail.
Powerful nation states sponsor railroad networks within them. The networks may be run by private interests (as in England), by the state (Germany and Russia) or a combination of the two (France wasn't [fully nationalized](https://en.wikipedia.org/wiki/SNCF#History) until 1938). But whoever runs them, the government controls how passes the borders.
Rail borders are obviously easier to control than the rest of the border, since railroads are discrete, but a border is continuous. Customs stations would be established at all crossings to ensure that appropriate tarrifs are paid, undesireables are kept out, etc.
Furthermore, in the case of Europe, not all railroads were compatible. In 1914, 1/3 of French railroads were narrow gauge as opposed to the standard gauge. Russia on the other hand, used 1525 mm broad gauge as opposed to the standard 1435 mm used for the main lines in the rest of Europe. This means that a train could not go direct from St. Petersburg to Paris; it would have to go to Warsaw, where the passengers would transfer to another train on a different rail system that would transfer. The Russians did this partially to ensure that rails could not be used by the rail stock of an invading German or Austrian army.
# To answer your question...
A nation would have multiple connections to other powers, in all the directions needed for fast communication with diplomatic and trading (and tourism, and immigration) partners. These connections would be pairs of wormhole endpoints. You come out of one wormhole, go through customs, then enter the other nation's wormhole.
The wormholes may have sufficient technical differences that prevent easy passage. For example, narrow gauge rail could be equivalent to wormholes that don't pass very large ships; big international merchant carriers would have to offload to smaller local merchantmen. The gauge change *a la* Russia might be a more technical aspect of the wormhole. Perhaps to transit a wormhole you need a specialized field generator, one certain nation's wormholes are only tuned to certain wormholes. This is the best way for a nation scared of invasion.
For nations prouder of their own army (like Germany was), and with no fear of invasion, defense of the borders depends on the threat of retaliation from the Fleet. Surely there would be a police force, but if you have a strong enough battle fleet, it isn't really justified to man an expensive fort if everyone else to too afraid to attack you. Also note that if diplomats and spies are common (as they were in Europe in 1914) it would be pretty much impossible to mount a surprise attack, given the logistics required.
[Answer]
The paranoid country has alliances with the neighboring countries and only wormholes to those countries (those being the only ones were STL threats are feasible) using their neighboring countries as buffers connecting to any other country they need access to. Further paranoia says that with each alliance at each wormhole both countries have significant military forces at the ready at either end of each connection.
] |
[Question]
[
I have this sci-fi story concept where patients in a comatose state can have their brains stimulated with VR. For instance, the VR can be a dream "game" that helps the patient process trauma. I can see that this idea is morally questionable and invasive, but I was just wondering about the plausibility of the technology itself.
The only real-world knowledge I currently have is that some patients who came out of their comas said that they had the capacity to dream, while a few of them recounted endless nightmares. Hence, I would assume their brains could somehow be stimulated to dream, despite injury.
Would such a technology be plausible in a sci-fi setting?
EDIT: Thanks for the input, guys! Another point - to explain the complexity of the technology, I think an AI controlling the dream-game would make sense, as it would be able to process the great number of possibilities the patient wishes to take on their "journey", and it can "learn" the patient's brain such that the neural fibers will be easy to navigate. I hope that makes some sense.
[Answer]
# Depends on tech level
Under our current understanding and technology this is impossible. Things we do not exactly know are:
* How do dreams work?
* Why are some people able to enter lucid dreams and others not?
* How do we stimulate nerves that precisely without turning the brain into mush by inserting too large/too many electrodes?
The last one is kinda important, because current VR systems use our real senses. Comatose patients hardly hear anything, hardly register touch, and hear things, well, hear things or not. They usually don't have enough brain activity to respond to anything, VR included, but brain activity *can* be electrically stimulated.
Technology you introduce must include:
* Far greater understanding of brain functioning. To be on the safe side, describe it from a point of view of a regular guy who knows there was breakthrough, but is no neuroscientist. That way it'll be easier for your readers to swallow.
* Ultra-thin electrodes and a way to insert them without damaging brain cells, or wireless brain stimulation, both to provide VR and to force enough brain activity for the patient to respond to VR.
* High-power computers to translate between dream and VR in realtime and compensate for any drift between the dream world and VR world. In a dream you can't just tell your user "operation not allowed". Any interaction that the user can dream about (literally) has to be allowed, or the illusion will break. This would require a VR game engine with nearly true-AI power.
With that level of understanding of brain functions and stimulation that precise I guess you could just wake up most of your patients. [This is already almost reality](https://www.scientificamerican.com/article/brain-stimulation-partly-awakens-patient-after-15-years-in-vegetative-state/). But if you want to say that, for example, the remaining 20% that did not woke up were rewired to VR, yeah, I'd read that novel.
[Answer]
There is not enough consciousness in the brain to interact with VR. Even if it could, it could be exploited. Such as the question in 2030 about ending someone's life is a crime, but it was thought that the person could be having a bad dream. So the same type of situation, such as a nightmare could be replayed over and over again in the VR, which would not be good for the sanity of the comatose person.
] |
[Question]
[
I've heard several schools of thought. From a hard science standpoint, could there be gravity on the habitable surface of a Dyson Swarm plate?
I keep thinking no. But if the outer shell were to be spun, could you generate a kind of artificial gravity?
[Answer]
A typical Dyson Swarm would have flat plates pointed at the Sun to maximize the surface area for the collection of solar energy (which is the point of having a Dyson Swarm in the first place). If you want to collect thermal energy, the mirrors would be parabolic with the focus facing the Sun in order to maximize the amount of thermal energy being gathered.
In either case, these devices could be spun in order to stabilize them and ensure they maintain proper orientation, providing centrifugal "gravity" around the edges.
The issue is solar energy collectors should be lightweight in order to make production, manoeuvring and so on quick and easy, and they should be specialized to generate the maximum amount of solar energy, so building them with a habitat attached seems a bit of a kludge.
The amount of area inside a Dyson Swarm would be so vast that purpose built rotating habitats ranging from "[Island 3's](https://infogalactic.com/info/O%27Neill_cylinder)" to "[Bishop Cylinders](https://infogalactic.com/info/Bishop_Ring_(habitat))" could easily be orbiting inside the swarm with thousands or hundreds of thousands of kilometers spacing between objects.
[](https://i.stack.imgur.com/oBnfc.gif)
*Island 3*
[](https://i.stack.imgur.com/FnTLh.jpg)
*Bishop cylinder*
To put this in context, an Island 3 is 8km in diameter and 30 km long, with an interior area of roughly 500 square miles, while a Bishop Ring is 500km wide and has a radius of 1000km, has an interior area of 3 million square kilometres. Each type of structure can house hundreds of thousands to millions of people (much of the population density can be decided by how the internal society wants to structure itself, a Bishop ring has the surface area of a small continent and could house billions of people, if desired).
Since a Dyson swarm with a 1 AU diameter has an area of 2.8×10E17 km2, there is room for millions of habitats, along with billions of solar collectors and other devices, so people and their industrial machinery can be separated by a comfortable distance.
[Answer]
Since a Dyson swarm (Dyson's concept of a Dyson Sphere) is really a bunch of individual satellites, you can make them spinning cylinders if you wish.
The object of the swarm is to intercept all or most of the light from the central star. This would require many layers of satellites in different orbits. I could even picture satellites that use panels that collect the waste IR of the more inner orbits.
A solid dyson sphere or ringworld is highly unstable and will eventually intercept the star. This is because the star's gravity effects each side of the object the same, so there is no net gravity to hold it in place. This is why Larry Niven's sequel to Ringworld added rockets to keep it in a stable orbit.
I used a dyson swarm for a game once, and I used plenty of "magic" to make it an interesting setting for a game, such as hyperspatial tunnels between the satellites and robots who (unseen, underground) kept the ecology going.
[Answer]
If you use an orbiting formation of "pie plates" per the intermediate step in constructing a ringworld laid out in Larry Niven's *[Bigger Than Worlds](https://en.wikipedia.org/wiki/Bigger_Than_Worlds)* essay then yes you can have "gravity". In fact you have to have pseudo-gravity on such a structure due to linear acceleration towards the star to maintain a stable orbit. The amount of gravity you would experience in such a system depends on the orbital velocity and range of the plate involved as that will dictate the inward counter-acceleration needed to maintain a stable orbit.
] |
[Question]
[
Is there some astronomical / physics reason why it would (or would not) be realistic to have more than one "larger-than-Earth-moon" object in an alien sky as backdrop to a movie or tv show?
In other words, the view of Earth from our moon is quite impressive (takes up around 6 degrees of sky compared to how much the moon takes up in Earth's sky (0.5 degrees).
Often, to emphasize "you're now on an ALIEN planet," the sci fi writers will place multiple (usually 3) moons/planets in the sky. And they are usually shown larger than what the Moon would look like from Earth (so, larger than 0.5 degrees.)
Would this be realistic in the real world? In other words, in our solar system, Mars and Venus are so far away from us that they appear tiny, as stars.
However, if the Earth was a moon of Jupiter, then presumably, Jupiter would look huge in our sky, and if we *also* retained our moon, the Moon would look "moon-sized" in our sky, thereby having at least two large objects in our sky.
Or would an object the size/density of Earth not be able to both be a moon of a gas giant, while simultaneously having a large moon such as Luna?
[Answer]
## Big objects in night skies
Well, consider, for example, a moon of Jupiter. This moon would have Jupiter in the sky, along with whatever assorted moons were bopping along that night. This would fulfill your requirements for plausibility.
To quote Wikipedia's convenient article on [extraterrestrial skies](https://en.wikipedia.org/wiki/Extraterrestrial_skies#The_skies_of_Jupiter%27s_moons):
>
> For an observer on Io, the closest large moon to the planet, Jupiter's apparent diameter would be about 20° (38 times the visible diameter of the Moon, covering 1% of Io's sky). An observer on Metis, the innermost moon, would see Jupiter's apparent diameter increased to 68° (130 times the visible diameter of the Moon, covering 18% of Metis's sky).
>
>
>
Another example would be that of the skies of Enceladus, a moon of Saturn. To quote wikipedia again:
>
> Seen from Enceladus, Saturn would have a visible diameter of almost 30°, sixty times more than the Moon visible from Earth [...] An observer located on Enceladus could also observe Mimas (the biggest satellite located inside Enceladus's orbit) transit in front of Saturn every 72 hours, on average. Its apparent size would be at most 26 minutes of arc, about the same size as the Moon seen from Earth. Pallene and Methone would appear nearly star-like (maximum 30 seconds of arc). Tethys, visible from Enceladus's anti-Saturnian side, would reach a maximum apparent size of about 64 minutes of arc, about twice that of the Moon as seen from the Earth.
>
>
>
Now, let's compare sizing of these moons and the Earth. Io has a radius equivalent to .286 Earth radii, and Enceladus a radius equivalent to 0.0395 Earth radii. So much smaller than Earth.
## Earth size
This may seem mildly discouraging, but in fact, it is quite possible for an Earth sized object to orbit Jupiter. According to [this reddit thread](https://www.reddit.com/r/askscience/comments/23a96x/could_an_earth_sized_object_orbit_jupiter/):
>
> There's no reason I can think of why Jupiter couldn't have an Earth-sized moon.
>
>
> In principle, I don't see a reason why a Jupiter-sized planet couldn't have an Earth-sized moon. The only limitation I can think of that would prevent an Earth-sized moon to orbit around Jupiter is the Roche Limit. The Roche Limit describes the distance at which an object would be ripped apart from the gravitational tidal forces exerted on it by the larger object. It's essentially the same principle as how our moon exerts tides on the ocean, but on a much larger scale.
>
>
> If we assume that the Earth is a sphere with constant density (it isn't, but let's do this for easy calculations), we can use the equation you can find on the Wikipedia page to calculate the limit. Plugging in for the mass of jupiter (1.9x1027 kg), the mass of the Earth (6.0x1024 kg), and the radius of Earth (6378 km), we get that the Roche limit for the Jupiter/Earth system is about 5500 55000 km away from Jupiter's center of mass.
>
>
> Since Jupiter's radius (69900 km) is much larger than the Roche limit, then there should be no problem with an Earth-sized satellite orbiting Jupiter at any arbitrary distance, as long as it wasn't actually touching Jupiter.
>
>
>
## tl;dr: yes, it's quite reasonable for big objects to be in an earth-sized planet's alien sky.
] |
[Question]
[
If there was a supermassive structure built on earth (30km tall, 10km wide/deep tower with slightly slanted faces), what sort of effects would this cause on the surrounding areas? Specifically, what effect would this have on clouds, wind, and precipitation? What are the effects of a shadow this size on surrounding ecosystems? Could it be possible to create an entirely new “vertical” biome on the faces of this structure?
[Answer]
Let's put this in perspective here:
30km is 30,000 meters.
There are 14 mountains in the Himalayas that are over 8,000 meters. Your building is insanely high. If you are talking about having some kind of vertical biome it would have to be enclosed. Just think of what kind of life lives at the peaks of the highest Himalayan mountains. Exactly. And that's not even up to one third of the height of your megastructure. So I would say having a vertical biome on the faces of the structure might only be possible at lower elevations in the bottom fourth of the building. Then you would have to have a way to change the atmospheric pressure inside and oxygen levels inside the building also. But that's not your question.
---
Environmental/Meteorological effects. There would be a massive shadow, for sure. Also depends which hemisphere your building is in. Let's assume it's the north. Then the northern side of the building will have shorter vegetation, moss, lichen, due to less sunlight. It'll be colder, snow will stay on the ground longer. 10,000 meters of shadow is pretty significant.
There sheer size of the building could break up cloud formations.. may form heavy condensation (?) on the sides of the building. Of course one side could be protected from prevalent winds come from a specific direction, but that would be more apparent the closer the location to the building.
[Answer]
It will be windy around the tower.
Might be more precipitation as clouds will be forced up along the walls.
You might get hail, or maybe even avalanches from ice that forms high up on the tower.
The massive shadow will stunt plant growth, but only at a short distance since motion of sun will still provide almost the same amount of sunlight to places only a few km from the tower.
Vertical biome assumes there are cracks and holes for plants and animals to live in. But that means that the tower material is weathering, so it will collapse pretty soon (maybe couple hundred years). If somebody is maintaining the tower, they will keep all life off it. If you really want biome on it, have it made from indestructible material, but with nooks and crannies to accommodate living things.
Edit: you have to think about how this thing was built. If it was built from local materials, there will probably be a good sized lake (or a few missing mountains) nearby. The weight of it might push the entire area down. And you will need some super-strong materials, or hydrogen balloons to deal with weight.
[Answer]
you may have something like a Chinook effect similar to Alberta depending on the geography. For those who don't know a Chinook is when moist air from off the coast gets pushed uphill losing temperature and thus its water carrying potential raining/snowing on the coastal side of the vertical climb and when descending the far side of the slope the air is much warmer and drier. This isn't the most scientific explanation and will update this later.
] |
[Question]
[
A book that I'm currently writing called Surge features an enemy faction called the Degenerates that are heavily inspired by the Scythians (Indo-Iranian horse nomads that ruled the Eurasian Steppe and Central Asia from the 9th century BC to the 1st century CE) and consists mostly of humans parasitized by a prehistoric worm-like endoparasite called Echidna, which parasitizes and radically alters the entire physiology of a wide variety of organisms from the phylum Chordata.
Parasitized humans are transformed into nocturnal humanoids that are facultative quadrupedals and divided into three distinct subspecies, named after the sons of Hercules and Echidna (all of which were ancestors of the Scythians):
* Agathyrsus (Physically imposing and immensely strong Degenerates used mostly as shock troops, cataphracts and heavy infantry)
* Gelonus (Lightly-built and multi-armed Degenerates which act as scouts, light infantry and cavalry whose purpose is to advance beyond their own front lines for the intent of harassing enemies from afar)
* Scythes (Degenerates that have excellent vision and are deployed as marksmen and mounted riflemen, who engage their targets at long range).
Human-spawned Degenerates can only reproduce by giving live birth to thousands of Echidnae that are used to convert more humans into potential Degenerates, due to the Echidnae hijacking their reproductive system. Because of this, Degenerates are constantly capturing humans to use as hosts and have compact skulls with specialized jaws that can grasp and carry envenomated humans by the neck, allowing them to be brought underground for conversion. I have no idea what sort of jaws such a creature would have, especially ones that have teeth for consuming plants and meat along with a set of myotoxic fangs used to paralyse humans.
[Answer]
You want a creature with a human skeleton which can carry an adult human in its mouth. The problem with doing it like a cat is that humans have no scruff. I proposed this method here
[How to make a saddle for a feline mount](https://worldbuilding.stackexchange.com/questions/95427/how-to-make-a-saddle-for-a-feline-mount/95434#95434)
but the dwarves being carried wear special scruff-shirts.
For your creature, starting with the base human plan, the modifications you need are great but not impossible I don't think; the fang is the hardest. It would be more difficult to achieve starting with an adult; you might want to assert that the Degenerates who are so modified are exclusively those who are initially captured and transformed as babies. Adults go on to become other types.
A gorilla jaw is close to ours and would work to carry humans. They have big flat herbivore teeth and two tusklike canines at the front which would help keep a human body from rolling forward.
[](https://i.stack.imgur.com/8JICA.jpg)
<https://www.researchgate.net/publication/260040771_Ontogenetic_Variation_in_the_Mandibular_Ramus_of_Great_Apes_and_Humans>
A gorilla jaw is not long enough to fit a human body on the chewing teeth behind the incisors. I measure this jaw to be 6 cm; I think you would need 36-40 cm of tooth expanse to let the body rest atop the teeth.
You could accomplish this by giving your creature a very horizontally elongated skull like that of a horse.
[](https://i.stack.imgur.com/wSPr0.jpg)
[https://www.amazon.com/3B-Scientific-T30017-Horse-Caballus/dp/B005DTI8PW](https://rads.stackoverflow.com/amzn/click/B005DTI8PW)
Or you could just greatly exaggerate the jaw and have it protrude out, with our without teeth. Those protruding teeth would have no corresponding upper teeth. An expanse of toothless gingiva with the tusks in front would be fine for carrying a body. An exaggerated mandible is called [mandibular prognathism](https://en.wikipedia.org/wiki/Prognathism).
[](https://i.stack.imgur.com/KV5NJ.png)
Persons with pituitary gigantism (like Andre the Giant) have problems with this since for whatever reason the mandible can keep growing after the rest of the adult has reached maximal skeletal growth.
---
You also need to adjust the stance or your creature will be way overbalanced forward. The gorilla again - gorilla stance would be a much better way to carry a weight on the jaw.
[](https://i.stack.imgur.com/RyQIY.jpg)
<https://gorillafund.org/giranezas-group-involved-in-another-interaction/>
You would need to greatly augment the neck and jaw muscles which would get your head looking like a gorilla also.
---
So: your humanoid which carries other humans in its jaws would look like a large gorilla, go as a quadruped when carrying, and have a very elongated jaw or muzzle with huge anterior canines, so the carried body could simply rest on the jaw with no bite force being necessary to retain it.
This thing would be formidable too - when not carrying people the combination of strong neck and jaw muscles and those giant anterior teeth would let it fight like a boar. I suspect the flat teeth would mean it is a herbivore - no shame there.
Re the fangs - they will get in the way and risk being broken off. Consider that these could be extensible like cat claws, to keep them out of the way when fighting / eating. The venom fang might be better not on the jaw - male platypi have poison spines on their legs.
] |
[Question]
[
I watched [this](https://m.youtube.com/watch?v=My4RA5I0FKs) video. A network of pipes blows air at the bottom of a bathtub filled with sand. The sand behaves just like water. Objects can float or sink in it. Children can play in it.
So, my creature is worm-like. It has a snorkel which it holds above the sand to suck air. The creature has many vents which blow the air in the sand, both around and in front. The sand around the creature becomes fluid-like (quicksand) and the creature can swim in it.
Is that a feasible way to swim in sand? Can larger creatures like the worm from Dune series swim this way? I still think the creatures must find a way to keep their snorkel above the sand at all times, or else they risk inhaling sand into their lungs.
[Answer]
So no, the air pipe idea is probably not feasible for swimming through sand.
But a worm shape probably is.
MIT scientists have been studying vertebrates to find out how they move through sand. Basically, the smoother your creature's outer surface, to reduce drag from friction against the sand, and the more vertebra it has, to enable curving motions, the more likely it is to be able to "swim" through sand.
To scale it up from worms, snakes, and lizards to something like Shai-Hulud, I'd consider how the interior organs would adapt. If it moves from deep within the sand to the surface regularly, then it's going to experience increasing and decreasing pressure changes from the weight of the sand on top of it. How will it do that without getting its version of the bends?
The MIT Review blurb is here:
<https://www.technologyreview.com/s/416229/how-to-swim-through-sand/>
Wired Magazine's story on the study is here:
<https://www.wired.com/2011/02/sand-swimming-robot/>
...and since Wired's video is down, you can watch New Scientist summarizing the lizard study here:
<https://www.youtube.com/watch?v=9mwJsGbTkOk>
...and the NYT summarizing the snake study here:
<https://www.youtube.com/watch?v=Lqw2YrPNB9U>
[Answer]
No, it really isn't possible (without magic) to have a worm-like creature move through substrata at the rate they portray, even if you were somehow able to figure out how to apply enough air with enough consistency to give sand a liquid effect, because at that point, it'd basically be swimming/flying. That being said, worms travel through the dirt below our feet every day, as do a myriad of other invertebrates and vertebrates, so the process isn't entirely alien.
] |
[Question]
[
I'm Wyvera, a young female writer. I've been working on a science fiction project for more than a year now. This project, which I will eventually turn into a novel series, is supposed to remain as scientifically-plausible as I can get it to be. I've mostly succeeded, but there's one science field that I... kinda suck at. That's chemistry.
I've been adding fictional elements to this project because it features alien worlds, and I started adding fictional elements not too long ago as to give it more variety, creativity, and allow more aspects to be added to it in general. I've also been considering alternative biochemistry, but I kinda stink at that too. For nearly a month I've been looking around the internet, trying to find somebody who was at least experienced in chemistry, to no avail. I found this place recently though, so hopefully, I can get something.
So I'll list down some questions I have for it. Ask if I need to specify more:
1: Is alternative biochemistry possible? If so, what elements could work for it? Silicon? Ammonia? Boron? Methane?
And how would life be different depending on the elements used?
2: Could an element let almost all lifeforms, even those that breathe in different things, breathe it in and work safely in an atmosphere?
Could it also be produced by alien flora somehow?
3: Is Sodium (or salt) able to be an alternative energy source for alien plants that reside on a very dry planet? Could flora even grow on bare rock with no soil?
People have probably asked something like this before, but I kind of don't have the time to look through questions at the moment, and I wanted to get this answered soon. Thanks for taking the time to read this! Excuse any newbie-esque behaviors here or any cluelessness with science, I'm still pretty new.
[Answer]
I'll let others focus on plausible alternative bio-chemistry configurations, but I wanted to do my best to explain to you why *our* biochemistry works so well. The first thing you need to know is that bio-chemistry is all about energy release.
Let's start with the basic food that all living things need; carbohydrates. These are Carbon, Hydrogen and Oxygen. What do these three elements do? Well (and this is a bit of a simplification but functionally correct) the hydrogen provides energy, which the oxygen releases, and carbon allows our cells to combine molecules in many different configurations to either store or release energy.
Carbon based life forms are possible because Carbon is a relatively simple element that can connect to multiple different elements *simultaneously* to form complex molecules. Water is essential for life because it's an extremely stable molecule (H2O) which stores the two primary elements needed to generate energy. Water is (quite literally) rocket fuel stored in its lowest energy state.
Now we get into endothermic v. exothermic reactions. All these words really mean is that chemical reactions can either consume energy (endothermic) or release energy (exothermic). Photosynthesis is an endothermic reaction. It takes CO2 and H2O, both low energy state molecules, applies sunlight to transform them into O2 and Carbohydrates, which are higher energy state molecules.
Plants (and animals) get their energy by consuming the carbohydrates, mixing them with O2 so that they revert to their lower energy states (CO2 & H2O), keeping the released energy for themselves.
The important thing to note here is that ALL these chemical elements are relatively simple, and relatively common in the universe as a result. From a physics perspective, you have to remember that our current theories tell us that the only element that existed in the early universe was Hydrogen, which gets converted via fusion in the heart of stars into heavier elements. The heavier the element, the bigger the star required and therefore the more rare its going to be (again, a simplification but functionally accurate).
So, while things like silicon have been suggested as alternative bases for life, they're less likely because it's a heavier element than carbon. Again, this area I'll leave for people better qualified than I to explain.
Regarding your questions about flora, the answer is probably no. Plants on earth exist because they can use photosynthesis to generate the critical molecules for their own use, but they still need water to do that. Additionally, plants need soil (not just for water but) for the complex minerals that they extract from it. They also rely on many different microscopic bacterial functions occurring in the soil, without which they cannot grow themselves. Soil (as opposed to rock) can absorb water, see minerals shifted around inside through bacterial functions, and provide a medium in which roots can grow without having to split the rock to do so. Sodium Chloride (NaCl, also known as salt) isn't an alternative energy source to water; it's hydroscopic (meaning that it reacts with water and stores it) which is why salt can be useful to life.
With regards to plants making other chemical molecules required to breathe in non-carbon based life forms; this is possible but would still require an endothermic reaction. The reaction (like in plants) would have to produce an excess of the life giving molecules, which get released as a 'waste' gas.
Mind you, if that was the case, it's possible that some form of mobile life form (for now let's call it an animal) may also be capable of photosynthesis in some form, or geo-synthesis (using geothermal heat to generate the same effect) or some other form of energy capture.
Ultimately, I suspect that if we do find extra-terrestrial life out there it's likely to be carbon based purely because of the availability of the elements required (probability) and the simpler chemical reactions required to get it going (efficiency). Either way, don't get hung up on Earth based life and the distinctions we have between plants and animals. Any life form capable of storing energy in chemical form through an endothermic reaction could lead to a diverse ecosystem on its home planet.
[Answer]
**1: Is alternative biochemistry possible? If so, what elements could work for it? Silicon? Ammonia? Boron? Methane? And how would life be different depending on the elements used?**
This one is too broad. There is a lot written about it.
**2: Could an element let almost all lifeforms, even those that breathe in different things, breathe it in and work safely in an atmosphere? Could it also be produced by alien flora somehow?**
Your atmosphere would need to be comprised of a gas that was very stable, very nonreactive and minimally soluble. Our atmosphere of nitrogen gas (N2) meets some of those requirements. Organisms that metabolize via [denitrification](https://en.wikipedia.org/wiki/Denitrification) generate N2 gas. An atmosphere of a noble gas (argon, krypton) could meet those requirements too though I cannot think of how organisms would generate it.
Perfluorocarbons would make a very inert, stable and interesting atmosphere.
[](https://i.stack.imgur.com/I7Y3s.jpg)
<https://www.reddit.com/r/WTF/comments/x4i61/fact_this_mouse_is_alive_and_breathing_liquid/>
The problem with a shared atmosphere is the requirements we have of atmosphere. Suppose I want to share atmosphere with an ammonia breather. I want O2 in my atmosphere which will burn the ammonia breather. The ammonia breather wants ammonia which will make me cough and choke. Even if it is just a trace of each in inert N2, we cannot share atmospheres.
3a: **Is Sodium (or salt) able to be an alternative energy source for alien plants that reside on a very dry planet?** I think so and it is a cool idea. [Hydration of a dry salt kicks out a lot of energy](https://en.wikipedia.org/wiki/Hydration_energy). If you hold a pile of sodium chloride in your hand and wet it gently you might feel the heat. With a different salt like calcium chloride or sodium borate you will definitely feel heat. An organism which could take up dry salt and hydrate it in a controlled manner could definitely use that for energy. The problem: you need water. But it is possible to make water metabolically.
3b: **Could flora even grow on rock with no soil?**
How about this lichen?
[](https://i.stack.imgur.com/weJnr.jpg)
<https://easternplant.blog/category/rock-tripe/>
[Answer]
1. Alternative biochemistry is feasible (but nobody really knows if it's possible). Our life is carbon-based. Other bases like silicon, nitrogen, boron etc. are theoretically possible, but look increasingly unlikely. You don't have to switch the base, though. You can start with the same carbon base, but have a different set of elements (on Earth, its mostly Nitrogen, Oxygen and Sulfur) to enhance the base.
2. Our preferred oxidizer is Oxygen. Other oxidizers like Chlorine or Fluorine are possible, but for most Earth lifeforms they are deadly toxic in high concentrations. On a different planet, atmosphere can be a mix of several reactive gases, and organisms should be ready to tolerate that. However, it would be unlikely for two separate kingdoms of species to breath in two different gases.
3. Metallic sodium would be a good source of chemical energy, but it is very reactive and is not occurring naturally. An organism may, in theory, produce it and store internally. Sodium chloride (commonly known as the salt) is a very important source of elements, but its energy value is virtually zero.
Primitive flora like lichen can grow on bare rocks. More complex plants rely on soil to provide important nutrients. There is [hydroponics](https://en.wikipedia.org/wiki/Hydroponics), which does not require soil, but that means that the nutrients should be supplied artificially.
[Answer]
So for this I'll do my best to answer your first two questions(don't know much about the other two) and hopefully it helps, so for different elemental bases your going to want an element with 4 valence electrons which just so happen to be Carbon, Silicon, Germanium, Tin, Lead, Unanquadium, Hoimium, and Einsteinium. Now unless your life has away of controlling or using nuclear decay the last three may not be for you and Germanium is two uncommon to likely be a base for life so your left with those 4. Also one important thing to consider when making aliens out if these different elements is what is the waste product, by that I mean when you mix carbon and oxygen you get carbon dioxide, but when you do the same with silicon and oxygen you get silicon dioxide, and silicon dioxide is sand, so either this life form lives at a higher temperature than earth or has a sand coming out his nose. Now if you want to keep the carbon and still have the life be exotic then you can go with methane based life which would need a chilly place to live to meet the three way point of methane, somewhere like Titan. But methane based life isn't just methane it's methane and Ethane mixed together and it would require an atmosphere of methane, nitrogen and hydrogen without any of that pesky oxygen getting in the way. Boron based life would require a very thin atmosphere and couldn't handle ours without blowing up faster than contraversial PewDiePie video, yeah It's very reactive. And no, no know element could let a bunch of these aliens share a workspace together, but you could handwave some invisible atmosphere suits
Here are some links that go into alien biochemistry into more detail
<https://en.m.wikipedia.org/wiki/Hypothetical_types_of_biochemistry>
<https://listverse.com/2015/07/17/10-hypothetical-forms-of-life/>
<https://www.google.com/amp/s/www.popsci.com/amp/bacteria-have-bonded-carbon-and-silicon-for-first-time-what-can-they-teach-us>
] |
[Question]
[
There's an absolutely gargantuan mountainside, with a peculiar climate. It has roughly a kilometer between where the woods stop and the snow falls, where an equally large priory ekes out a living. The various monks never leave the mountain, and live entirely on what they grow. What plants could exist here that can feed a large congregation of people, thrive on the rocky, barren soil, *and* persist with minimal rainfall?
[Answer]
As well as terracing and growing imported crops in protected environments within and around their monastery there would have been a lot to find in the high alpine valleys further afield. Provided there we’re not too many of them and they had scope to roam over a large enough area they should have been able to find enough food. Some are listed below from this reference <http://edoc.unibas.ch/34764/>
There are plenty of forgotten wild edible plants and in the past a lot more were probably used. Swiss alpine cantons, especially the canton of Valais, still have a viable tradition. And 98 edible plant species, which belong to 38 families, have been identified.
Plants were classified in eight categories based on the way they were traditionally used including salads, cooked vegetables, spices, alcoholic drinks, teas, syrups, jams, and raw snacks. The categories with the highest number of citations were teas (18%), followed by cooked vegetables (16%), jams (16%), and raw snacks (16%).
Taraxacum officinale, Sambucus nigra, Chenopodium bonus-henricus, and Urtica dioica were the most cited plants and most commonly used in the different valleys. Knowledge on edible plants is found from its origins in agriculture and activities as shepherds. Books written in the XIXth and early XXth centuries have documented these uses and have allowed identification of around 40 food plants, which had already fallen in oblivion (e.g. Bunium bulbocastanum).
Two traditional edible plants (Phyteuma orbiculare and Cirsium spinosissimum) were submitted to a thorough phytochemical investigation.
The first species investigated was the round-headed rampion (Phyteuma orbiculare L., Campanulaceae). The sweet flowers of the plant were consumed by shepherds as raw snacks, whereas nutty-tasting leaves (rosettes) were eaten as a salad. 23 substances including different polyphenols, fatty acids, and triterpenes were identified from dried aerial parts.
Phyteuma orbiculare contained interesting amounts of ascorbic acid, beta-carotene, polyphenols, polyinsaturated fatty acids, calcium, magnesium and potassium
This food plant, which possesses interesting nutritive properties and favorable breeding predispositions, could be an interesting candidate for further agronomic development.
The second plant to be investigated was a thistle, Cirsium spinosissimum (Asteraceae). Surrounding leaves and the pappus hairs were removed before consumption, and the receptacle was eaten in early summer time. Taste of the receptacle is similar to that of an artichoke, and its consistency is tender. A total of 20 substances including polyphenols, a monoterpene lactone, fatty acids and a spermine derivative were identified.
This plant contains vitamins and polyunsaturated fatty acids in low amounts, and an interesting level of potassium. Cirsium spinosissimum is not really convenient for further cultivation due to its spiny morphology.
Other alpine edible plants selected during this work could be interesting with regard to their chemical composition, and for future breeding. They should be the main focus of further investigations. The establishment of alpine plants as new food crops would represent a diversification of the activities in mountain agriculture.
[Answer]
If the monks have been there for several generations, they have probably carved out terraces where soil can be collected and irrigated for farming.
If a warm humid wind usually breaks against the foot of the mountain. much of the wet air would push up along the face of the mountain, settling into the wind breaks caused by the terraces and shedding their moisture along the way. Wet wind which passes over the terraces would cool against the heights above, returning their water as condensation, dripping down the cliff face.
This wouldn't be the kind of farm where food just grows. It would be a work of man; productive only because monks regularly augment its natural resources with freshly composted earth and melted snow water.
If the monks work hard enough to keep the soil fertile, they could pretty much grow anything which can handle their mountainside micro-climate.
[Answer]
>
> It has roughly a kilometer between where the woods stop and the snow falls
>
>
>
The fact that no trees grows in that area suggests that it can be an environment where [lichens](https://en.wikipedia.org/wiki/Lichen#Food) can grow. And of course they can be used as food, both for man and for animals.
>
> Lichens are eaten by many different cultures across the world. Although some lichens are only eaten in times of famine, others are a staple food or even a delicacy. Two obstacles are often encountered when eating lichens: lichen polysaccharides are generally indigestible to humans, and lichens usually contain mildly toxic secondary compounds that should be removed before eating. Very few lichens are poisonous, but those high in vulpinic acid or usnic acid are toxic.[110] Most poisonous lichens are yellow.
>
>
> In the past Iceland moss (Cetraria islandica) was an important human food in northern Europe, and was cooked as a bread, porridge, pudding, soup, or salad. Wila (Bryoria fremontii) was an important food in parts of North America, where it was usually pitcooked. Northern peoples in North America and Siberia traditionally eat the partially digested reindeer lichen (Cladina spp.) after they remove it from the rumen of caribou or reindeer that have been killed. Rock tripe (Umbilicaria spp. and Lasalia spp.) is a lichen that has frequently been used as an emergency food in North America, and one species, Umbilicaria esculenta, is used in a variety of traditional Korean and Japanese foods.
>
>
>
] |
[Question]
[
I have a homebrew setting with a moon that has some specific features orbiting an Earth sized planet, and I'm trying to find out how these features would affect how the moon looks from the surface of said planet during the night.
It's a binary star system, with two sun-like stars roughly 1.5 AU apart surrounded by a [cloud of argon gas](https://worldbuilding.stackexchange.com/questions/64692/what-could-make-a-star-violet). The planet has the same mass and atmospheric composition as Earth, and is roughly 4 AU away from the stars. The moon is essentially the same as Luna in every way, except that it has a large obsidian core with a thick layer of colorless and transparent [petalite](https://en.wikipedia.org/wiki/Petalite).
TL;DR: What does this moon look like at night?
Thank you for any help provided!
[Answer]
I think the space argon would blow away in the solar wind.
I think the obsidian core would not affect how the moon looks, because it is on the inside. Maybe if there were a crater deep enough to unearth some of the obsidian it would be darker than adjacent moon, because obsidian is dark.
The surface of Luna is made of plagioclase feldspar.
<https://en.wikipedia.org/wiki/Geology_of_the_Moon>
>
> Lunar rocks are in large part made of the same common rock forming
> minerals as found on Earth, such as olivine, pyroxene, and plagioclase
> feldspar (anorthosite). Plagioclase feldspar is mostly found in the
> lunar crust, whereas pyroxene and olivine are typically seen in the
> lunar mantle.[15]
>
>
>
[Feldspar](https://en.wikipedia.org/wiki/Feldspar) is an aluminum containing mineral. Petalite is very similar and differs in that it contains lithium instead of potassium; I found petalite described as "lithium feldspar". The moon's surface is broken up into dust and tiny bits from impacts. When broken into tiny bits I do not think one can distinguish potassium feldspar from lithium feldspar by sight. Take a look.
[](https://i.stack.imgur.com/NhM81.jpg)
[](https://i.stack.imgur.com/wPPg0.jpg)
As regards albedo and color I think the proposed petalite moon would look like Luna does now.
With one exception: this moon has 2 suns and so it would be lit from 2 angles, and so there would be 2 different crescents as the moon went through its phases: one crescent brightly lit by both stars, one dimmer crescent lit by just one star and the remainder dark and unlit. If anyone feels motivated to Photoshop 2 phases of the moon on top of each other, please feel free to add your image in an edit. MS Paint is not up to that job, it turns out.
] |
[Question]
[
I am wondering about [Tatooine](https://en.wikipedia.org/wiki/Tatooine), and was reading about binary systems [here](https://worldbuilding.stackexchange.com/questions/86495/is-a-11-earth-possible-in-a-binary-system), which provided a lot of good basic food for thought. My specific question is not addressed at that link, and so I pose it here.
Would the two suns (*a la* Tatooine's, not the other possible binary configurations at the link) likely both lie in an ecliptic? I believe they should, but am not certain. if they do (please confirm):
* I believe at some timepoints, one sun is visible in the sky (a sun-on-sun eclipse).
* At other times, they could be discerned as two bodies, and the distance between (and rate of change) would depend on how quickly they are orbiting one another.
* Intriguingly, there might be two sunsets (again, similar to Luke's view) - and I think if so it would have to do with how far apart they are. I think the rotation of the planet allows two sunsets for two suns lying in an ecliptic with a planet. Is my space perception way off, here?
There could be double-shadow effects too, which could be used for navigation or other maths, I suppose.
[Answer]
## Most likely, yes.
I wrote an answer [here](https://worldbuilding.stackexchange.com/a/72508/627) discussion how binary stars are born. The relevant part here is that there are [several main theories](http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1988ComAp..12..169B&defaultprint=YES&filetype=.pdf) for [how binary stars form](https://www.astro.princeton.edu/%7Eeco/AST541/Mary_Anne_Peters.pdf):
1. **Capture:** In an interaction between three stars, two become bound together while the third one is ejected away. This is unlikely to be the major formation mechanism for most binary systems.
2. **Separate nuclei:** Two stars formed very close to one another, close enough to start orbiting each other. This is also very unlikely to happen.
3. **Fission:** A protostar collapsing from a gas cloud to a normal star splits in two after some instability forms. Modeling so far rules this mechanism out.
4. **Fragmentation:** Fragmentation is to some extent like fission, except it involves the gas cloud itself splitting before a protostar forms. This is generally viewed as the accepted way most binary star systems form.
Depending on which hypothesis is true, circumbinary protoplanetary disks should form in the same plane as the orbits of the stars, meaning that the ecliptic *would* match up (see [these notes](http://astro.cornell.edu/%7Edong/talks/aspen-planet.pdf) for more details). There might be some variation - maybe less than 10 degrees - but not much.
In the case of planets orbiting only *one* of the stars, things are different. There are plenty of cases of single-star disk misalignment in young binary systems. For instance, [**Jensen & Akeson (2014)**](http://www.nature.com/nature/journal/v511/n7511/full/nature13521.html) looked at the young system HK Tauri and measured a misalignment of 60 to 68 degrees between the protoplanetary disks around each star, meaning that at least one is rotated quite far outside the orbital plane of the stars.
Let me address your specific points.
>
> I believe at some timepoints, one sun is visible in the sky (a sun-on-sun eclipse).
>
>
>
This will be possible, yes, but bear in mind that one star may not fully cover the other, so you'd almost certainly be able to see parts of both.
>
> At other times, they could be discerned as two bodies, and the distance between (and rate of change) would depend on how quickly they are orbiting one another.
>
>
>
This is correct.
>
> Intriguingly, there might be two sunsets (again, similar to Luke's view) - and I think if so it would have to do with how far apart they are. I think the rotation of the planet allows two sunsets for two suns lying in an ecliptic with a planet. Is my space perception way off, here?
>
>
>
Yes, this is also possible. For a planet orbiting both stars, assuming Earth-like rotation, there will always be instants where each star sets separately, as viewed from a certain point on the planet.
[Answer]
Yes.
Star systems form when a cloud of interstellar gas and dust collapses under its own weight. See [Jeans instability](https://en.wikipedia.org/wiki/Jeans_instability). When this happens, the cloud is almost certainly going to be rotating just a bit. This means that the cloud has some angular momentum. As the cloud collapses, it starts spinning faster and faster so as to conserve its angular momentum, causing the cloud to flatten into a disk. And a disk it will remain, even as the gas and dust coalesces into planets and a star, and the stellar wind from the newly-formed star blows the rest of the gas and dust away.
Some binary systems\* form in exactly the same way, except by producing two star-sized clumps of matter instead of just one. If these form close together at the center of the protostellar disk, the result is a Tatooine-like system that could well have planets orbiting the stars' combined center of mass. If they form very far apart (a few dozen AU, perhaps), then the result could be the other type of binary system, with planets orbiting each star individually.
In either case, the stars and the planets will all lie in the same plane (that is, the ecliptic plane), at least at first, since that's where all the matter that formed them was. However, that's not to say both stars and all the planets will always lie in the ecliptic. A close call with another star or another star system can disrupt the orbits of the planets or even the stars themselves. Do note, however, that such encounters will almost certainly affect the planets in a Tatooine-like system before they affect the stars. So a Tatooine-like system with multiple planets where the only things orbiting on another plane are the stars is highly unlikely.
\* Binary systems can also form when a single-star system captures another star from somewhere else, but you won't get a Tatooine-like system this way without destroying both stars' planetary systems completely.
] |
[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 is perfectly fine, but for generations, not a single human has seen sunlight. Earth is completely covered in black fog, reaching high up into the atmosphere, so that not even skyscrapers can escape it.
The fog is actually made of microscopic organisms. In the upper layers of the atmosphere, they photosynthesize. Dead microbes eventually drift down to the ground, creating a rich black soil that feeds fungus and other lifeforms.
Across the whole world, the fog utterly blacks out the sky, and even at ground level, it is dense enough to limit visibility to under a hundred feet, even with a powerful torch (of course, since there is no sunlight, a human would need some artificial light source to see at all). This level of fog is roughly similar to a perpetual [Tule fog](https://en.wikipedia.org/wiki/Tule_fog).
The problem: thick atmospheres lead to greenhouse conditions on a planet, but Earth must remain habitable for human-like creatures.
How can I keep our world from turning into a Venusian hellhole?
The fog is genetically engineered by a sufficiently advanced intelligence, so any hard science answer is acceptable.
[Answer]
/thick atmospheres lead to greenhouse conditions on a planet/
Venus has a huge greenhouse effect because their atmosphere contains a metric buttload\*of CO2. This makes the Venusian atmosphere "thicker" as well because CO2 is more massive than N2 or O2.
If you add a heavier gas like CO2 to the atmosphere it will increase atmospheric pressure, because the gas column above you will be more massive. If a given volume of floating fog microbe were more massive than the atmosphere it displaced, a lot of shoulder-to-shoulder dense microbes might increase atmospheric pressure. I conclude that these microbes are not that massive because by your description of them floating around they seem to be at least neutrally buoyant - equal in mass to the atmosphere they displace. So their presence should not increase atmospheric pressure.
Actually for a couple of reasons I think this black fog might make things colder. People argue whether [nuclear winter](https://en.wikipedia.org/wiki/Nuclear_winter) could really happen - enormous airborne clouds of black soot caused by fires cooling the planet.
from link
>
> This aerosol of particles could heat the stratosphere and block out a
> portion of the sun's light from reaching the surface, causing surface
> temperatures to drop drastically, and with that, it is predicted
> surface air temperatures would be akin to, or colder than, a given
> region's winter for months to years on end.
>
>
>
That is one mechanism by which the fog would cool the earth - trapping heat high up and preventing light from heating the earth below.
The other mechanism is that this colossal biomass of floating photosynthetic organisms would deplete our atmosphere of the main greenhouse gases we have - CO2 and H2O both of which are required for photosynthesis and which presumably this fog will gobble up, there being no other obvious carbon source or water source for them. Without those two, it gets cold.
<https://www.giss.nasa.gov/research/briefs/ma_01/>
>
> Without naturally occurring greenhouse gases, Earth's average
> temperature would be near 0°F (or -18°C) instead of the much warmer
> 59°F (15°C).
>
>
>
\*hard science term
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
Something is going to need to circulate the atmosphere, bringing the hot air trapped at the bottom of the fog to the top to cool off and bringing the cool air down.
Whoever created the microbes cracked open a bunch of volcanoes at the equator. They heat the air, causing it to rise and bringing up materials for the live microbes in the upper atmosphere.
Meanwhile, at the poles, the microbes detect that the local magnetic field is pointing down, turn white, and die. The white microbes reflect a lot of sunlight from the poles, making the air much colder. The cool air sinks, slowly making its way to the equator and cooling the land as it does so.
This makes the poles the most hospitable region of Earth, as the vast amount of falling microbes and cool air make it an ideal place to live.
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
There are three kinds of events that are similar yet not identical and that are said to reduce the temperature should they happen. [Impact winter](https://en.wikipedia.org/wiki/Impact_winter), [nuclear winter](https://en.wikipedia.org/wiki/Nuclear_winter) and [volcanic winter](https://en.wikipedia.org/wiki/Volcanic_winter).
What they have in common is that in all three cases at least part of the reason for the lowering of temperature are particles injected into the upper atmosphere. And that would be true for the scenario described in the question, too.
Based on that I'd post the thesis that the microorganisms in the upper atmosphere would block sunlight and by that reduce temperature, too.
**But:**
Biological [decomposition](https://en.wikipedia.org/wiki/Compost) creates heat and if happening on a big enough scale that can offset the reduction in temperature by the artificial winter.
How can this work?
Certain microbes are introduced into earth's eco system. They are light enough to float when you but get heavier over time when they reproduce. The old microbe starts drifting down, releases its seeds and dies.
After some time the microbes, having no natural enemies and a high reproduction, build a fog that covers all of earth. The temperature rises in the upper atmosphere and lowers down on the surface (as it would during a volcanic winter). The increased temperature speeds up the growth of the microbes, but the lack of light below the upper reaches of the fog speeds up the death of the mature microbes, too.
The dead microbes settle down at an increasing rate, creating compost heaps everywhere they collect due to wind currents. There they decompose in an exothermic reaction that, after some time raises the ground temperature back to levels similar to those before the introduction of the microbes.
Such a scenario would always be on the brink of becoming a planet wide [dead zone](https://en.wikipedia.org/wiki/Dead_zone_(ecology)). But surely the advanced intelligence who engineered the microbes in the first place would prevent that, no?
I'm not sure whether the citations about the various kinds of artificial winters and those about heat generated by decomposition of organic matter are enough that this answer is on topic but I think it gives an overview how such a scenario could work.
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
You just make the organisms not only very poficient a photosynthisis(which would cool the planet) but also others which use "thermosysthisis" directly converting heat to energy in the high atmosphere.
[Answer]
**This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information.
## How can I keep our world from turning into a Venusian hellhole?
You can't always get what you want.
Problems with your scenario:
1. **Black** fog absorbs heat, but
2. photosynthesis requires **green** plants.
3. What keeps *living* "fog" in the atmosphere, but allows dead "fog" to sink?
Not even a thick *green* fog would work, because -- sooner than you think -- all of the light will be absorbed and there will be no more photons left to power photosynthesis at the lower levels.
] |
[Question]
[
In constructing a composite or laminated bow, horn has a practical purpose.
>
> A thin layer of horn is glued onto what will be the belly of the bow, the side facing the archer. Water buffalo horn is very suitable, as is horn of several antelopes such as gemsbok, oryx, ibex, and that of Hungarian grey cattle.[3] Goat and sheep horn can also be used. Most forms of cow horn are not suitable, as they soon delaminate with use. The horn can store more energy than wood in compression.
>
>
>
In this alternate scenario, the horn of one other animal is being used in the process--that of the rhinoceros. The only problem is that rhino horn does not have a bony core--it's nothing more than compressed hair. So the question is: **Would rhino horn be a feasible ingredient in the construction of a composite bow?**
[Answer]
What horns are for sure suitable?
You need a horn that is keratin. You use it on the bow's belly due to its compression strength. If you look closely at images, like [here](http://www.mikedudleyweapons.com/s/cc_images/teaserbox_941435788.jpg?t=1440809185), [here](http://media.liveauctiongroup.net/i/18247/17604361_3.jpg?v=8D0999F6650EFB0) and [here](http://www.salukibow.com/attachments/Image/Hornbowbirchbark.jpg?1425057536824), you will see that keratin horn used on bows looks smooth, almost like uniform, molded plastic. This is because layer used is so dense, and keratin strands so close and so connected with each other that it will be really hard to break their bonds, aka delaminate.
If you will look at cow's horn, you will see layers and "strands" [image](https://upload.wikimedia.org/wikipedia/commons/8/88/Cow%27s_Horn_used_for_infant_feeding_Wellcome_L0036715.jpg), [image](http://maxpixel.freegreatpicture.com/static/photo/1x/Beef-Cow-Agriculture-Ruminant-Horns-Horn-Animals-1758361.jpg). These are not too strongly held together. Indeed you can break cow horn spoon just by washing it without caution. Seen it.
Now, about rhino horn. Look at images of it. Like [this](http://oxpeckers.org/wp-content/uploads/2015/05/Qiu-phot-1.jpg), [this](https://media.npr.org/assets/img/2013/05/06/rhinoivory4_wide-a56d338cda5c6a3a94e8553be858f9934cfd4d84.jpg?s=1400) and [this](http://www.vikingsword.com/vb/attachment.php?attachmentid=28204&stc=1). Strands and splinters are even more visible. On finished products it is more pronounced. While horn handles and bow bellies are usually shiny smooth, the best what you can do with rhino horn looks like [that](http://www.oriental-arms.co.il/photos/items/38/005438/ph-4.jpg), or [that](http://www.oriental-arms.com/photos/items/92/007092/ph-0.jpg).
This is not a definitive proof, but this sure look worse than cow horn, already found unsuitable.
Sadly, rhinos are endangered and their horns expensive, so finding actual measurements on them was beyond my capability. Also, if someone would be able to find a CC replacements for images I linked to, I'll be glad to include them. For now, this is the best I can do.
[Answer]
The bone part is not what is used in the composite bow; it is the outer keratin sheathe. Given that, there doesn't seem to be any reason you can't use a rhino horn, as its chemical composition will be similar to an antelope horn.
Deer 'horns' are actually bone, with no keratin at all; that is why they are not listed as a suitable material for the belly of the bow.
However, given that cow horn is unsuitable, and that is more or less the same keratin as the other horns, it is hard to say for sure that rhino horn would be suitable.
] |
[Question]
[
The planet in question is [this one](https://worldbuilding.stackexchange.com/questions/72840/sky-color-on-a-planet-with-an-atmosphere-consisting-mainly-of-nitrogen). Approximately three quarters the size and half the gravity of Earth, an atmosphere 25% as dense as the Terran one which mainly consists of Nitrogen with small percentages of Oxygen and Carbon Dioxide. Orbiting a Proxima Centauri, a red dwarf, at the outer rim of the habitable zone, the planet is relatively cold, with average surface temperatures ranging from -80 to -30°C. Volcanic activity is non-existent or minimal at most. The sky takes on a dark greyish-brown color, becoming reddish at sunrise and -set and during dusk as well as around the star.
The planet rotates within 27 hour; its orbital period is approximately 20 days. The orbit is rougly circular; the axial tilt of the planet is relatively high (34°).
Seas of liquid ammonia cover approximately half of the planet where it is not frozen. Color of the sea varies from deep blue to golden bronze, varying by the amount of metals dissolved in the ammonia. The colors render the structure of oceanic currents.
I have heard that ammonia quickly and easily dissolves soil, so I imagine that the terrain, especially the coastlines, would be very ragged. I imagine that ammonia would only boil or evaporate in few places and quickly rain down, which means that most rivers would be periodic and located close to coasts, albeit leaving distinct marks on the terrain.
The topmost layers of the rock or soil will probably contain nitrogen compounds, their concentration rising as you get closer to the nearest coast. This will be interesting especially if those compounds have distinct colors.
Terrain close to the coasts will be very ragged, full of small ammonia lakes or ammonia ice patches, canyons and valleys made by rivers while further away from the sea, it will mainly consist of plains and rolling hills with occasional meteorite craters.
Because ammonia does not have a density anomaly like water, I imagine that the further north or south you travel, the higher up the sea will be frozen. While only the deepest areas of the equatorial lakes and oceans will be frozen, the poles will be covered in vast and very flat ammonia sea plains and glaciers.
My questions are:
* Is my description plausible?
* If not, why? What must be changed?
* Can you add anything? Weather system? Climate? How would ammonia clouds look?
[Answer]
Your description seems plausible to me. I might add a few things which may or may not have been considered.
**Volcanic Activity**
Given that your planet has no volcanic activity, its core has cooled, leaving no magnetic field and leaving the atmosphere vulnerable to being stripped away by solar/interstellar winds. These winds will pick off the least dense elements of your atmosphere, so nitrogen will be a prime target.
**Thin Atmosphere**
With a thin atmosphere, you'd expect less weathering, meaning high mountains. With no geological activity, however, mountains have more time to be worn down. The terrain of your planet depends on how long ago your planet stopped being geologically active and how windy it is. I detail below that your planet is windy, so I expect the rolling hills and plains that you mentioned, even for a planet with half the gravity.
A thin atmosphere with mostly nitrogen also means no greenhouse effect, so your surface temperature is close to the effective temperature of the planet. The actual numbers are important, since I assume you want the ammonia freezing point to be somewhere within your temperature range: <https://en.wikipedia.org/wiki/Effective_temperature>
**Axial Tilt**
Your planet will experience more dramatic seasonal changes due to its high axial tilt. This puts your tropic latitudes at +/-34 degrees and your arcitcs' at +/-56 degrees. What this means for your weather:
* Bigger surface temperature range
* Lakes can actually freeze near the equator, since a summer at the equator will be *colder* than a summer at the arctic.
* Since your seasons are 5 days long each, you'll have a dramatic temperature differential, which is the source of most weather events on Earth. Very windy planet.
[Answer]
The emission spectrum of a red dwarf would be much different from that of our Sun. When you say
>
> The sky takes on a dark greyish-brown color, becoming reddish at sunrise
>
>
>
and
>
> Color of the sea varies from deep blue to golden bronze
>
>
>
do you refer to "our" colors, or to the local equivalent in the red-dwarf spectrum? Expecially blue would be hard to see, in a reddish light.
Furthermore, you state gravity is half the one on Earth, but yet you want to have a denser atmospehere. How? The density of the atmosphere is dependent on the gravity, in other word the stronger the planet can "hug" its gaseous blankets with gravity, the denser the atmosphere will be.
Lower gravity mean less dens atmosphere.
Last point, with lower pressure (due to lower gravity) how are you going to keep ammonia liquid? I have the feeling the temperatures and pressures you imply in your description gives only gaseous ammonia.
[Answer]
There may be some fundamental problems with this planet that supercede concerns about its appearance.
A terrestrial planet with half Earth's gravity and a quarter its atmospheric density would have a very difficult time retaining the hydrogen necessary for ammonia (NH$\_3$). Even in orbit of a weak red dwarf, your planet would be subject to hydrodynamic escape (consider Titan, 9.54 AU out, also experiences this) from stellar wind (Proxima Centauri has about 20% Sol's strength). The lack of significant volcanism also suggests an inactive core and therefore a weak magnetosphere, further exposing the hydrogen. (As hydrogen escapes the remaining nitrogen and oxygen will form nitric oxide (NO) and nitrogen dioxide (NO$\_2$) and nitrous oxide (N$\_2$O).)
As L.Dutch points out, the pressure and temperature range you've given has your ammonia oceans flash-boiling, reliquifying, and then freezing. Consult this [phase diagram for ammonia](https://www.wolframalpha.com/input/?i=Phase+diagram+of+ammonia), locating your temperature range and pressure near the bottom left. Raising atmospheric pressure to Earth-standard would prevent this.
This planet would also have a tougher time retaining heat to prevent the anti-stellar pole from completely freezing over and dooming the rest of the world to a Snowball situation – I doubt a 20-day year is enough time for winter ice to thaw before the next winter begins – and much larger polar regions means a larger share of the planet is going to freeze in darkness each season.
As for its appearance, unless there is life there won't be anything we'd recognize as soil, as that is a mixture of minerals and organic matter, but you would find sandy beaches and rocky shores as on Earth. Liquid ammonia's greater ability to dissolve minerals would make for steeper river valleys and estuaries that penetrate much deeper in land.
] |
[Question]
[
I'm effectively looking to change the 'Could' in this question to a 'what' or 'How'.
[Could higher land-based life exist on a planet with a pressure of about 1 MPa?](https://worldbuilding.stackexchange.com/questions/3484/could-higher-land-based-life-exist-on-a-planet-with-a-pressure-of-about-1-mpa/3485#3485)
I'm working on a story in which humans visit a planet with intelligent life present. This will be an ammonia world, with a comparable gravity to earths, but a larger atmosphere: say, 10 atmospheric pressures.
The humans will/can be wearing whatever is necessary to keep them alive (breathing apparatus etc).
I'm wondering what the effects will be of this atmosphere?
1) I read about heat transfer- is this going to a huge problem for any life or humans on this planet? I understand that the heat would be sucked out of the animals very quickly, maybe prohibitvely quickly.
2)what would it feel like for a human? like being underwater? and could humans potentially fly at this pressure (easily, with the aid of some mechanical costume?)
Also other considerations, like how sound and light propogate?
Sound will be a lot quicker, and I assume that the light level at the surface will be much lower (How much lower?) would sound become a much more important tool than sight for animals evolved on this planet?
[Answer]
**I read about heat transfer- is this going to a huge problem for any life or humans on this planet?**
No idea objectively. *Probably* yes.
**What would it feel like for a human? like being underwater?**
The intense pressure would certainly create a feeling of underwater experience on Earth. However, although limb motions would experience much higher levels of drag, that would be nothing like underwater slow-mo.
Without pressure reduction suits, a normal Earthly-human would get ear pains very soon, followed by nausea and headache. Also, the freely available ammonia in the atmosphere will have devastating effects on the eyes, the lips, the inner lining of the nose and other places with soft membranes. It would feel like taking a dive in an ocean of bleaching powder. Extremely displeasing and very dangerous.
**And could humans potentially fly at this pressure (easily, with the aid of some mechanical costume?)**
Yes. While flight (with the help of wide leather/metallic flaps, worn on arms and legs) would still take a lot of muscle power, it will definitely be possible to stay aloft. Flight, for humans, will take the effort of both arms and legs and will require muscle movement resembling swimming.
**Would sound become a much more important tool than sight for animals evolved on this planet?**
This depends, not only on the composition of the atmosphere, but also on the distance of the planet from its star, the luminosity of the star and of course, the type of eyes these creatures possess. For example, for an Earth-sized planet present at 1 AU from its G type star, there would still be enough light reaching the surface for normal vision (albeit the excessively bleaching effect of the ammonia atmosphere on the eyes).
My personal idea about the environment (I have not researched this in detail) is that the creatures will require a very sophisticated ear type to function well on this planet. Human and other mammalian ears would be picking up too much noise and amplified sounds all the time to function properly. Smart noise filtration would especially be required.
] |
[Question]
[
Because our moon is tidally locked with Earth, then the same half always faces the Earth regardless of where the Moon is in its orbit. As such, would a tidally locked satellite such as our moon (assuming it meets the criteria for an atmosphere) be able to have seasons?
I can see that if a satellite has a tilt like the Earth's and it orbits a planet orbiting a star then it would have seasons similar to how Earth does. But a moon that is tidally locked cannot do this as far as I can conceptualize. I'd love some clarification on this, thank you!
[Answer]
The reason why Earth has seasons in the way it does is Earth's axial tilt relative to the Sun combined with its atmosphere.
Earth's moon has a much smaller (about 1.5°) axial tilt relative to the ecliptic than does the Earth (23°). Thus its seasonal variations are much smaller. *Note that this is irrespective of the fact that Earth's moon is tidally locked to Earth!* The contribution of Earth to the Moon's heating is negligible.
In order to actually *notice* seasonal variations, there has to be something to smooth out variations on a shorter time scale. Earth's moon essentially (*but not completely!*) lacks an atmosphere, so there is nothing to even out the differences even between sunlight and shadow, let alone over time. If Earth lacked an atmosphere, the temperature swings would be equally brutal here despite Earth's 23° axial tilt.
**So what you need for a natural satellite to have some kind of seasons is a difference of insolation across its surface, which is usually caused by having a significant axial tilt relative to the *sun*, and a significant atmosphere to even out the extremes and thus make the seasons noticable against the noise of local temperature variations.**
Compare [Are there seasons on Luna?](https://space.stackexchange.com/q/3541/415) on Space Exploration.
[Answer]
Yes but not as extreme as the Earth's. The Earth gets some if its seasonal difference from its orbit taking it closer or farther from the Sun. This would still affect the Moon. However, the Earth gets more seasonal effect from it's axial tilt (look at Australia vs US/Europe). That would not happen.
So, there would be some effect but not a lot. You would probably get more of an effect from the fact that the lunar "day" is about 28 Earth days long. That would produce a pretty hot spot that will travel slowly around the Moon.
[Answer]
The rotation of the moon is strongly influenced by the Earth's gravity, in such a way as to make the axial tilt relative to the ecliptic constant at 1.5 degrees. (The direction the pole points in constantly changes to make this possible [[wikipedia]](https://en.wikipedia.org/wiki/Orbit_of_the_Moon#Inclination)) This is a very small tilt, compared with the Earth's (at 23 degrees) and so there is little variation in the amount of insolation that each hemisphere of the moon gets over a year or over a month. (This small angle allows for the craters near the moon's pole to remain in permanent shadow, and for water ice to be found there)
So our moon would not experience significant seasons even if it had an atmosphere. However, the "day" lasts for 28 Earth days, and so during the 14\*24 hours that the sun is above the horizon, each side of the moon is alternately heated, then frozen. I don't know of any modelling of the atmosphere of a planet with a slow rotation, but it would be unlike the Earth's. The Earth has convection cells (Hadley cells) that move energy from the equator to the poles. The moon may have convection cells that move energy from the sunfacing side to the dark side.
A tidally locked moon can have an axial tilt relative to its sun. So it would be possible for seasons to exist, however remember that a tidally locked moon may have a low rotation rate, that is likely to be more significant than the seasons.
[Answer]
The Moon would experience the seasons every ~27 days (depending on location and the lunar standstill every 9.8 years).
The logic for this argument is (assuming an atmosphere, i.e. widespread surface thermal transference and minimally discounting the intense semi-global storm systems):
During the ~10+ days of the cycle the Moon is closer to the Sun by ~240 thousand miles than the Earth, this **almost completely eliminates axis tilt and inclination as a viable season indicator**.
Due to tilt and inclination there is a portion that never receives Sunlight. This area can be equated to the polar regions on Earth, the the "atmosphere," if anything like Earth's, given the surface area (thermal mass) and reflectivity of the Moon's surface, a much more varied ground temperature versus air temperature than the equivalent polar regions on Earth.
The surface temperatures will most likely range from -160 degree F minimum (it will receive a lot of energy from Earth during the dark times + surface convection) to 200 degree F, with a very high probability of damaging wind storms Moon-wide constantly. Due to the small surface area and the thermal differences between the sunlit side and non-sunlit side.
[Answer]
Well it would have a two phase day/night cycle anyway which is like having seasons in that it creates variations mean thermal inputs. As the Earth/Moon system turns the Moon, as seen from Earth, is lit by the Sun by varying degrees, this is what creates the lunar cycle we know. Therefore the Moon has a Solar day that's about 672 hours long but it also goes through an Earth day cycle wherein more or less of the Earth is lit and therefore radiating thermal energy towards the Moon. Between them these two cycles are going to create a season-like variation in temperatures. You've also hit on the fact that the Moon will have axial procession in it's Solar day cycle which will create a longer seasonal cycle and of course there's the orbital eccentricity of Earth to take into account. With a larger primary world the thermal and light inputs from the world the satellite is locked to becomes more important as well as they do with greater distance from the stellar primary of the system.
Really it's not so much about whether there *can* be seasons as what kind and how much they influence the environment. The Moon has several sets of seasons all of which have little impact because of the lack of any atmosphere to acquire and store thermal energy.
] |
[Question]
[
Suppose the surface of earth is -349 Fahrenheit and survivors live deep underground dependent on geo-thermal energy.
They do farming in tunnels. They have enough energy (heat, electricity), fresh air (similar to the existing atmosphere, don't mind how for now) and water.
What kind of vegetables and fruits could they grow with artificial sunlight?
[Answer]
Anything that can be grown hydroponically could be grown in the tunnels. So just about anything. Probably not mangoes.
[Answer]
Ignoring how deep they actually have to be (much much deeper than 300m) , **they could grow anything**.
Without insects, anything requiring pollination will have to be done manually, making it immensely labor intensive, but apart from that they're perfectly fine.
The first generation could only be hydroponic-able stuff, but after a while they have enough organic waste for regular soil, removing the last limit for what they can grow.
[Sidenote since you want to shoot your planet out of orbit: Stone is a bad insulator, but there are enough theories about life on extraorbital planets, copy from them what is theorized to be insulating enough]
] |
[Question]
[
Is there an equation between the factor of Earth's gravity (the moon is (1/6)G) and how long a person can reasonably stay in that environment before returning to Earth would cause serious issues? Obviously humans would survive easier on a planet with say 7/8 of Earth's gravity or 10/9, etc, than something further on the number line like 1/8 or 5/3, which led me to my question.
---
Serious issues in the sense that they would need a cane to walk, or oxygen to breathe, a wheelchair, etc. Something that they used to be able to do on their own would need supplemental assistance because of the lack (or augmentation!) of gravity in the environment they spent time in. Is there a way to know the reasonable estimate before that happens?
[Answer]
Fortunately for you we have human guinea pigs being subjected to the horrors of low G enviroments right now. They're called astronauts for some reason.
**However**, tests have only somewhat recently begun (only about 60 years ago) and because of certain ethical concerns (*crazy, I know*) we haven't actually locked any humans up there for more then a few years at a time so **we really don't know** the full extent of what low gravity does to a person.
Though broadly speaking we can say that extended periods in such conditions would lead to sharply declining bone density, damage (probably permanent) to the eyeballs and optic nerves (caused by the eyeballs being flattened), general muscles atrophy, the immune system becoming dangerously dysregulated, increased iron in the blood, issues in liver and kidney function and reduced digestion leading to malnutrition.
There are most certainly many other things that would start going wrong physiologically that we don't even know about yet.
---
So in short, this may be difficult to believe, but while we do know that low gravity will screw in innumerable ways with the human body **we simply have no idea** how long one can stay functional in it, mostly because we've never waited to see (*because, apparently leaving the guinea pigs long enough up there until they start having disabilitating complications is "immoral"*).
] |
[Question]
[
Inspired by [this question](https://worldbuilding.stackexchange.com/questions/70788/how-could-a-submarine-like-vehicle-steer-and-propel-itself-in-a-superfluid/70794?noredirect=1#comment205082_70794).
Imagine a sea of liquid helium. Some people like to use submarines, but we've got a better plan.
[Jet-Skis.](https://en.wikipedia.org/wiki/Personal_water_craft)
Impeller pumps are used in jet-skis and can also be used to shift [helium around](http://www.barber-nichols.com/products/pumps/cryogenic-pumps/liquid-helium-pumps), so we'll assume that the motive power of the craft is dealt with and the internal components are built for the cold. We're also assuming that our own bodies are protected from the ridiculously low temperatures by a MK4 Plot-Device.
As we're not professional helium jet-skiers and possibly in quite shallow helium it may be involved in collisions with the iron-hard water that forms the coastline of our frigid sea.
The question is what hull material is strong enough, light enough and flexible enough to avoid becoming brittle in the extreme cold and easily sustaining damage?
[Answer]
I have several ideas on this.
# Materials exist in the Cold Regime
Things we consider solid at *our* normal temperatures lose any elacticity and ductility before getting down to 4[K](https://en.wikipedia.org/wiki/Kelvin).
But what about materials that *could not exist* at our temperature? As we found when exploring silicon-based life, direct analogs of organic molecules using Si for C would require cryogenic temperatures to exist. So it might be possible to design something that has enough bonding strength to hold together but not too much as to prevent all movement, **at 4[K](https://en.wikipedia.org/wiki/Kelvin)**. At significantly warmer temperatures the molecules would fly apart.
This could be true for both elastic (rubbery) and ductile (metal) materials.
# Material Withstands Being Brittle
A material may be too brittle, but it can still be very hard. If there are no flaws in the microstructure, it might prove very difficult to chip at all, and any chip you do make will be small spallations (the force only goes down as it spreads out). So a perfect crystal may be just fine in terms of strength.
There are also composite materials. If we can’t combine strong and flexible because there is nothing flexible, you at least still have a combination. This will still provide the effect that cracks can’t propigate farther than the breaking of one fiber. The material boundary will interfere with breaking forces, and even reflect the force.
# Avoiding the Brittle Regime?
The linked Physics post discusses the ductile-to-brittle transition
>
> Temperature sort of maps to time and information transfer. At high temperatures, particles/dislocations travel quicker and with more ease than at lower temperatures. Thus information (stress, strain, ...) travels through the sample. There is more time to move around and shift to try to alleviate the applied stress or strain.
>
>
>
So... do you know why diamond is a better thermal conductor than copper, even though it’s not a metal? [Phonons](https://en.wikipedia.org/wiki/Phonon). If *information* about the stresses could be carried off by electron density waves which amplify the actual atom displacements of the material, you can avoid super-brittle behavior.
Maybe that’s not true—but it’s an awsome handwave for a science-based not-dumb story!
# Phase Change
Ever hear of [nitinol](https://en.wikipedia.org/wiki/Nickel_titanium)? A number of years ago, *[superelastic](https://en.wikipedia.org/wiki/Pseudoelasticity) nitinol* was [all the rage](https://youtu.be/T86A8YFs-qo) for eyeglasses frames and watch bands.
How does solid metal seem to be *rubbery*? The stress causes a high pressure which causes a phase transition to a smaller crystal. When released, it pops back to the larger form!
So, the atoms don’t rip free of their bond positions and thus it is not damaged. Engineering this property into a material at 4K might be possible, not with a simple alloy, but with a complex material or even grains that act as a meta-material.
# Supermaterials
Remember [this Answer](https://worldbuilding.stackexchange.com/questions/29801/what-are-some-plausible-super-materials/29834#29834)?
Such low temperatures enable *super* effects like superconductivity, so maybe the solution is to take advantage of that. In my “plausible supermaterial”, tiny bits the size of mineral grains are held in place via flux pinning, overcoming the normal physical strengths of atomic bonds and making overextension *reversable* rather than damage.
The 4K temperature makes this *easier* to acheive, with today’s knowledge. You can get ductile behavior on the scale of individual grains, substituting the flux pinning for normal atomic bonds. Even if it doesn’t have the futuristic ability to fly the units back where they belong, a *simple* mass of this material will exhibit the ductile behavior of a room-temperature metal, with no accumulation of fracture growth or “work hardening”, even as the individual grains are very hard and brittle.
And that’s the answer I had in mind when I saw your initial comment on the subject: engineer the bulk properties using grain-sized units of normal matter, and superconductive effects between them to bypass the limitations in available atomic bonds.
[Answer]
Firstly, see: <https://physics.stackexchange.com/questions/130803/does-extreme-cold-make-everything-extremely-brittle>
A heated thermally conductive plastic would work, polymers can be designed to have a huge range of properties, including for cryogenic applications. They also tend to outperform metals in terms of density. I would expect this to still be more delicate than a normal jetski, but not to shatter if you tried to turn.
Bonus points, it will be warm enough to boil the helium and create a leidenfrost effect, which is actually going to be (fractionally) higher friction than helium, but also protect from capillary action covering the whole set up in a layer of helium. The downside of this is that in-taking helium is going to be a lot harder if most of your craft has to be above the boiling point of helium. I guess that's the right place to invoke another MK4 plot-device.
Either way, jetskis rely a lot on drag for steering, so you are going to slide around like an air hocky puck. I recommend directional jets for directional authority.
Source on plastics: <https://www.curbellplastics.com/Research-Solutions/Industry-Solutions/Challenging-Environments/Plastics-for-Extreme-Temperature-Applications>
[Answer]
Flexibility, or better resilience, is due, at atomic level, to the ability of the molecules building the material to being displaced around their positions without breaking their bonds. This accounts why plastic materials (made of long flexible spaghetti-like chains of carbon atoms) are more flexible than ionic crystals.
When you lower your temperature close to 0 K (and liquid Helium is around there), you are pretty much nailing the molecules of any material to their position, with any displacement resulting in breaking the bond between neighbouring molecules.
Therefore I am afraid that the answer to your question is: no material can remain resilient in liquid Helium
[Answer]
### It can't be done
According to [this answer](https://physics.stackexchange.com/a/130821) everything becomes brittle at 0K.
It also says dense materials tend to become very strong, needing a lot of force to break, however a dense material wouldn't help you as you'd have to build something larger. You would also need to make it even larger to compensate for the fact that liquid helium is one-eighth as dense as water.
*It wouldn't look like a jet-ski at that point, and having said that I don't think the submarines would work either as they would most likely sink to the bottom.*
The liquid helium would also flow up the jet-ski and freeze you to death and freezing any electrical equipment the jet-ski may have, resulting in you freezing in the middle of a sea with no way of coming back.
Long story short, don't venture into a helium sea.
] |
[Question]
[
I was doing research on the terraforming of planets with a solid iron core and no magnetic field and saw a few suggested ideas for starting a magnetic field on Mars that got me thinking.
Most of what I read suggested that if you could get a planet to rotate faster, the core temperature would increase and return its core to a molten state, restarting convection and generating a magnetic field. I'm going to use Mars for this example, but I'm looking to apply this to other planets as well.
The common solutions I saw were the following:
* Hit it with asteroids at the right points to give it some spin (could potentially destabilize orbits of Mars and other planets.)
* Slingshot asteroids or planetoids around Mars.
* Move a planetoid with a quarter of Mars's mass into its orbit to use tidal
forces to generate the kinetic energy needed.
I'm planning to go with the third approach in this setting, but had an idea.
Would a belt of asteroids with a total mass equal to one quarter of Mars's mass yield similar results on its rotation speed to a singular planetoid?
The thought is, instead of locating and moving an adequate dwarf planet into Mars's orbit and all of the energy required for that, redirect smaller asteroids from our asteroid belt into Mars's orbit over time so there isn't one astronomical upfront cost and money could be saved by reusing equipment on the next few asteroids. I'm imagining a group of automated reusable asteroid tugboats/pushers.
Or would that amount of energy and effort be better spent applied directly to the planet itself?
[Answer]
I would imagine that, the energy needed to perform this could be in wasted efforts. As Levallon stated, these small masses would or could end up bouncing into each other. Possibly sending the masses into the planet or out of orbit causing either the inverse effect or next to no effect. The main issue also would be that, you would have to figure a way to get the timing and trajectory of the masses perfectly so that anything along the same line of rotation is speed locked relative to each other so that they don't end up colliding. You would also have to calculate the trajectories perfectly so that they are EXACTLY on the same line. Any degree off, even minimally to a .0001 would, over time, cause the masses to go off path causing rotation that may not be optimal or even negative to desired effects.
Based on current known technology (not sure how futuristic this would be), it would take a lot of energy to possibly achieve this. The main issue would be finding a body of rock large enough to achieve this so that you only need 1 mass to orbit. Anything that would be large enough is more than likely already orbiting as a moon or you would have to travel the solar system to find an asteroid large enough to make it possible.
Then the logistics of dragging said body back to the planet and launching it so that it orbits fast enough would be also tedious. Even if the planet had a rock large enough already orbiting (but say not fast enough to do the desired results), accelerating it's orbit too fast in relation to the gravity pull could break orbit and now you are stuck with nothing. The other issue would be that, if you achieve maximum allowable acceleration on the rock, without it breaking orbit, there is a chance that this rotation is still not fast enough to achieve desired effects.
There are simply too many things that could go wrong for this to realistically be possible. Of course, you are the world creator and you can have these issues as a possibility to add suspense, but in the end you can choose the ending.
Something similar was asked here about 2 years ago [What would be best way to re-melt Mars' mantle and core to revive its magnetosphere](https://worldbuilding.stackexchange.com/questions/8832/what-would-be-best-way-to-re-melt-mars-mantle-and-core-to-revive-its-magnetosph) and you may want to consider following through this for possible answers.
[Answer]
I would think that you would need a single planetoid to generate the necessary tidal forces to achieve the result you're looking for. One place you might look further would be the tidal effects Saturn's rings on the planet. I suspect that they are negligible due to their uniform distribution ( well, as opposed to a planetoid).
It's an interesting idea though. Maybe you could redirect the smaller asteroids to orbit each other, creating an something of a "dispersed moon," an orbiting group of asteroids with enough combined mass to create tidal forces. Eventually the planet's tidal effect would alter their orbits into ring, so you'd have to make periodic adjustments to maintain it. The orbital resonances necessary to make a stable system might be pretty hairy, and there would always be a danger that one or more would collide or be kicked out of the system.
Just my thoughts.
] |
[Question]
[
[Cosmic rays](https://en.wikipedia.org/wiki/Cosmic_ray) are energetic particles coming from space that hit the Earth's atmosphere and produce a lot of [secondary radiation](https://en.wikipedia.org/wiki/Air_shower_(physics)) (some of which we see in visible light as aurorae). Would it make sense for an organism floating in the upper atmosphere, or even on the brink of space, to try and make this energy work for them, as plants do using the photons from sunlight to split water? Or are cosmic rays too destructive, or too unwieldy, or too sparse for such use? The question is not confined to Earth, of course, or to organisms similar to those living on today's Earth. I'm trying to decide if a microbial biosphere could live off cosmic radiation and its subproducts.
P.S.: [This post](https://worldbuilding.stackexchange.com/questions/36534/no-sunlight-just-high-energy-radiation) touches on some of the same points as my question, though I'm thinking more about a rogue planet far from any star-like energy source (i. e. no pulsars or black holes nearby).
[Answer]
I would say that yes, it's borderline possible.
The organism should be very resistant to ionizing radiation; a Universe that allows [*Deinococcus radiodurans*](https://en.wikipedia.org/wiki/Deinococcus_radiodurans) to exist would have little trouble in producing this new critter, even limiting ourselves to DNA.
The organism would of course need to consume ordinary matter to replicate; it would therefore find it way more convenient to (also) extract what energy it can from that matter. Actually it's likely that the capability of absorbing cosmic radiation would evolve from the former; the organism acquires matter and this interacts with cosmic radiation, supplying harvestable energy. Once this kind of matter is more and more incorporated into the new generations of the organism, it will "optimize" itself to directly take advantage of the radiation.
An organism could not begin directly using cosmic radiation, since to do that it would need chemicals and structures that would be already pretty complex. It would need to start from simple chemical reactions, and evolve to first defend against, then make use of the radiation. The most obvious evolution pressure line would be if the defense takes the form of some radiation-hardy chemical, which is transformed on impact generating much higher-energy compounds that would be initially disposed of. Afterwards, any mutation allowing to extract energy from such compounds would have an enormous evolutionary value.
This is not unlike what already happened to [radiotrophic fungi](https://en.wikipedia.org/wiki/Radiotrophic_fungus), which produce a special kind of melanin that is capable of harvesting energy from gamma radiations. It would be more difficult (!) for our hypothetic organism, in that cosmic rays are much more penetrating and energetic than gamma rays and therefore require proportionally more massive interception.
And, of course, the organism would need to live somewhere with *a lot* of cosmic rays.
One possibility would be some sort of low-temperature outer space slug capable of accreting a "black ice" carapace. It would migrate to the safe center of cometary nuclei to spawn, then come out when the carapace is thick enough to both defend the young slug and supply it with energy. The slug would need to have a very low metabolic rate, and be based on a totally different organic chemistry than Earth organisms.
---
There's something along these lines in ["Camelot 30K"](https://en.wikipedia.org/wiki/Camelot_30K) by physicist Robert L. Forward, where a (macroscopic) lifeform is presented that harvests atomic nuclei transmuted by the impact of cosmic rays on distant comets.
>
> *"The initial energy source for the kerac civilization comes from the background cosmic radiation, which creates long-lived excited molecules and free radicals in the ice over long periods of time"*. He drew an arrow leading to another box that he drew in the rotund shape of an iceworm. *"Out on the farms, the iceworms and young heullers tunnel through the untouched ice around the periphery of Camalor. They extract free radicals frozen into the pristine ice and use them as a source of energy to grow and continue tunneling. Those long-lived free radicals are the first level energy source of the kerack food chain, since the iceworms and heullers are harvested as meat. While the iceworms are doing that, they also extract from the dirty ice all the unstable radioisotopes that the dirt and ice contain."*
>
>
>
(While different organisms are named - *iceworms*, *heullers*, *keracks* - it is posited in the book that they are actually all alternate phenotypes of a *single* organism, the kerack hive drone, not unlike what happens with bees).
[Answer]
Cosmic rays might *first* affect some non-living substance, which then provides energy and/or nurishment to the life.
That might indeed be a critical factor, like fixing nitrogen for the base of the food chain.
These cosmic rays can cause chemical reactions or nuclear reactions, such as 14C on our planet. So it could be a complex cascade of reactions, bringing energy down into the biosphere.
[Answer]
## It can't exist and this is why
This organism would have to be unlike any that lives on Earth. First of all, if the organism was in our upper atmosphere it would be too protected from the cosmic rays for sustainable life. If it has DNA, it would have to be very protected in order to prevent defects and damage. We're talking some kind of biological space suit as it were. All life that we know of has some kind DNA so this is pretty much a given.
Another factor is the distance between organism and producer of the cosmic rays. Obviously the further, the more sparse and unreliable it would be as an energy source, too close and it might get incinerated. Just like Earth, I suggest some kind of Goldilocks Zone where the conditions are 'just right'.
All this being said, I would assume the organism also needs some kind of respiratory system, and a way of excreting unwanted gases, because there isn't any thing that can survive from nothing but charged particles.
To conclude, I do not believe this is possible because the organism needs to be able to absorb harmful cosmic radiation with out being harmed. It also needs to be outside of a planet’s magnetosphere whilst still being able to diffuse with gases.
] |
[Question]
[
I'm looking to devise an extraterrestrial parasitic organism that perpetuates itself by infecting entire stellar biospheres before moving on to colonize other inhabited star systems. This organism would be a very well adapted interstellar apex predator.
The concept is inspired by the *Halo* franchise's "[Flood](https://www.halopedia.org/Flood)" species, but is intended to be much more fleshed out and within the realm of hard science fiction.
The parasite seizes control of the body of a host and utilizes every means and resource at its disposal to make the host a maximally-efficient vector for transmitting the pathogen to other potential hosts. This includes hijacking the host's nervous system to influence its behaviors (similar to what [Cordyceps](https://en.wikipedia.org/wiki/Cordyceps) does), and converting the host's natural cells into the parasite's dynamic cells, giving the parasite the ability to cause the host to undergo massive anatomical/physiological transformations (sometimes very rapidly).
Hosts will be able to communicate using pheromones to coordinate group action and inform the parasite how to behave at different stages of the epidemic (e.g.: not to make itself too obvious at first until it has a strong foothold over the population, etc.), making them an effective [swarm intelligence](https://en.wikipedia.org/wiki/Swarm_intelligence).
Eventually, when enough of a sentient population has been subjugated, many sentient hosts should converge to form a [gestalt, group mind "brain"](https://en.wikipedia.org/wiki/Group_mind_(science_fiction)), capable of applying higher reasoning and tactics to its cause of infecting as much as possible with maximum efficiency. At this point, the groupmind and all of the hosts within its range effectively become a [superorganism](https://en.wikipedia.org/wiki/Superorganism). The groupmind would broadcast its directions to the infected population telepathically (using the EM method depicted [on this thread](https://worldbuilding.stackexchange.com/questions/495/how-do-creatures-with-a-hive-mind-communicate/510#510), which brings me to question #3 in my list below).
When everything in the groupmind's reach (typically a star system) has been completely subjugated, assuming the groupmind has achieved sapience and has the resources of a fallen interplanetary civilization at its disposal, it would then devise a way to colonize as many other star systems as possible (with priority on the star systems that seem likely to have life, particularly sapient life).
I'm looking to maximize the virulence of the parasite, as well as the plausibility of the concept.
It must be able to exist within a hard science fiction setting: no FTL travel, humanity is confined to the Solar System (and for the most part, just Earth). I've considered the fact that the lack of FTL travel is a hindrance on the parasite's ability to jump between star systems (given that it can't just hitch a ride on an FTL ship), but it could hitch a ride on a sub-light speed ship.
My questions/problems are:
1. What should the infectious agent be (e.g.: bacteria, fungus, virus)? Would the copious amount of DNA that such a well-adapted creature would require fit inside of the infectious agent?
2. Flesh out the mechanisms behind the parasite's functions, including its neurological hijacking ability and its ability to rapidly transform a hosts body. Point out any specific obstacles and/or physical impossibilities with these processes you can identify.
3. Would the parasite be able to acquire and integrate enough metal into its host's nervous systems (or even the nervous systems of only certain hosts, such as locational nodes) to facilitate telepathy? If not, are there any other ways to create centralized groupmind? If not, are there alternatives to this groupmind?
4. How should the groupmind's colonization protocol work to maximize the likelihood of landing in a star system inhabited by a sapient, spacefaring civilization that its offspring will then be able to launch its own colonization effort from?
5. Any issues with what I've described above?
6. How might such a species evolve?
[Answer]
This is a really excellent idea. One that is quite thought provoking - and would be very interesting to read as an extended storyline - from either perspective (That of the host OR the parasite!)
To answer your questions:
1. There are many possible directions to take the infection vector. Three I can think of off the top of my head would be: a] A virus b] A small but incredibly tough highly complex carrier parasite - along the lines of a [Tardigrade](https://en.wikipedia.org/wiki/Tardigrade) c] Spores from a fungus
All of these have the advantage that you can easily describe them as entering a "dormant" state which you could posit as being able to survive the extremes of space. The one that I would select if I had a lot of "room" in my story (eg multinovel series) would be something like the Tardigrade, as a part of the lifecycle of your parasite. This would allow for a massive DNA payload. To explain it properly would take a lot of words - whereas a Virus or fungal spore would take far less words - so if I was only writing a single story or book I would take the simpler route.
2. I'll make a few suggestions for how I might handle certain aspects of the more complex Tardigrade vector. I would use the Tradigrade as purely the transmission vector. When it reaches a viable host (any creature that has a water based lifecycle) It can enter the host and break into individual cells. These are then transported throughout the host system - and once these cells reach particular kinds of cells in the host (which I probably would use axons) they would very gently insert themselves. The reason for using Axons is this allows the host to continue to function - until the colony is ready to completely overwhelm the host but also allow the colony to communicate. They would observe and release signals of their own until they began detecting signals from other tradigrade cells. Once they reach a certain critical mass of signaling - they begin to adjust the signals of the host slightly - over time obtaining greater control over the host - until they can begin completely changing the host actions to serve the needs of the greater colony. Once they achieve full control over the host - they would then move to the next stage - releasing colonising cells which are now targeted for each type of cell in use by the host. This will complete the colonisation process allowing the newly colonised host to become part of the superorganism. This is the point at which the process becomes irreversible. I would have the reproduction component of the cycle be on the expiration of the host - with the death of the host causing the host body to create millions of Tardigrade carriers - to then be sent forth.
3. I don't know why the Colony or host would require metal to facilitate telepathy - I would have the colony achieve groupmind through a mechanism of quantum communication - effectively once being able to "switch on" the quantum communication plugging the colony into not just the other colonies on the local planet - but all the other colonies in the galaxy at the same moment. This will give the ability for massive superorganism status and God like intelligence - Entire planets of sentient creatures could be focused on a single hard question. This quantum communication should be part of the DNA payload of the transmission vector - but should require a massive increase in the number of cells - and possibly some kind of specialised organ - this would happen/ be created as part of the total colonisation of the host. This should have some preconditions for success and be capable of failing - this would give a bit more interest in plot development. Maybe failure creates a second class colonised host? Maybe failure causes the die out of the colonisation attempt and a host that "escapes" colonisation - creating an individual who tries to stop the colonisation of others?
4. The Superorganisms colonisation protocol might depend on sending it's transmission vector to every possible location - regardless of suitability/ Sentience. Or more probably be directed by the superorganism to identify suitable target systems to send the infection vectors to. Once the quantum communication organ is activated - the superorganism will then direct all local hosts/ colonies in how to identify new vectors to send it's "Tardigrades" on slow journeys to ensure expansion new directions. It will direct creation of automated "probes/ drones" that are sent out to new stellar systems and is programmed to identify planets that are in the [Goldilocks](http://science.howstuffworks.com/other-earth1.htm) zone. Or perhaps the SUperorganism will identify suitable planets through Advanced tech - maybe by having the local civilisations create a massive space based telescope with a huge array of mirrors that enable it to actually look for planets better than anything we currently do. These probes/ drones can carry billions of Tardigrades in dormant mode for infection of the new system. Because thay can exist for centuries or even millennia in dormant mode - they don't need FTL to make it to another system. They simply need solar sails and time...
5. Are there any problems with what you propose - no not really - at least IMHO. You just have to make the story interesting - you need to write relateable characters and you need to have the right amount of conflict. Possibly your conflict can hang on stopping the infection - possibly it can hang from the POV of the superorganism in overcoming a particularly troublesome new group of hosts that are naturally resistant...
[Answer]
1. **Use an adapted virus as a carrier.** Viruses literally live (if you consider them alive) to enter cells and change the way they work in order to reproduce - exactly what you want! Meanwhile, bacteria and fungi are significantly slower, and require more complex parts; they may be significantly easier to quarantine. Just shove all the complexity into the genes of a virus; if it doesn't fit, make it larger.
2. ***No two aliens are the same*, so neurological hijacking and rapid transformations cannot easily be accounted for.** Life on different worlds [may not use DNA](https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry#Non-carbon-based_biochemistries), it may use use [solvents other than water](https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry#Non-water_solvents), or it may just live in something toxic to the invaders but not to itself.
* **While it's true** that DNA is very likely to occur, and that water is common - so a lot of life should be easy to conquer - you cannot expect cellular organization or safe chemistry that you can work with in every species.
* **Even if** the hosts have DNA, they're non-toxic, and they have cells just like ours, their brains may rely on different chemicals - or they may be organized differently - and their organ systems may be completely different - so a virus cannot simply go in with a single set of genes and expect to get the job done.
* **A possible solution** could include examining potential planets ahead of time before colonizing, though this is difficult - and the results may not be promising.
3. **Say goodbye to metal-based telepathy.** The parasite would need to
* (1) Control the individual enough to find "food"
* (2) Distinguish metal from other materials
* (3) Find a metal the host isn't alergic to
* (4) Determine quantity of metal necessary to generate microwaves for that particular individual
* (5) Acquire that much metal
* (6) Help the host digest it safely in a short span
* (7) Learn how the host's body transports nutrients
* (8) Move the purified metal to the brain
* (9) Learn how their body builds microstructures, or learn how to assemble them safely in that particular organ
* (10) Trigger the processes identified to build the structures
* (11) Rinse and repeat for every individual creature involved in telepathy
* (12) Use the machine
* (13) Avoid damaging the brain tissue when its turned on
Even if all of the above steps were possible, you'd need to be able to fit that much computational power onto a single virus.
**Consider having the virus itself acquire metal and transmit signals.** It will be larger than a traditional virus, but much, much more reasonable.
4. **Compared to the biological aspects of this species, identifying host worlds is a piece of cake.** If group minds are `capable of applying higher reasoning and tactics to [their] cause of infecting as much as possible with maximum efficiency` and they start out with spacefaring species, surely they can use those species' technology to locate other intelligent organisms.
5. **After you cover the logistics of infecting diverse aliens and facilitating change, I think you're all set.**
[Answer]
Ever seen an bacteriophage?
How about a Planetophage?
You need a virus: small constructs that have dna in it.
You will have to use ribozymes for the following function:
1. make nucleic acide from molecules in it's environment.
2. replucates and transcribes dna or duplicates rna(the ribozyme itself)
3. burn organic material for energy.
4. makes coponents of an interstellar spaceship, then launch it away.
Rna origami involves the assembly of
1.any polygonal model of the stl or obj format.
2.any 3d shapes that consists of voxels, with minimal effort, by the base pairing of rna nucleotides. It is, therefore, possible to make spaceship parts with rna.
For the brain, use a DNA biocomputer: logic blocks binds to do logics and/or find the answers of a certain question.
Make some small magnetite crystals, and place them on the output of your biocomputer, actuated by molecular motors and/or acruators(to wiggle or spin rapidly, radiating radio waves) as a form of radio, for sending instruction to
your infected drones.
For the reason why this needs a biosphere to survive, it is mostly because that there is no effective form of energy generation, other than organic chemistry reactions by pre-existing organic molecules, with ribozymes alone, therefore, it needs a feedstock of organic chemical in a suitably favorable environment for combustion to replicate or do things, which means, a viable biosphere.
Your phage's life cycle will look like this:
First, adhesion and injection: the alien spaceship, or Capsid, crashes down on the planet of your choice, surviving atmospheric entry by a thick ,ablative hull.
Second, internal release: infective agents, with a integrated pore forming molecules, leaves the now broken hull, and they finds a cell, burrow into it, and releases it's contents.
Third, replication and transcription: once inside the host cell(s), the infective agent burns the readily available organic molecules, manufactures nucleobases (or using the host's own processes), and starts to replicate and transcribe it's detailed genome. multiple parts of the genome would be in separate packets(to reduce size and improve agility) and will cooperate.
Fourth, spawning: the active phage genome now transcribes different RNA parts for various purposes, including new infectious agents, vehicles for resource gathering and transport, etc. after all, biology is just advanced nanotechnology that can replicate itself. The rest is just Plague inc. gameplay. After a few months, the phage would have hijacked the planetary biosphere to produce it's own parts, and the spawning begins: from nanoscale to macroscale, billion of RNA parts self-assemble in an orderly and methodical fashion, building multiple new spaceships, each have it's own biocomputer, each packed with the phage DNA genome, each can infect another planet and repeat the cycle.
Finally, lysis: After the assembly of new Capsids and the packing of the copies of tha phage genome, The large biocomputer "Brain" of the infection now uses detector structures to look for other planets with a suitable biosphere, then send the ships en route. As this requires a massive amount of energy, all remaining host would be burned as fuel(to provide electrical energy for, as an example, a laser drive base station), completely sterilizing the planet, consuming all the biosphere.
Now, the new duplicate phage Virions fly off and land on other planets, starting the cycle again.
[Answer]
Virus would probably the best bet since they can actually change the DNA of the host. Perhaps it could be a superior kind of virus that has multiple sets of DNA. One that it uses to infect its host to a zombie like state that is internally defenseless and the other for itself since it obviously wouldn't want that DNA. A bacteria or fungus couldn't "force" the body to its will. It would be cool if the virus's dna inside the host's nucleuses gave the host strong instincts(like an inner feeling or need) to protect the virus at all costs. So the host will still be in control but be trying to do protect the virus inside him at all costs even if it means killing his own kind as well as giving instincts to wanting to spread the virus. Multiple hosts could even have the urge to conspire to spread this virus. No telepathy would not be possible. Perhaps if you want you could have an infected scientist make brain computer chips that allow infected hosts to communicate through bluetooth or one of the satellites of the planet it is infecting. You could always have the virus make the host release certain pheromones however. These wouldn't allow the infected hosts to communicate ideas over long distance, but rather feelings short distance. Like when a host enters a building it would be able to tell that another one of the hosts are in trouble somewhere in the building. Anyway this idea would work pretty well I think. If each host is separately infected and still thinks independently instead of as a huge zombie like mass, they would have a better chance of spreading the virus. Being different will allow each person to help bring a new skill set to the table to helping spread the virus and saving the virus species.
[Answer]
You could call the parasite Y. A simple stretch of DNA which does not do much until host maturity, at which point it hormonally hijacks the nervous system, compelling an amazing variety of persistent efforts by the host to mate with conspecifics and produce new individuals, half of which would carry the Y and the other half capable of gestating new individuals with the Y. At critical mass the Y carriers band together and devise a system leveraging language, writing, and religion called "culture" - this to control the necessary non-Y individuals (because the Y infected cannot gestate new individuals). Armed with culture, the Y infected form a superorganism called "society". The society of Y infected have the side benefit of wiping out or subjugating other life forms on the planet, and indeed altering the very surface of the planet maximizing the carrying capacity of the planet for Y.
[Answer]
I don't see something like this evolving though it certainly could be designed.
Bacteria amoeba virus fungus. Those are categorized based off naturally occurring life. Some bacteria are photosynthetic, fungi tend to eat dead things and form a symbiosis with plants, amoeba are just weird, and viruses are too simple for complex programming. A synthetic organism doing this wouldn't really fit into an existing category. Just remember that evolved cells are naturally occurring microbots. The below is basically biological utility fog in the micrometer range instead of the nanometers range. Though microscopic cells still have nanoscopic organelles. Every cell is by default a molecular 3D printer. Viruses are not cells because they cannot self replicate. They are obligate intracellular parasites that hijack the replicating hardware of actual cells. I'm not sure how to make an interstellar virus due to a viruses very small size and limited programming capacity.
For interstellar travel have it form into giant space whales that uses sunlight up close and radioisotopes in the deep interstellar void plus reaction mass. Slow but effective.
If they are intelligent enough they can create stellar lasers for thrust energy and communications.
Metals are not needed for radiotelepathy. Sure alkalines like magnesium and potassium could be used as ion pumps, but hydronium ions could also be used.
When landing on a planet it would go into or orbit, decel using the planets magnetic field or solar wind, powered by sunlight, then break into smaller chunks and decrease it's density to slow down aerodynamically.
It's attracted to the electrical stimulation of the nervous system and kills the organism soon after infection, but do to it's landing method it gets dispersed in the air and water so infecting more won't be an issue.
I suppose the act of neurodegeneracy could make the infected temporarily behave as zombies maximizing the local rate of infection before host death. Then consume all the biomass of the various hosts, basically all life on the planet, then grow a tethered ring to launch into orbit,reform into space whales, and move on.
Forming into mega telescopes will let it see very high resolution images from dozens of light-years away so that it can plot a course.
Such a creature wouldn't actually need to eat life, just the materials that carbon based life is made of. It should also envelope asteroids and digest then when enough sunlight is available.
We do not currently know if artificial gravity, or gravitational repulsion is possible. If it is then maybe it can be done organically. Maybe dark energy can be harvested.
If it can be done organically then getting in an out of a gravitational well would be much easier, and it would harvest dark energy all along the path towards the next host.
But solar power/ radio isotope powered shape shifting sapient spacewhales using reaction mass to very slowly travel interstellar space most certainly is physically possible. It would have to be designed and it would be a very slow trip.
Maybe organic low energy nuclear reactions are possible? Nobody knows yet.
Some answers are better then mine but that's what I've got.
] |
[Question]
[
**I am looking for a mechanism that would cause ovum containing a specific allosome to degenerate before they could form a zygote.**
More detailed background: I am trying to design a unique method of what [I learned](https://worldbuilding.stackexchange.com/questions/65238) is called diploid arrhenotoky. Males and females are both diploid, but males are only produced parthenogenically.
Arrhenotoky produces diploid females and haploid/parahaploid males, not true diploid males. Haploid individuals can't carry two alleles and that complicates Mendelian inheritance.
The Z/W or Z/0 system works differently: ZW/Z0 zygotes become female, ZZ zygotes male; male produces Z sperm while female produces Z and W/0 ovum or ZZ and WW/00 (non-viable) zygotes under facultative parthenogenesis.
The only way I can think of to keep male zygotes from being conceived sexually is to make them non-viable somehow... I have no idea *how* to keep Z ovum from becoming viable.
[Answer]
In biology weird things happen. For example, many animal species and *very* many plant species are tetraploid, hexaploid, octoploid etc. In plants it is even common to have the species of a genus share basic genomes combined in various ways; for example see the [Triangle of U](https://en.wikipedia.org/wiki/Triangle_of_U) which interconnects the members of genus *Brassica* (cabbage and rapeseed), or the [genetics of wheat](https://en.wikipedia.org/wiki/Wheat#Genetics) (*Triticum*). So if the species is tetraploid, hexaploid or octoploid the "haploid" males will be diploid, triploid or tetraploid and could carry two, three or four alleles for each locus.
As for the mechanism of rendering the sexually-conceived ZZ deleterious you could use an almost imperceptible handwave and say that a Z ovum cannot be fertilized by a Z spermatozoon due to [cytoplasmic incompatibility](https://en.wikipedia.org/wiki/Cytoplasmic_incompatibility).
And Mendelian inheritance is overrated anyway.
] |
[Question]
[
To My Valued Fellows,
As we are all aware, our people have made tremendous progress both evolutionarily and technologically. Thanks to us, [our species](https://worldbuilding.stackexchange.com/q/33040/6986) is protected from the ravages of cancer and we have developed the means to fabricate any product we may desire. Combined with our latest invention, allowing us to move between dimensions and so effectively eliminate travel times, our society has achieved an unprecedented level of perfection. For this, I must congratulate you all.
However, I must also bring to point the dark side of our developments. [Our world](https://worldbuilding.stackexchange.com/q/33603/6986) is dying. Overpopulated and under cared for, my analysis reveals that, without major corrective action in the next few centuries, just a handful of generations, it will cease to be habitable by even those in our species with the hardiest of genetic alterations. As has been the case for millennia, it falls to us to safeguard the future of our species.
Our people are unwilling to change their ways, so we must ensure their compliance. I propose we employ a species-wide modification that is [slow-acting enough](https://worldbuilding.stackexchange.com/q/62055/6986) to prevent our people from realizing what is happening. This will safeguard our work long enough to make the changes irreversible, no matter how much anger is directed towards us and our purpose.
I have already begun work on a virus that will enable our world's flora to control a certain small, planet-wide species of bloodsuckers. However, **I am asking each of you to devise and propose a mechanism that can be deployed via the bite of this insect and will initiate and further a slow, nonlethal genetic change.** Be open to criticism on your idea, as they will be discussed at length come the meeting at the hibernal solstice. The mechanism that is safe, efficient, and hardest to notice will be implemented.
Once our kin are too far gone to offer reasonable resistance, we will be free to dismantle the modern structures. The world will heal itself and our species will be safe.
Sincerely,
*Myrissar E'dan Wudende*
Chief Officer of the Future
P.S.: Make sure to enjoy the hibernal celebrations this year, and come to the meeting prepared to discuss any specific genetic changes you want for yourself.
[Answer]
If I understand your question (in bold) correctly, you are only interested in how to make a vector for an agent of genetic change, not what the change should be or how to ensure exposure of all the planets population to the mosquito-analog, correct?
In this case, the mosquito analog needs to have a renewable cell culture that can harbor your genetic virus, but allow the virus to pass into the human host. So the virus can be shed in a saliva compound that coats the proboscis (basically inoculating each human during each feeding) or resides in the analgesic compound used to numb the human to the effect of the bite or anti-coagulate to assist in blood flow. This way each feed infects the human.
You want the mosquito to harbor a "clean" source of the virus so that you get the desired change each time. It is likely that the virus will mutate once it gets into a human host and undergoes billions of replications within all the cells, but so long as the mosquito can't pass this mutated form of virus to another human each infection will start with the "pure" viral strain. So you want to make sure that the mosquito creature can't itself be infected by the mutated virus and start to infect humans with this altered form. Every bite has to give just the pure virus, nothing else. Granted, the virus is replicating inside the mosquito creature as well, but with just a small cell culture organ and a short lifespan there shouldn't be as much of a risk of the virus mutating within the bloodsucker itself.
Edit- Additionally, you wan this change to be slow. One solution is to have a two stage process. Stage One is the mosquito-analog delivered virus for gene therapy. BUT this alteration, but itself, is silent, it does not affect the organism. But once you have affected most of the population, who are unaware of the change since it has no apparent effect, you then release a SECOND stage that activates the newly inserted gene. You can do this via inserting a second upregulator gene, altering the epigenetics to begin expression of the newly encoded protein, adding a new substance into the population food supply that activated the new gene's products, or even add a prion protein that reconfigures the harmless new protein made by the new gene into the bioactive form that gives your desired effect.
This way the population has already been altered, they just don't know it, and you can control the activation of the secondary stage in a more manageable fashion (since waiting for mosquitos to bite everyone is gonna be a LONG process).
It sounds like you want some type of neurodegenerative process that strips away higher levels of intelligence, or at least blunts ambition, greed, and innovation, making your population more passive, docile, and less prone to hoarding material goods. Shouldn't be too hard to do this without impacting the health and well-being of the organism. But dial it down to far and you will have to do some serious modifications. We can no longer survive without tool use, clothing, etc unless the environment is just right.
[Answer]
I would say that you need something very precise to prevent harmful genetic mutations. Nano-scale robots programmed to modify the DNA of the [germline](https://en.wikipedia.org/wiki/Germline) cells, rather than just the somatic, passed by mosquitos.
[Answer]
Dearest Fellows,
## Simply stated, this is impossible.
Survival is the utmost concern for our population, so there is **no real way to hide a change this drastic** from everyone. First and foremost, other groups will **take notice** of our actions to infect insects. Next, those receiving routine gene alterations will **decide to improve** upon their genetic structures when they are inferior to distant ancestors, and peers in un-infected regions. Most importantly, this new disease which changes our genetic makeup will very clearly be **seen as a threat to society**, and eliminated; its lack of hostility means it won't combat vaccination efforts in any way, and direct intervention on our part will inevitably cause suspicion.
People will notice us, and punish us, because there is **no feasible way to hide a change this drastic.**
## Even if we are't detected, we will leave future generations vulnerable.
**Extinction Events**
I know that some of our associates have proposed foreign pathogens, and described ways in which they may be designed to have the best possible effects. **Even in these scenarios,** the reduction of our *proud race* to an animalistic carnivore will be **detrimental to our continued survival.** Events such as the [Late Colossal Terran Extinction](http://www.bbc.co.uk/nature/extinction_events/Cretaceous%E2%80%93Tertiary_extinction_event), which eliminated most of our complex, land-dwelling ancestors, and the [Pre-Quarternary Mass Extinction](http://www.bbc.co.uk/nature/extinction_events/Permian%E2%80%93Triassic_extinction_event), which eliminated 96% of life on our homeworld, will undoubtedly occur regardless of how we change society. **Regardless of how we shape our evolution,** we will remain, to a degree, vulnerable to these disasters.
**Unfitness to Survive**
Normal evolutionary pressures will be active once the population becomes primitive. Even if we Fellows keep or improve our current genetic codes, we will lose the infrastructure and technology allowing us to impact the global population - evolution will take the reins, and we may not be able to catch up. Therefore, our newly created, dehabilitated mixtures of monsters and men will have to fend for themselves. We cannot help them, and, unless we preprogram everything necessary for fitness, they may not be prepared to return to the wild.
**The World's too far Gone to Abandon**
While we may like to rely on clean energy, you point out that our world will lose habitability in a few generations. **Even if** there is a logistically feasible way to infect the population, and **even if** realization is out of the question, we will be leaving a polluted world for these creatures to inhabit. After infrastructure collapses, power plants decay, and high-maintenance factories are unmanned for too long, we will release toxins into the areas we inhabit as a species.
It's worth noting that if our solution to pollution is removing the polluters, the **pollution will still be there where we left it.**
## Additionally, there is no feasible way to effect our breatheren on other planets or in space.
**And finally, altered individuals would not reproduce with unaltered individuals. Therefore,**
## We are crossing the species line.
Instead of keeping our kin alive, we are dissipating our society into something engineered in a lab and unlike them. It's worth asking if this is "the survival of our species" or the end of a proud race due to a powerful madman's machinations.
*Fellows, I beg you.*
Do not allow this scheme to continue. It will be stopped **dead in its tracks** due to reasonable opposition, and even if we eliminate the opposition, it is a **logistical nightmare** that will **end our species** as we know it - potentially for good.
Urgently,
*Adelaide Baradotzi*
Keeper of the Peace
---
P.S. If the opposition is not as strong as I suspect, perhaps some of us can migrate and be altered, while others may remain and clean up the planet through traditional reform and efforts. If one fails, the other may still succeed. It's worth working out the details, but note that if the altered population gives consent, there is **no need to diffuse our genes** - simple modification will do the job (and answer your question in full).
[Answer]
# I am afraid that a virus would not work.
Viruses work by getting in a cell, changing the Database of New Amino acids (fine. I *know* that is not what it stands for, but it is what it does) so that the cell manufactures new viruses, and *not* the necessary amino acids. It They then escape the cell that made them:
>
> Release – Viruses can be released from the host cell by lysis, a process that kills the cell by bursting its membrane and cell wall if present
>
>
> (Source: wikipedia: virus)
>
>
>
True, you can also use "a lysogenic cycle where the viral genome is incorporated by genetic recombination into a specific place in the host's chromosome."(wikipedia). However: "at some point, the provirus or prophage may give rise to active virus, which may lyse the host cells."(guess! yep, wikipedia).
## Conclusion:
You need a completely alien sort of harmless pathogen. Earth viruses don't do what you want.
] |
[Question]
[
I've seen some articles about biologically powering devices through a [glucose fuel cell](http://news.mit.edu/2012/glucose-fuel-cell-0612), but from what I can tell this would only provide power on the order of a few tenths of a watt.
While it's definitely an interesting scientific development, it probably wouldn't be ideal for powering something like a sixth-generation Intel i5/i7 NUC computer, which can draw [between 38 and 77 watts](http://www.anandtech.com/show/10343/the-intel-skull-canyon-nuc6i7kyk-minipc-review/7) under high load and approximately 17 watts when idling.
That being said, suppose there is a near-futuristic race of mammalians that have a computer of similar caliber implanted in their bodies. Consider that:
* The power source shouldn't be implicitly fatal for the host to use - burning things or producing excessive amounts of ionizing radiation might be out of the question, for instance, but inadvertently decreasing blood glucose levels and triggering hypoglycemia due to starvation would be OK.
* The power source would have to fit inside/against the body - something that's heavy/bulky enough to limit mobility wouldn't work.
* The environment (insofar as available resources, atmosphere, etc.) is Earth-like.
* The mammalians in question are intelligent enough to maintain the power source and computer themselves (to a reasonable extent - they're not Leonid Rogozov)
* The computer itself is the only thing that needs power - there won't be any high-draw devices needing power as well, for example.
* The amount of computational power required would eschew using low-power devices like the Raspberry Pi and the CPU type(s) available in most cell-phones.
* The power source would not require direct interaction from the host while in use. (Pedaling a stationary bike would not be feasible, but drawing power through piezoelectric foot implants would.)
* The power source would not necessarily need to be biological/evolutionary in its own right, so long that it is biologically compatible (i.e. titanium implant)
Would it be feasible to power these computers through biological, self-sustaining means? How might this power source affect the host?
Thoughts would be greatly appreciated.
[Answer]
I will investigate electrical energy generation in fishes. This is not the milisecond shocks that electric eels or rays produce, this is the constant electric field generated in most species of [Mormyridae](https://en.wikipedia.org/wiki/Mormyridae) and [Gymnotiformes](https://en.wikipedia.org/wiki/Gymnotiformes). These are called the weakly electric fishes.
The electric fields produces by these fish are constant low level dipole-dipole fields that are used for detection of other creatures and communication. We are not interested in either of those appliations, just the power implications.
According to [this paper](http://jeb.biologists.org/content/216/13/2459#sec-5), *Apteronotus leptorhynchus* (Brown ghost knifefish) generates a 'waveform' electric field that cycles between zero and 10 mV heat-tail dipole-dipole potential. This is effectively a form of AC power generation. Each pulse generates $1\times10^{-13}$ J of dipole energy with frequency of about 1000 Hz. The paper also notes that dipole energy increases as the square of the dipole charge (which is linearly related to potential drop).
Creating a similar continuous waveform field at 400 Hz for a related knifefish *Eigenmannia virescens* takes 2.5 mJ per second. This is only a 5g fish; the difference between the 2.5 mJ of energy spent and the ~0.0001 $\mu$J effective 'power' output is expended by the nervous system. Otherwise, the energy is directly converted from ATP at high efficiency.
Now an electric eel can generate 800V or more by simply taking 6000 or so of the same organ in the knifefish, and stacking them end-on-end to increase electric potential. So we can definitely increase potential output to whatever level we want. We probably don't need 120V Ac, but getting a medium voltage (24 volts maybe?) 60 Hz power source for out computer is totally feasible. It just depends on how much power we want.
So let make a bunch of leaps of faith (called assumptions, if I was actually doing real science). Lets say we can scale up small organs with little loss of efficiency, lets say we can stack them to get the voltage we need, lets say we can continuously operate them at 60 Hz. Lets say that nerve workings cost us 100% of the power output costs: 50 percent efficiency. Finally, lets say that since glucose to ATP is about a 40% efficient process, regular food to ATP is 25% energy efficient. Then lets say we can devote a proportion of our metabolic energy to electricity generation as a knifefish (~25 %).
In that case, we take a 2000 Calorie diet/metabolism, increase that by 25% (2500 calories) and use the difference at 0.25 \* 0.5 = 12.5% efficiency to generate about 60 Calories of electric energy per day. That works out to $2.5\times10^{5}$ J per day or about 3 Watts.
What can you do with 3 Watts? Power a [Rasberry Pi 2 baseline](https://www.pidramble.com/wiki/benchmarks/power-consumption) while under computing load. Not great, but if you make a few assumptions about increasing the power efficiency of computers, you could feasibly get to where you want to go.
So, eat 25% more, add a few thousand electro-organs, and you have your self a bio-computer.
[Answer]
I would look at using TEGs, thermoelectric generators. People produce a lot of waste heat anyway because of the need to maintain body temperature. Cover the body with TEGs and harvest some of that waste heat. The top and back of the head would be a good spot. It's energy people expend if captured or not and doesn't present any extra load on the body.
[Wikipedia link to Thermoelectric Generator](https://en.wikipedia.org/wiki/Thermoelectric_generator)
I was surprised to find this: [Hand Heat Demonstrator](http://www.shop.customthermoelectric.com/TEG-DMO-01-TEG-Hand-Heat-Demonstrator-TEG-DMO-01.htm) and this [Page with demonstration video](http://www.customthermoelectric.com/powergen.html)
The generator is 40mm x 40mm and produces about 40mW. Assuming a useable body surface area of 1 square meter (1.4 for women 1.9 for men) [Body Surface Area](https://en.wikipedia.org/wiki/Body_surface_area) that comes out to (1/(0.04\*0.04))\*0.040 = 25 Watts.
[Answer]
keep in mind computers have shown a steady trend to use less power not more, by creating higher and higher efficiency. but really fats contain the same energy density as gasoline so it's not that unlikely. there is already research along those lines, specifically enzymatic biofuel cell here is a great review of current work for laymen ,<https://www.electrochem.org/dl/interface/sum/sum07/su07_p28_31.pdf>
they even have a cell powering an ipod for a nice visual. One of their goal is small implants to power medical bionics.
Microbial fuel cells work even better and can use a wider range of fuels but the bacteria would not make good implants, engineered human cells might work though.
[Answer]
The human brain draws about 12 to 16 W (depending on source). A human at rest dissipates between 65 and 100 W (depending on source, size and sex). An average resonably-fit human male can produce about 75 W of mechanical power for eight hours ([Wikipedia](https://en.wikipedia.org/wiki/Human_power)), of course with an increase in metabolism and food intake. Thus it is not outlandish to assume that we could generate and dedicate, say, 15 to 20 W for use by our future embedded digital assistant, which should be plenty -- for example, a dual-core Intel [Celeron N300](http://ark.intel.com/products/87259/Intel-Celeron-Processor-N3000-2M-Cache-up-to-2_08-GHz) has TDP of 4 W). The conversion of the energy stored in the form of [ATP](https://en.wikipedia.org/wiki/Adenosine_triphosphate) into 3.3 V DC is left as a simple exercise to the interested bioengineers.
] |
[Question]
[
Several science fiction books picture bigger Terran planets with higher gravity. I'm curious to know what would be the maximum gravity mammals similar to the one on earth could survive. Only bones types and structures that exist in our animal world are allowed, no science fiction or magic (no adamantium bones)
A 10G planet seems tough. Elephants can weight up to 5000kg, but if they were smaller, their bones wouldn't be so tough. Therefore if gravity was 10G, I'm not sure whether a 10 times smaller elephant could still exist. Their bones would be too thin and crack under their own weight.
On the other hand, a 2G planet seems ok. Living there would be like constantly carrying a backpack of your own weight. Some very strong humans could probably survive there. We'd have lots of spinal and circulatory problems but eventually our muscles would grow stronger and we would barely cope with such a world.
What do you think would be the limit?
[Answer]
How much adaptation are you allowing for here? Our existing earth mammals would struggle with increased gravity, and larger ones would struggle more.
If all you are asking about is humans adapting then there is an answer here: [Would the human body support living on planets with a greater gravity than Earth?](https://worldbuilding.stackexchange.com/questions/158/would-the-human-body-support-living-on-planets-with-a-greater-gravity-than-earth)
However in the more general case of life adapting to the conditions I can see life adapting to survive in much greater gravity fields. 10G? No problem. 100G? maybe. What's the limit? We have no idea.
Physical structures would change, bones would be thicker and stronger, creatures would have more legs or at higher gravity levels no legs at all. Mammals shaped like snakes slithering over the surface of a 20G world sounds plausible to me.
Organs would be arranged and function differently, height differences would be minimized (so expect flattened bodies) and nothing would jump or fly. Even small falls are likely to be lethal and climbing extremely hard so most creatures would live on the ground. Burrows and caves would be both dangerous and unlikely so expect small hollows and nests to be the preferred way to live.
[Answer]
It's easy to work out that 3G would impose serious ( long term fatal) blood pressure issues on an un-adapted human. However, giraffes and dinosaurs show that land animals three or more times our height can develop appropriate adaptation, and so human height in 3G is possible with earthly flesh and blood.
10G is more doubtful. There have never been animals standing 20 meters tall on earth. Animals on such a planet would have to be very squat.
One other speculative thought. In high gravity there could be no trees (assuming Earthlike wood).. Without trees there would be no reason to evolve hands for climbing trees. Without hands, is there a path for intelligence to evolve? It's less of a problem if creatures on a high gravity planet are centauroid: four legs for stability plus two (or more) forelimbs for manipulating their environment.
] |
[Question]
[
In a magical world there is a tribe of people divided into termite-like castes. They live in the wilderness, far from most regular humans. They are effectively human; fully conscious and conscientious individuals who are exceptionally loyal to their own kind, not simply because of their isolation from others, nor because of the risk of attack by humans. Their society is split into three castes with specific roles: Queens, Drones, Guards.
Queens are rare, large (2.4m tall), live for centuries, and are almost constantly pregnant, giving birth to all three castes. Drones are common, small (1.2m tall) infertile females. Guards are uncommon, very large (3.6m tall) and strong males.
Let's hand-wave the issue of how Queens are pregnant so often and effortlessly, that's not the issue here. They are pregnant often, with multiple births, and this and labour isn't much of a big deal, allowing them enough energy (just about) to be in a position of leadership. I am interested primarily in the psychology and physiology of the castes, in so far as how it can help explain norms of thinking and behaviour.
Drones and Guards are almost absolutely obedient to the Queens. This is a psychological predisposition which makes their behaviours likely, and is not a physical limit to their ability to harm or rebel from the Queens, which are not by any means capable of fighting. Guards do not abuse their strength to bully the others. Given this context, what psychological characteristics are required for Drones and Guards to be loyal to the Queens, and for the Guards to lack aggression towards Queens and Drones?
I would like answers to discuss psychological functions/dysfunctions in humans in order to understand how these castes would think differently in order to maintain harmony. Physiology is obviously part of this, but I would not like it to be the primary issue outside of how it influences the brain/mind.
[Answer]
## Pheromones
Okay, so this is more of a chemistry-based answer than a psychology-based one, but bear with me here.
Pheromones are excreted by many animals; mostly to attract members of the opposite gender; but can also be used by insects (such as ants, beetles and termites) for other uses such as an alarm system, a food-trail system and even an aggression-modifier system, to name just a few and to tie this in with your question.
**So, how would it work?**
I'm not an expert, so if anyone has more knowledge than me, feel free to correct me here, but you'd have the "Queens" emit this pheromone that both the "Drones" and the "Guards" respond to. Kind of like a drug, these others would be pacified by the "Queens"; the "Drones" so that they are completely subservient to the "Queens" and the "Guards" so they're not aggressive inside our "hive".
The "Queens" could effectively send the guards into enemy lands in a frenzy from the lack of said pheromone (*Drug withdrawal-like symptom?*) effectively making a very powerful army at a whim that would calm down upon returning under the pheromone's effects.
The "Queens" would then have to be protected at all costs and have young; dormant "Queens" ready just in case one would die, so that another can take its place and continue producing the Pheromone
[Answer]
How is this much different from society in the human realm?
Take a feudal/monarchal society:
• A Royalty/Lordship dictate the peasants/serfs ("working class individuals", to be politically correct...) who take refuge beneath their watchful gaze.
• To keep their territory safe (and the serfs in line), the royalty/lordship commission soldiers/knights to protect the borders and the serfs from any threats that may arise - who willingly do war with neighbouring hostiles upon command.
• In return for the knights protective presence, the serfs do day to day laborious tasks for their Rulers, readily placing themselves at their feet in order to remain in their graces.
• Finally, on seeing their peasants stoic faith to them, the Rulers in turn provide them with continued protection by way of the knights, as well as provide them with continued housing and adequate sustainance so they will continue serving the monarchy diligently unto the death.
Without a monarchs "knowledge" or leadership, the system would break down and people would either starve to death or die at the hands of their opposition.
## It is this cycle, this means of survival, that keeps everyone working together.
Queens govern Drones by means of the Guards who willingly work their lives away for the greater good of their "colony". The mind set of your Ter-people will simply need to be one of **dependance, desperation and doltishness**.
The Queen must be seen as the figure of protection/salvation/survival, who without, would mean the sure destruction of the colony. She can influence the people herself by word of mouth, telling them directly: "without me, you're all doomed". Having a majority of mildly simple-minded drones and guards (who believe what the Queen is saying) will ensure her protection and the co-operation of the entire populous.
Having a desperate streak in the drones/guards psychology, by means of fearing death or abandonment, will make them ever the more obedient. *Because if I don't be loyal and behave and serve the Queen, I will be thrown out into the desert to die in agony; or worse yet: the entire colony could suffer for my actions...*
Because really: no-one wants to be that guy who causes the destruction of life as we know it...
[Answer]
1st It won't work if your queen is a mammal, she will never be able bear enough offspring to populate her tribe. Mammal children are few and pregnancies are long.
2nd Social insects cooperate because they're nearly clones of each others, if you "humans" are like ants all male workers should be clones, and all female workers should share 75% of the genes.
3rd Colonies are far from harmonies, even infertile drones secretly lay eggs, and queen not so secretly eats [them](http://www.wildscience.net/wild9_2.asp?num=143&num2=11&st=21&kind=6).
There is no such thing as harmony, in order system to work you have to suppress the selfishness of the genes. In your case speciation might happen with drone & soldier leaving and forming their own nest. If they are intelligent like humans why should they be slaves to the queen.
[Answer]
As far as their psychology I would have the guards love and worship the Queen's the way we do actors and actresses. to be the father of a queen would be considered one of the highest honor. The Opinions of the guards are important because they are essentially the military and the Queen's are always at risk of them usurping the power for themsevles so it's important that the guards constantly be driven to impress them.
Opinions of the workers are less important they could worship the Queen's or they could hate them as long as the guards stay loyal the queens will remain in power. I would recommend if he is serious taboo for a guard to have sex with the work. This would keep the guards loyal to the Queens.
Some of this could also be explained if the queen to make some sort of hormone that keeps the guards loyal and subservient to them.
] |
[Question]
[
Assuming a human had 4 legs and could perfectly use them for walking(they are a bit like centaurs,who have the upper body of a human and the lower body of a horse). Would they have any advantages over normal bipedal humans? What kind of disadvantages would they suffer from?
I would assume that they would be more stable than bipedal humans and that they would be able to move faster than humans. However they would probably be bigger than normal humans due to the 4 legs, bending down to pick up stuff on the floor would be a hell and they probably don't have feet(I can't imagine a four legged creature with feet) and instead have hooves.
[Answer]
Possibly they also might have paws instead of hoofs, but the leg geometry would be much akin to any other quadrupedal animal.
The larger body would also mean, that the base caloric needs of the hexa-limbic being would be much larger: An average soldier is seen as "75 kg" and is assigned 3000 kcal per day to upkeep him under a moderate workload. That makes pretty nicely 40 kcal/kg. A site about horse feeding told me, that just to keep a horse alive, it would need 143 kcal/kg. So, just summing both up and rounding down a bit for you don't need to sustain two brains, I estimate something in the area of 180 kcal/kg is the need to sustain these beings under some light to moderate workload. Which is about 4.5 times what a human needs per weight, and these beings are much heavier in addition? Taking something like a middle grounds, 160 kcal/kg sounds like a reasonable number too.
The additional space in the 'lower torso' between the middle and hind legs, however, it could mean that the whole 'upper torso' between the front limbs and the middle limbs could be devoted to having incredibly large lungs while the lower torso contains the digestive system, heart and blood cleaning systems.
Because these hexa-limbic beings would have entirely different needs, housing would look unfamiliar to quadro-limbic humans: chairs are more akin to a bench on which one rests the belly (instead of sitting on them), Beds might be unheard of (or more akin to the chairs), pillows would be in high demand.
Another of the needs the hexa-limbic beings would likely have is space: A human with 4 limbs can operate in any place comfortably, that offers space in the shape of a tube of 1 meter diameter and 2 meters height, give or take some for the size of the human. The Hexa-limbic beings would occupy most likely a box with a 2 by 1 meters floor and 2 meters height - which would seriously impact the design of cities and how some industries have to be handled.
Possibly the hexa-limbic beings can't manipulate things close to the floor very well for they can't bend down that much easily and crouching is not possible at all. So to operate things on the floor or pick them up, they most likely have to lay down - or they need to have longer arms, that almost reach to the ground.
Procreation of said beings might be a bit complicated: most quadruped animals have positions in which they go for this that would be pretty much hindered by a second torso sticking out orthogonal from where their shoulders are.
[Answer]
There's a possibility that your four legged humans would be shorter, more of a pancake shape so that their center of gravity would remain stable even at high speeds.
And if we are talking about different kinds of feet(or foot), hooves would definitely allow the human to move faster across open plains, insect like feet could conceivably allow the person to climb up walls(I think you would need a lot of feet to allow that though), paws would give the humans a natural weapon.
A human with four legs would definitely be more mobile than normal humans, they would also need their lower body to be larger to accommodate the increased size of the organs. Which is answered well by trish
] |
[Question]
[
What many people mayn't know is that there actually three basic types of algae:
[](https://i.stack.imgur.com/t53I5.jpg)
Green algae, the origin of the kingdom Plantae
[](https://i.stack.imgur.com/zXWdi.jpg)
Brown algae, found primarily in kelp forests
[](https://i.stack.imgur.com/v6VXr.gif)
And red algae
For this question, let's disregard brown algae because brown algae is a geologic newcomer--no older than 150 million years.
In this alternate scenario, plants evolved from both green AND red algae. Plants descended from green algae are photosynthetic and can be found in every single terrestrial habitat, even deserts. They come in the form of ferns, mosses, grasses, flowers and trees. Would plants descended from red algae behave in the same way, or would they have different environmental requirements from plants descended from green algae?
[Answer]
**They'd likely all evolve to be green.**
Plants aren't just green because their ancestors are green. Plants are green because, in most environments, being green is more advantageous than being red.
The leaves of green plants tend to be dominated by chlorophyll, while those of red or purple plants have a different pigment called [anthocyanin.](https://en.wikipedia.org/wiki/Anthocyanin) Plants have evolved to produce both of these pigments, and generally whichever pigment is more beneficial for survival in a given environment is the one found in plants in that environment.
If there existed plants that ancestrally used a red pigment, like anthocyanin, it's likely that they, too, would evolve the ability to produce a variety of different pigments, some of which would be more useful than others in some environments. Most plants would probably be green, regardless of their ancestry, because chlorophyll is more efficient at converting light into energy, in most environments.
If, unlike plants, our new red organisms couldn't produce photosynthesis, they'd probably die out. Chlorophyll-based plant life is dominant on earth because it's the most efficient, and non-chlorophyll based life would likely be unable to compete with it in most ecological niches.
Interestingly, there's a hypothesis that green plant life wasn't always dominant on Earth. The [Purple Earth Hypothesis](http://www.livescience.com/1398-early-earth-purple-study-suggests.html) states that retinal-based photosynthesis evolved first, but that retinal-based organisms were unable to compete with plants in most ecological niches. They still exist, though not in great numbers, with [haloarchaea](https://en.wikipedia.org/wiki/Haloarchaea) being the prime examples.
[Answer]
The red and green algae's, all land plants and glaucophytes are archaeplastida. Plants aren't "more evolved" versions of algae. They're all cousins in a not-yet fully understood family tree.
They all evolved separately from common ancestor species.
The red algae are only red because they have adopted to the unique resource niche of light and carbon sources underwater.
They would have no reason to exist anywhere else.
[Answer]
Copper beech trees [are mutants with red-purple leaves](http://www.woodlandtrust.org.uk/visiting-woods/trees-woods-and-wildlife/british-trees/common-non-native-trees/copper-beech/), though this [Kew Gardens information](http://www.kew.org/science-conservation/plants-fungi/fagus-sylvatica-copper-beech) says their leaves turn 'spinach green' at certain times of year. Also many rainforest plants have [red or pink leaves](http://rainforest-australia.com/Tropical_Rainforest-Specific_Adaptions.htm) when the leaves are young. The red chemicals are possibly to protect them from the sun or from leaf-eating creatures.
So red plants are entirely possible.
[Answer]
Let's stick with a yellow sun in order to explore a possibility...
Since red plants will be less efficient at collecting sunlight than green plants, what if there is another source of energy on your planet other than sunlight that they collect? Some kind of ambient radiation coming from a mineral or process under the surface perhaps? Maybe the red plants are adapted for converting hard radiation into energy?
You could even use a cluster of red plants as a guide to avoid a certain spot on the surface perhaps.
If they are efficient enough at collecting radiation, what if some types could actually grow in a cave with minimal or even no sunlight at all? Underground foliage?
Could make for some cool looking "alien planet" concepts.
Edit: removed red sun option.
] |
[Question]
[
**Is it possible for a planet and moon to generate electricity in some way?** Could a combination of magnetic fields and iron content in the crust or core produce electromagnetic induction due to the rotation of either planet or moon, and also the orbit of the moon? Here are a few ideas:
The moon orbits over both poles of the planet, causing an alternating field to pass through it.
The magnetic field of the planet is perpendicular to its axis of rotation, and the moon orbits around its rotational equator in the opposite direction of the spin. This would cause an alternating field through the moon.
The moon orbits like our moon, where it is always facing towards the planet. One of the moon's magnetic poles is pointing towards the planet. As it orbits, the planet experiences an alternating field.
**Are any of the above plausible? If so, would they actually generate a voltage in the core of either planet or moon? Are there any other possibilities?**
[Answer]
There are *other* possibilities:
**The magnificent [Jupiter-Io Flux Tube](https://ase.tufts.edu/cosmos/view_picture.asp?id=1174)**
Now you gotta consider that you probably cannot live on the planet itself in this case1, but beside that there's a huge potential energy.
*Briefly:* Due to the nature of [Jupiter and IO](https://en.wikipedia.org/wiki/Io_(moon)#Interaction_with_Jupiter.27s_magnetosphere) a so called [flux tube](https://en.wikipedia.org/wiki/Flux_tube) exists between them through which huge amounts of electricity are discharged into jupiter's atmosphere which there eventually end up as lightning.
Harnessing power from this phenomena has been used in scifi for some time, alas at this moment I couldn't find a single passage about it..
1Alas considering that you'd need the technology to harness this power, you'd likely also have the technology to colonize such planets/moons
[Answer]
Under your heading of "other possibilities"
**Tap the gravitational effect of the movement of the moon relative to the planet.**
People have been using this method for centuries, from [tide mills](http://woodbridgetidemill.org.uk/) to modern [hydro-power](https://en.wikipedia.org/wiki/Tidal_power).
While this is less flashy than what you had in mind, it's very simple and reliable.
[Answer]
There is something called an "electrodynamic tether" in the aerospace industry, which almost matches your description. If a moon were low enough to interact with ionospheric plasma and had electrically conductive regions exposed (a metallic core, brines, etc.), it could drive enormous currents at the cost of lowering the moon's orbit. The circuit passes through the body and is completed by the plasma.
The only situation in which I could imagine this happening is with a metallic moon (perhaps a captured metallic asteroid) the orbit of which has only just gotten low enough for the effect to be significant. If the current runs continuously, the orbit will decay very rapidly. The moon can not be large. It must be small enough to be held together by electrostatic forces; if it were held together by gravity so far below the Roche limit it would be torn apart.
It would also be possible to drive moon outwards by actively supplying correspondingly huge currents.
You can read more about electrodynamic tethers on Wikipedia (<https://en.wikipedia.org/wiki/Electrodynamic_tether>) or in "Space Mission Engineering: The New SMAD", pp. 782-783. (Edited by James Wertz, David Everett & Jeffery Puschell.) It is not mature technology.
] |
[Question]
[
Suppose in the far future, after humanity has acquired FTL travel and communication (and other assorted technologies) from more advanced alien species in the universe, a small portion of a specific community of humans decides they want to abandon an absolute dependence on the technology of the time and return to a simpler, more human-centric society. They scan the heavens looking for a suitable planet and eventually [find one](https://worldbuilding.stackexchange.com/q/33603/6986) in an uninhabited part of the universe.
They trek across space and arrive at the planet ready to colonize it. As they settle into their new home, they notice that the [native fauna](https://worldbuilding.stackexchange.com/q/33040/6986) are capable of seemingly supernatural abilities. After a few years and some research, the settlers discover that a [special device](https://worldbuilding.stackexchange.com/q/47251/6986) can be used to contain and control the native fauna.
With proper training, the controlled fauna can be used to produce immense quantities of energy and material goods, as well as make the acquisition of existing goods effectively trivial, once again providing the human settlers with a post-scarcity society.
However, the special device is not easy to make; it requires a high level of technical know-how and a considerable investment in resource acquisition and production capability, all of which is hampered by the wild native fauna. A few dedicated, determined individuals with the right smarts can each produce one or two of these a week by hand, but this cannot support the colonists' needs/desires.
*What would be the most believable/reasonable economic structure for a post-scarcity society dependent on a scarce resource?*
## The Colony
The colonists have an interest in building a society no more advanced than a little further along than the most technologically advanced cultures on Earth today. There are three general culture interests: basic needs, high technology, and the middle ground.
**Basic Needs**
These colonists form small, tight-knit communities of up to a few hundred people. Everyone knows everyone due to social gatherings and open exchange of goods and services. Locally, they are willing to lend a hand for a meal or camaraderie. However, they do trade with other cultures and require some form of exchangeable good or service to meet that need.
**High Technology**
These colonists like things to be done for them, so they are free to spend their time however they choose, whether it be rock climbing, cross-country racing, writing, painting, etc. Communities here form in the mid to upper thousands, and individuals may not know their neighbors if they met them at a social gathering. Robots and tamed fauna provide goods and services to meet the needs and desires of the colonists, so they provide goods and services to other communities as they choose.
**Middle Ground**
These colonists prefer to do important tasks on their own, while robots tend to the minutiae of daily life (e.g., garbage collection). Individuals have the luxury to spend their time however they choose, but must weigh their choice with the day-to-day needs of survival. Tamed fauna are an asset in protecting against wild fauna, so a steady supply of the containment device is essential.
**General Information**
There are few than a hundred thousand humans on the planet at this point. Settlements may be spread far apart with the only reasonable means of transportation by technology or well-trained fauna. Contact with the rest of the universe is one-way; no ships or communication can leave the planet without being intercepted and the colony destroyed (the planet isn't supposed to be settled). The communities have no reason to quarrel and only a select few people off-world even know the planet and its colony exist, so no piracy. The capacity to control a wide array of the native fauna will mean all societal/cultural needs can eventually be met.
[Answer]
A society in which everything is easily available behind the bottleneck. Almost post scarcity but not quite.
The entire economy of the planet is based around the skills of one specific group of people and their rate of production. Therefore also how many people they train up with the skills to create the special device. Greater numbers in training will reduce the immediate rate of production in favour of a higher future rate of production and improved future economy, but I'm assuming there's a base rate you can't risk falling below, so you can't all out stop production in favour of training.
## The Government
The people who control the bottleneck control society, you're going to end up with either a technocracy directly controlled by these people, an oligarchy because they're the gateway to wealth or communism with the constructors being the first among equals. (All animals are equal but some are more equal than others)
Ultimately all these come to the same thing, the power will be held by those who control the bottleneck. The difference is in what they choose to do with it. Even in the best of all possible worlds, they're unlikely to happily sit there being the only people on the planet who do any work without a significant increase in status.
## The Economy
The economy is a mess, there's only one item that has any value and that has all the value. It's apparently critical to continued life on the planet and it's a consumable of highly limited supply. It's a basket case economy. Totally unable to operate in anything resembling a normal manner.
## The Currency
The currency is either worthless or backed by poké balls, it's the only thing that has a non-imaginary value. Post scarcity makes a mockery of capitalism which is driven by the balance of supply and demand. There's a single item in limited supply and everything else is dependent on that one item. Either that's your currency or that's the basis of your currency.
## Ways to recover the economy
**Capitalist option:** Industrialise the process. Set up supply chains for the parts and materials required. Allow some of the value of the devices to be spread among more people on the supply chain. Eventually this is likely to lead to higher production rates and a reduction in the bottleneck reducing the value of the devices and the relative power of the people who can build them.
**Socialist option:** Communitise\* the process. Each village has a master constructor and apprentices. A few times a year the whole village turns out to gather the materials required, journeyman constructors come in from the surrounding area to help with the construction. It's an all in process controlled by your master craftsman but everyone in the village has an investment in it and everyone benefits.
\*It's a word because I say it is, that's how you get new words.
[Answer]
>
> What would be the most believable/reasonable economic structure for a post-scarcity society dependent on a scarce resource?
>
>
>
This is not a post-scarcity society. If your producers can't produce the special device, then those are scarce. The economy will either center around them or ignore them.
There are essentially three paths that an individual can take:
1. Builder. These are the people who actually construct the special devices.
2. Military. These are the people who manage and protect the special devices.
3. Outside. These are people who reject military control and automated products.
### Builders
Since building a single special device makes someone incredibly rich, they won't work a lot. Instead, they'll build a few special devices over the course of a lifetime. One to live off. They'll trade special devices for the few things they can't build, e.g. military protection. A special device also makes a great dowry for a child looking to marry.
They may also have to give training as part of their deal for protection. Perhaps an apprentice every ten years. Perhaps the apprentices do most of the actual work of building a special device.
### Military
I would expect a feudal structure to be most common. Essentially we have a special device owned by a noble and surrounded by military. Members of military families are full citizens--that's how they convince people to join.
It would be possible to have a more democratic structure, but it's going to still have to be highly military. Perhaps mandatory service is the price of citizenship. Draft dodgers lose special device access.
A weak military will lead to outsiders taking the special device away. This is why I think that a feudal system develops. The original system will be more democratic, but over time democracies make bad decisions and get replaced by either internal coups or external conquest.
### Outsiders
Since the special devices are scarce, not everyone will have access. These people will have a more traditional economy. Some, perhaps most, will be farmers. The special device people may have charities to help support this. Perhaps free tractors or something.
The more attractive outsiders may marry into insider families.
The more martial outsiders may join the militaries of existing special devices. Or join gangs outside.
Some areas will reject the special devices, refusing to use their products. They are likely to be most aggressive about doing their own manufacturing.
[Answer]
Here's a few thoughts from the Orion's Arm Universe Project:
**Non-fungible Goods and Services in Post-scarcity Societies**
<http://orionsarm.com/eg-article/5383577a65d8a>
Technically speaking no post-scarcity economy has truly eliminated scarcity (rather the term comes from the transition to economics of abundance). Correspondingly there will always be certain commodities that are scarce, even if copies can be mass produced. Examples of these non-fungible goods and services are original pieces of artwork, specific areas of land and services from a particular individual or group. Scarcity economic principles still apply but generally the demand for non-fungible commodities is still so low that most individuals are excluded from the economy. Systems of dealing with this (outside of individual gifting) differ but most systems account for this in some way. Below are a few common methods.
**Private Markets**
As with scarcity economics private markets can be used to trade unique items or services. Currency can be fiat or not (depending on local custom). Most sophonts rarely have a need to interact in a private market as social infrastructure can provide for nearly all needs, exceptions include specific living space, art, branded goods and live entertainment. It is often difficult for sophonts to enter a market if they do not already own something unique or are capable of a desirable service. There are various solutions to this varying by local custom, two prominent examples are to seek a private loan or to make use of publicly available education and augmentation to create something able to be sold on a market. A third and common option is rapid barter (see below).
Common Ownership and Rentism
Various goods such as original artworks or plots of land maybe held in common ownership. As such it is not possible for them to be traded between individuals (at least without true ownership still residing with society at large). Because of this it is quite common for a form of rent to be employed with individuals paying with whatever resources their economic system allows (e.g. a portion of their socially provided allocation of credits). Rent may be conditional with set durations which are determined legally but could also depend on how much a sophont is willing or able to pay. Alternatively or additionally an individual may have to meet certain criteria before they are eligible to rent.
Common Ownership and Lottery
Non-fungible goods are held in common ownership but they can be allocated to individuals for a set time in a lottery system. Usually sophonts put their name in for a specific commodity and a periodic lottery determines who gets it as well as what conditions come with the allocation. Once the time is up the sophont loses ownership rights and has to apply again.
Post-scarcity Economies: Characteristics and Considerations
<http://orionsarm.com/eg-article/53727c57a8402>
**Autonomous Industry**
Almost all post-scarcity economies arise after significant development in automation, both physical and intellectual, that almost entirely negates the need for sophont labour. In effect automated technologies (chiefly robotics and artificial intelligence) reach a point in which all tasks including the design, construction and installation of new automation are automated. This feature of post-scarcity economies is the basis for most other characteristics and is the spur for the development of post-labour economic theories.
**Steady state and Circular Economics**
With sufficient economic commitment and/or molecular nanotechnology industries can be designed with near-perfect recycling in mind, facilitating a transition towards a steady state economy. Waste products can either come in forms safe to release into a surrounding biosphere or be used as raw materials for other industries. Particularly with advanced nanotechnology any substance can be broken down into its constituent elements (given energy and time) ready to be rebuilt. Whilst not a necessary characteristic of post-scarcity economies most adopt the practice as it avoids the huge potential for environmental damage unchecked growth of automated industry could cause. Whilst the resources available to a post-scarcity economy can be vast (potentially multiple solar systems worth of matter and energy) autonomous industry can potentially grow exponentially. This has been the cause of more than one Cinder system. In addition steady state economic principles are often put in place to prevent overconsumption or greed and to encourage an ecologically friendly culture.
[Answer]
### Basic considerations
First of all, we have to see that this is an isolated system. For the economy, this is very important.
Thanks to the device, the society comes to post-scarcity, meaning that all goods are available in quantity for little to no cost. This means that the production on the *device* is complex, and lengthy, but not expensive per sae.
Due to the fact that your colonists establish themselves in communities, as possibly as a consequence of the first phase of the colony, a currency system was established. The services of one community is paid for using the currency system. And non-basic goods also need to be paid for.
### To each culture, their economy
The society rely heavily on robots to produce the *device* but also to produce raw materials, or transform them. The Hich-Tech people focuses on that essential part of the economy. They are responsible for the production, maintenance and development of the robots and automatic systems. And they sell those to the other cultures. They really love the tech, so they tend to see it more like hobbies than the others. And from that they get a source of revenues.
People have a lot of free time. But too much free time could be boring. What do you do the whole day? People tend to turn to various forms of entertainment and Art. And none does it better than the group of basic needs. Their open communities favour the exchange of ideas and great creativity. Their pure approach of the Universe shows in their production, and are very appreciated.
The middle ground, as their name indicates, provide the rest. They held the finance (banks, etc.). And deal with one of the main task of the world: the fauna. They are the most familiar with the fauna. Seeing which beasts can be tamed, etc. They provide the other cultures with tamed beasts, which can be herded in automatic farms. They provide financial investments for new tech and/or Art, distribute the goods, etc.
So all the goods still have a cost, But that one is very low compared with the services described previously. So no-one really miss any essential good.
### The *device*
That is the most complex element. The whole society, economy and lives depends on it. It is essential to produce as many of them as possible. The few brilliant mind capable of producing it are fully dedicated to the task. In that they are strongly supported by the techies to provide robots and production lines, and the middle ground for their specific knowledge of the environment.
A very important part of the economy is turned towards that. Companies are built around the few people able to do it. And the competition is pretty hard. Due to previous cases, the security around those people is also very important. For those companies, losing one of their producer would be disastrous. And due to the necessities of wandering the nature, encounters with wild animals is quite frequent. Work accidents have to be avoided at all costs. But most importantly, one has to make sure that no company would decide to get a competitive advantage.
Apart from that, I would expect people to spend time trying to optimise the process, to teach others, and possibly see how to perfect, automatise the production process of the *device*. So a lot of research and development would be involved, making the tech culture very important.
### Foreseen crash
At some point, the *device* will lose its limiting factor. Either there will be many of them, or they managed to produce it in a cheaper/faster/easier way. In both cases, the main component of the economy will crash. How things will be dealt with then, could fill a whole book.
[Answer]
A more serious take is given by McCarthy’s *Queendom of Sol* series. The society is dependant on nanoscale *fax* technology and is has replaced everything else for all purposes. But a fax plate can’t make a fax plate. The colony slowly fails as they can't maintain or produce enough fax plates. It declines from post-scarsity in stages to the ruling class having extreme opulence and the masses living in poverty.
[Answer]
A council of elders is appointed to balance inequities. The planet's inhabitants take grievances before the counsel, whose erudite members, assisted by state-of-the-art modelling software, address each scenario and take whatever measures are deemed necessary to resolve the perceived inequity. All inhabitants agree to live with the council's decisions and to contribute collectively whatever resources are required to re-equilibriate whatever inequities or injustices arise. Council members are beyond corruption because corruption is punishable by immediate expulsion from the planet.
] |
[Question]
[
The habitat of the creature in question is most commonly atop mountains (or in moist areas). Such an idea would mean that the creature wouldn't need a heart or stomach to break down things into blood. It would most likely become sick easily, as the water it drinks could be disease ridden. The wings, legs and especially brain contain small amounts of liver-like tissue that extract oxygen from the water and uses it in much the same way as our bodys.
Is this possible?
*Note-
I'm new to this question-answer site, so what I'm saying might be absolutely ridiculous, let me know if I'm way off.*
[Answer]
Yes...and no.
We already use water for blood, we just float things around in it - mostly blood cells but things like platelets etc as well.
In order to be used to carry things around the body of the insect then you need to float things in the water, and then eventually you can't really call it water any more.
So yes you could certainly have a much more dilute liquid, however consider things such as what would heal a cut and prevent all the water squirting out? How would the water carry things like oxygen etc which the insect needs to survive?
See this article for another important point:
<http://archive.boston.com/news/globe/health_science/articles/2005/10/17/do_insects_have_blood/>
>
> Insects do have blood -- sort of. It's usually called hemolymph (or haemolymph) and is sharply distinguished from human blood and the blood of most animals that you would be likely to have seen by an absence of red blood cells. In a sense, as you might guess from the name, hemolymph plays a sort of double role, doing the jobs that both blood and the lymphatic system do in humans and other vertebrates.
>
>
> Hemolymph is mostly water, plus various other odds and ends like amino acids, ions, lipids (fats), carbohydrates, etc., as well as some pigments, but these are rarely very strongly colored. Typical colors for hemolymph itself are greenish or yellowish. There are also some cells, called hemocytes, that float around in the hemolymph, but they are part of an insect's immune system.
>
>
>
So standard insects already use something different from what we would call "blood", but again it's stuff being carried along by water. Their blood though does not carry Oxygen:
>
> In insects, most of the organs that need oxygen are pretty near the air, and ''breathing" is done by taking in oxygen through lots of little openings to the outside. The oxygen gets to where it's needed mainly by diffusion.
>
>
>
This is actually one of the things limiting the size of insects. They have no way to get oxygen to things deep inside their body.
[Answer]
*Note: this answer assumes your intention isn't to have a normal circulatory system (only with water instead of blood) but rather that the insect takes in water, pumps it through the body, extracts nutrients and oxygen from it on the way and excretes it after one pass.*
If your creature ingests water that provides oxygen and/or nutrients to its body, its mouth essentially takes over the function of the heart, so it would still have a heart.
It would also be limited to whatever nutrients can be absorbed directly, without any processing. That's a very risky situation (a dose of rainwater might cause the creature to starve) and likely to put it so far behind the competition it wouldn't last long if there are any other lifeforms in the area.
Blood is a fine-tuned distribution and maintenance system that provides many benefits aside from transporting nutrients. If blood varied in oxygen, mineral and nutrient content like the average water in the environment, our human brains would have never had a chance to evolve.
Likewise, the digestive system allows creatures to process wildly different food sources, whether they are big and tough (teeth and stomach acid), infected (stomach acid again), have their nutrients locked away (intestinal bacteria) or simply lack some vital nutrients (hey, bacteria again).
As mentioned before, by skipping on the extras, your creature pretty much needs to find the exact nutrients it needs floating in the water. So forget pure and idyllic mountains, think smelly sewage outflow of some really health-conscious humans.
[Answer]
[Sponges](https://en.wikipedia.org/wiki/Sponge) actually do something like this. They have no enclosed circulatory or digestive systems, instead they directly expose every cell to the surrounding medium thanks to their poriferous body structure, filtering oxygen and nutrients directly out of the water.
However, this mechanism is far too inefficient to sustain the higher energy needs of a mobile animal. Also, sponges live underwater; to repeat this with a land-dweller you'd need the creature to basically be drinking constantly in order to supply itself with dissolved oxygen.
] |
[Question]
[
### Summary version:
So we're talking people living on top of 30 miles of topsoil, fake dino fossils and water on the **outer** surface on a hollow (but sturdy) [unobtanium sphere](https://worldbuilding.stackexchange.com/questions/37833/how-large-would-a-world-have-to-be-for-a-sailing-ship-to-never-make-it-past-the) with a radius about 1 AU. The sphere has an intermediate sized singularity at the core providing gravity of $1~g$ at sphere surface.
**How can I provide sufficient lighting? I am not fussy about things like day length, I just want some light both equatorial and in my polar regions. How do I get it, without further liberal use of unobtanium?**
---
### Full Description
So I've been toying with the idea of a large Niven-like world. I don't like rings however. So instead, in an act of cosmic vandalism, I've handwaved in a hollow unobtanium sphere, using its frankly unbelievable compressive strength to effortlessly resist collapsing under $1~g$ of acceleration from a bikini-clad singularity at the center of the sphere, massing a moderate $1665~M\_{☉}$ (solar masses). To make it more fun, my land, seas, tectonic simulators, dinosaur bone planters and other such-stuff is on the outside of the sphere.
This spares them from withering under the gaze of the bikini-singularity (for it is written that none shall see a near-naked singularity and live).
However, it does bring up the rather annoying question of providing adequate lighting for my inhabitants. First, however, a bit about the sizes we're talking about.
Let there be:
$$g=G\frac{M}{r^{2}}$$
where
$g$ - local ("surface") gravitational field
$G$ - gravitational constant
$M$ - mass of another body
$r$ - distance from another body
$G=6.67428 \cdot 10^{-11}~\text{N}\left(\frac{\text{m}}{\text{kg}}\right)^{2}$
$M = 1,665~M\_{☉}=3.33 \cdot 10^{33}~\text{kg}$ - our constructors like the number 3.
Solving for $g = 9.8~\frac{\text{m}}{\text{s}^{2}}$
We get $r=1.50 \cdot 10^{11}~\text{m}$, which suspiciously conveniently is right about 1 astronomical unit (i.e Sun-Earth distance).
**So we're talking people living on top of 30 miles of topsoil, fake dino fossils and water on the outer surface on a hollow unobtanium sphere with a radius about 1 AU.**
Now, I'm ok with the polar regions being a bit dark, but I don't want them in eternal darkness either, as it tends to do nasty things to my sphere's vapor circulation (think 60 mile glaciers). To provide lighting, I'll have a series of planets (I'm thinking somewhere in the range of Jupiter to Brown dwarf in size), which contain sufficient artificial fusion burners to provide day-like illumination.
I was thinking about having them in a nice Klemperer rosette (circling about sharing an orbit, with my burners causing occasional flaring to maintain orbits) like thus (not to scale, obviously):
[](https://i.stack.imgur.com/NgAU7.png)
But assuming they're on the black-hole equatorial plane, this leaves my polar regions depressingly dark.
**How can I provide sufficient lighting? I am not fussy about things like day length, I just want some light in my polar regions. How do I get it, without further liberal use of unobtanium?**
[Answer]
Why are you bothering with Jovian planets with fusion reactors? Your world is 1,600 solar masses, you can have some genuine stars orbiting it.
I would use some big, bright stars placed fairly far out so the heating was as averaged as possible--the problem is not merely to provide some light, but to provide some moderation to the weather. A single sun-sized polar-orbiting sun-sized star would provide Earth-normal light when overhead and eventually cover every spot assuming the super-planet is rotating but it would take 25 days/orbit and many orbits to cover the whole thing. A ring of stars would help but if you want a stable orbit you can't really go using multiple rings.
I suspect you want something like a 60 degree inclination.
[Answer]
The answer is quite simple. Move the plane of the light producing bodies *off* the black hole equatorial plane. Frame dragging from the black hole will cause the shell-world to rotate in its equatorial plane, and the polar regions will rotate in and out of direct light, much like the poles of earth. This does cause another problem though. Having the light producing bodies orbit a Kerr black hole off the equatorial plane will destabilize the orbit you suggest, but this will work in the short term (and short term astronomically can mean millions of years), and it may be a more desirable problem to have (I couldn't say because I'm not sure what the limits you are wanting to place on your omnipotence here).
] |
[Question]
[
I'm writing a story set in the early Lower Paleolithic era, in the area around where Ethiopia currently is.
What kind of names would my characters have? Do we have any knowledge of how people were named back then?
I understand it's almost certainly impossible to have actual records of what people were called, but even knowing what sounds were in use in that area and time period would be useful.
I'm looking for actual names, as in the phonetic sounds they would have been made of, but potential meaning behind them is also useful information.
[Answer]
Well, look at it another way: How would I name my own kids, or how would I decide on a nickname for my friends?
One (denoted as *A*) tends to name a person (denoted as *B*) based on the qualities A wants to see in B, or based on qualities already observed. We also often name B after other people/entities (denoted as *C*) that already exist, because we like C and wants B to be just like C. There's also people who name B as A Jr. Nicknames can also be based on something he has done.
If you are writing about a hypothetical civilisation, then you should look at names of Ethiopian society at a matching level of civilisation, though you should be aware of how much influence the outside world has on Ethiopia. Find a moment in the history of Ethiopia that matches your civilisation's technological, societal, religious and geopolitical situation best and see what names are in use.
If you are writing stories about the Homo Erectus who live in that age, however, I have a few (crude) suggestions based on the scenarios I listed. Note that there's still a long way to go before complex language evolves.
* Naming after desired qualities: Hunter-gathering is in full swing during the Lower Paleolithic. Males would likely be named after desired qualities of hunters (eg. Courage, Strong Arm) while females would likely be named after the desired qualities of domestic life (eg. Sandwich, Man Friend)
* Observed qualities: People are also frequently named after what is already seen in them, especially what they resemble as a baby (eg. Warthog, Sunflower)
* Naming after existing people/entities: There's not much in the way of religion or recorded history, so at most you'll just be naming people after other people you personally know. Of course, they can be named after non-human stuff that they like (eg. Rainbow, Giraffe, Sabertooth)
* Naming after what they have done: examples can include, for example, Shadowstalker, Tuskbreaker, Toemender...
Ok, so maybe some of those names sound weird, but it's an idea, right? Also, you can look at examples from existing hunter-gathering societies that survived into recorded history. For example, among the Iroquois, newborns are given a baby name, which are held until the rite of passage where they formally take up an adult name. In such cases, baby names are usually named after desired or observed qualities, while adult names are based on some achievement in pre-adult life or events during the trial. Also, chieftains may hold a spiritual name that is used in place of their adult names only for the duration of office, resuming the adult name after relinquishing the position. Such names could be based on rare phenomena in the natural world that prehistoric humans would attribute to the supernatural (eg. Five Moons, Fire Lake, Blue Flames, White Saber, Black Sun etc.)
[Answer]
I recall when the movie adaptation for [Clan of the Cave Bear](https://en.wikipedia.org/wiki/The_Clan_of_the_Cave_Bear) came out, there was some hype on the "authentic" language reconstruction.
There have also been articles in Scientific American about the roots of existing languages.
So yes, other writers have done exactly that. You might look at such examples and see what *they* used, or follow any author's notes concerning how they made that determination.
] |
[Question]
[
I'll try to keep this question as concise as I can, but I'm not great with technical jargon, so a simplified answer would be greatly appreciated.
Here's the set up:
I have binary star system with two yellow stars of equal mass orbiting each other. Around those stars are multiple planets, two of which are inhabited and share the same highly elliptical orbit (I'm imagining a football shape with the stars in the middle), but on exact opposite sides. One of these planets (A) is similar in axis tilt to earth, so I'm assigning it a similar seasonal progression (taking into account how the change in orbit will affect that), but the other planet (B) has an axis with more angle (something like 27 degrees, rather than Earth's 23) and their Milankovitch Cycle is considerably shorter as well (10,000 years, compared to Earth's 26,000), which I understand might impact the length and severity of its seasons.
Clarification: I'm using the word seasons not to describe the weather of an area, but more the amount of direct sunlight/warmth a part of the planet receives. For example, Winter Equinox in the Southern Hemisphere on Earth is when the South Pole receives the least amount of warmth/sunlight, which corresponds to the Summer Equinox in the Northern Hemisphere, where the North Pole receives the most amount of warmth/sunlight.
My research has lead me to believe that planet A will have a seasonal progression for each hemisphere more or less like the following:
* Winter 1 = Long and harsh
* Spring = Shorter than winter, very warm
* Winter 2 = Long and gentle
* Autumn = Shorter than winter, less warmth than spring
And the seasons would just repeat from there.
What would planet B's seasonal progression look like compared to this?
[Answer]
The climate and seasons will depend on:
## Dual-Star
A stable orbit implies no significant perturbation when getting closer from one star. It implies that the planets are far enough from both stars, which will appear very close from each other in their sky. As a consequence, the climate will not be impacted by the dual-star configuration: it will behave like a one-star system.
## Eccentricity
The earth solar irradiance fluctuates by about 6.9% yearly for an eccentricity of about 0.0167 (nearly circular). The orbit you describe is completely different, with a distance to star(s) likely to double. In this case, minimal irradiance will be 25% of the maximal irradiance.
## Axial tilt
Considering your orbit description, the effects of the tilt may fall short compared to the eccentricity impact : the tilt does not affect the total energy received, only it's local (planetary) distribution.
## Conclusion
The orbit you describe1 will lead to huge irradiance amplitude due to orbital eccentricity. This will lead to extreme seasons, unless the planet can store energy and amortize the cycle somehow (like oceans storing energy on earth, but you'll need that on another scale ; or a full greenhouse venus-like system).
1 which is probably unstable : two planets orbiting on each other's L3 point is not a stable configuration.
[Answer]
They're Milankovitch *Cycles* there are four of them that combine to effect the long-term climate of Earth you won't get that much change just by altering only one of them. The seasons themselves can't be affected on a year-by-year basis by cycles that are short term only on a geologic timescale. Planet A isn't going to have anything in common with the Earth in a highly eccentric orbit, it really isn't going to be anything like Earth if it's in a binary system, in fact it's going to have to be so far from those stars it'll freeze solid. That's not a possible star system anyway, the stars can orbit a mutual centre of gravity or one can orbit the other, they cannot "orbit each other".
The 27 degree tilt *is* going to create more extreme seasonal variance, summer will be hotter, winter colder, spring and autumn shorter, from memory the difference is about twice the change in tilt, as a percentage, roughly. If you put the two worlds next to each other and looked at them on extreme timelapse, assuming that Obliquity (change in axial tilt) is the only cycle that has a relative difference, you will see a rather different rhythm to the advance and retreat of continental ice sheets what the difference will be is anyone's guess given how little we really understand climate.
For the sake of interest the Milankovitch Cycles are Obliquity, the variation in degree of axial tilt, Eccentricity, the degree to which the orbit deviates from circular, Longitude of Perihelion, where in the cycle of seasons our closest approach to the sun falls, and Axial Procession, where in our orbit compared to Perihelion the summer and winter actually falls, due to the "direction" the rotational axis is pointing. These cycles combine to give Earth an ice-age periodicity of about 100,000 years due to the constructive and destructive interference of the variations in [insolation](https://en.wikipedia.org/wiki/Solar_irradiance) and insolation distribution that the cycles each create. This is also effected by land distribution to some degree as land bound ice is very important to net insolation uptake on a planet.
[Answer]
I would think an M class planet in the habitable zone of its solar system, with a wobbly axis as it spins would do one of two things.
1.
It would increase the speed at which the seasons change, so you would go from spring to summer, in one day, then autumn to winter in one night, and so on.
2.
It would double the number of seasons the planet experiences.
] |
[Question]
[
In this world, human are able to dive into story (books, movies, game) at will and able “log out” whenever they want. Once they are in, they will be subjected to the rules inside e.g. able to cast magic, see dragons, catch pokemon stuff like that. The story world is shared across the world, ie, like a massive multiplayer – person A going into Story 1 and person B can find person A inside Story 1 when he dive into the world.
Limitation:
1. Only able to dive into story that are concluded, have no sequel and exist for at least 100 years
2. Still require food, water. Food and water can be from the story world.
3. Once inside the story, the time will flow as per normal. E.g. people diving into the same story after a real world week, you will be inside the story for a week
4. Diving into the story world just require you to remember the world and 15mins of “channeling time”
So the question is this, how do we prevent the decay of civilization due to people staying in the story world instead of coming back to the real world?
[Answer]
**Base scenario**
People need to get out to eat and drink (and pee and poop). The same may be true for healthcare, they will need medicines, and exercise.
This means that there would still be demand for these things in the real world, and so there are people willing to pay for them... and people willing to be paid for them. So people will still have jobs in the real world.
---
**Loophole scenario**
If what happens to the body in the alternative world happens to the original body - [as stated in comments](https://worldbuilding.stackexchange.com/questions/32718/human-able-to-go-inside-alternate-world-how-to-prevent-decay-of-civilisation#comment87870_32718), that may create a loophole that allows to eat and drink inside the alternative world to stay alive. You said that you cannot bring objects from the alternative world, so maybe you cannot take out nutrients from meals, so you get back to the base scenario.
---
If you choose the loophole scenario, then the bodies are somehow linked, and food in the alternative world is food for the original body too...
* By the loophole you can eat something in the alternative world and poop it in the real world.
* If the original body is injured I would expect that to be reflected in the body in the alternative world.
* A person could sustain itself within an alternative world... and maybe use magic from that alternative word to prolong their lives! Cure any disease!
Some alternative world would be preferred over others. You would one worlds that has prosperity and safety, so they can:
* Give food to everybody.
* Give healthcare to everybody.
* Serve as communication channel.
Why is that decay? it looks like progress to me.
---
You said you can enter video games too, and if what happens to the body in the alternative world happens to the original body, that means that you could enter – for instance – Minecraft※ and have virtually endless farmable land to produce food to sustain the world. Or find a story with something like the [Sustaining Spoon](http://www.dandwiki.com/wiki/SRD:Sustaining_Spoon).
※: Minecraft is not 100 years old, no video game is. However, a government could have a long term project to create such worlds. If such extensive and abundant worlds doesn't exist, then people would NOT be too much time in alternative worlds anyway.
---
If what happens in an alternative world is persistent, then you can transform those worlds. I can imagine conquer efforts to be put to some alternative worlds. For instance, Ambrosia, Aguamiel and any Fountain of Youth are high value targets.
Of course, there is no currency that can be moved from alternative world to another (except by the poop hole)... but you can give a better life to yourself and your people if you have power in one of the alternative worlds.
---
**War**
Once we have a situation when governments are taking control of alternative worlds, we can consider that they become part of the territory. But also means that they are a frontier to all the other countries.
Consider – for example – that France is in control of the world of the Wizard of Oz. Anywhere in the world where people know the tale of the Wizard of Oz, they could try to enter that world, and so they would be stepping in french territory. Even unknowingly.
So, the government will need to have military presence in the alternative worlds to prevent them to be overtaken by opposing factions.
---
But that is not the only way to attack. You could target the real bodies of the soldiers that are in the alternative worlds. So defense in the real world is also needed. This means that – regardless of the benefits of the alternative worlds – you wouldn't move all the population to the alternative world permanently. This means, that even in this scenario, you will not have cities where everybody is immerse in the alternative worlds.
Long term strategies may include the destruction of copies of a book (or other media) to prevent others from entering. Having a selective group control the access to the only copies of a book, allows to control who is granted access to that story (which is done by allowing them to read).
Of course, you cannot make people forget the stories they already know, but new generations will not know them.
---
Note on oral tradition:
We have talked about stories being confined to physical media. But there is also oral tradition. If we allow the retell of a story to allow access, then we need to consider what happens as the tale is transformed.
When retold, some details maybe lost or added to the tale causing it to be slightly different. I would expect that that means that it is creating a new story – which is not 100 years old – and so it doesn't grant access – unless retold verbatim.
---
Note on translations and adaptations:
Since they are derived works, they could be independent to the original. That is consistent with the rule of verbatim reproduction. If we consider that to be the case, then they need to be 100 years old to be accessed. That means that if you access the Never-Ending Story it is not the same as entering La Historia Sin Fin.
The alternative is to allow canons, but there is no reference to say what is considered canon and what not. If we consider something like "whatever the original author consider canon", then them changing mind may cause drastic effects in the alternative worlds, of course it is to be expected that after 100 years most of them will be dead... but if those alternative worlds can prolong one's life that may not be the case.
Replacing the 100 rule with a "death author" rule, means that you may consider to sacrifice an author to create his world (which might be interesting to explore). But as stated, a book that expand on another is creating a new world instead of adding to the original one.
[Answer]
Sounds like a movie I saw. Sounds like a few movies I’ve seen. “Ready player one” and “Logan’s run” “matrix” and a few Greek philosophical stories among a ton more. I list them here so as not to plagiarize them which would defeat the purpose of creativity.
If the world really could do this we wonder what is the point of being alive? If the evolution of humanity has come to a point where everyone can exist inside an imaginary world while the real world is perhaps run by machines or some trained animal, then these irrelevant souls, (compared to what humans believe about themselves) could or would in essence become gods. And this in itself is a contradiction of the story where it would become more relevant to be the ones who perpetuated this imaginary world. Which in essence becomes a moral question and a pragmatic question. But anyway.
I imagine in this world one can taste and feel and everything so it does not matter how real food tastes compared to the imaginary food etc. etc. and sex and love and even creativity. But now the world is saturated in “absurdism” where nothing really matters. So to keep the real world running, somehow the virtual world can and will appease the real world in its virtual mechanics of behavior. Where what is done translates into the real world as a supporting action, like ranching and gardening and building. But maybe that too has already been done, or is on its way.
Perhaps the answer dwells inside some hidden military agenda. That divides itself by what becomes meaningful to the individual. But where is the evolution here? Has it been forgotten? Especially in that when mankind genetically alters or breeds or selects or even experiments with nature, in the end, if the plug is pulled, or the world is hit by a catastrophe, is mankind/womankind capable of existing? Way out on a limb here.
So in “deterioration” of civilization really becomes irrelevsnt because civilization is now virtual. And when things are virtual they no longer are capable of growing. So there must be a process where one must grow to survive, if not develop some attribute that allows them to be allowed to exist after a certain age. But who decides this? And is it actually insituted correctly? If the world is a evolution as compared to a human progression then the best answer is to find a symbiosis between the three parameters; virtual world, hidden reality, nature. So now is there any motive which can be seen outside of the transformations? And how is it recognized? Especially by a society content to follow an already established and omnipotent system? Or is the virtual world a “Rorschach’s test” of some kind for the admittance into the real one? But again, here it is the same as being in a primitive world. One without true logic and run purely on a majority emotion that actually contradicts its own prerogative. But I won’t expand on that.
] |
[Question]
[
In this alternate scenario, for six to ten years, latitudes as far down south as Chicago experience eight to nine months where the daily high barely reaches zero Fahrenheit (−18 degrees Celsius).
The steel of the skyscrapers in this alternate scenario is also different, with carbon consisting of 2.5% of the overall composition.
Now the question is, how does steel react to ice? Does it rust? Crack? Harden? Or something else? And how would a decade of endless cold affect the skyscraper in a preferable Life After People?
[Answer]
8-9 months where the temperature doesn't get above 0°F? Sounds a lot like Chicago!
Seriously though, it wouldn't do much. Steel does lose strength and become more brittle in really low temperatures, so that you wouldn't want to use a steel hammer at -40. But if it's just sitting there the cold isn't going to affect it much.
Parts of Alaska and northern Siberia in winter generally has worse conditions than what you describe, though those places don't usually have large cities either...
The hard part would be when the weather started to warm a bit, and you get the expansion and contraction going on, the snow and ice melting, etc.
The freeze thaw cycle is what causes the most problems, as water gets into cracks and then expands when it freezes.
6-10 years... without maintenance? Probably get some broken windows, and the steel would start to rust a bit if enough water got inside the buildings, but you probably won't see skyscrapers falling down.
With people keeping the place up? You won't see much difference.
] |
[Question]
[
[How much blood does a vampire need?](https://worldbuilding.stackexchange.com/questions/17087/how-much-blood-does-a-vampire-need)
[Could a humanesque creature derive all its nutrients from drinking blood?](https://worldbuilding.stackexchange.com/questions/2526/could-a-humanesque-creature-derive-all-its-nutrients-from-drinking-blood?lq=1)
Both these questions have some good answers and my question is based off them both...
* Would there be a difference for the type of blood, such as if a vampire drank AB+ blood, would he gain something more then if he drank O+ blood.
* What about negative blood?
[Answer]
The simple answer is no, not in any meaningful way.
If you read this article: <http://www.todayifoundout.com/index.php/2013/06/how-blood-works-and-the-difference-between-blood-types/>
It gives a good introduction to blood types.
>
> There are 8 main types of blood separated into 4 groups. The groups are A, B, AB, and O. They are grouped together by the presence or absence of what is known as an antigen. Antigens are substances within the blood that cause our immune systems to create antibodies. These antibodies then kill anything the immune system thinks is a threat. The specific antigens that create the different blood types are found on the surface of red blood cells and are known as type A and type B. They’re further separated by the presence of another type of antigen known as rH factor. If you have this rH antigen present, you’re considered positive, if not, you’re considered negative. Someone that has type A antigens and rH factor is considered to have type A+ blood. If you have both types of antigens and no rH factor, you have type AB- blood. If you have no A or B antigens then you are type O blood.
>
>
> All of this matters because of those antibodies your immune system creates. Someone with type A blood will have antibodies for type B, and someone with type B will have antibodies for type A. Type O has antibodies for both A and B. If you were to give type B blood to someone who was type A, their antibodies would attack the type A red blood cells causing very unwanted side effects, including possible death!
>
>
>
As you can see from this description the only difference is in antigens within the blood that identify it as being yours or not. These are too small to have any nutritional effect.
The only way blood type may be significant is if the vampires are somehow susceptible to or need those antigens. For example if a vampire has recently drunk blood of one type and then drinks another the white blood cells from the first may fight the antigens from the second. If they are directly using the blood in their systems then they would need it to be compatible with their own antigens.
This is unlikely though as most digestive processes are going to break down the antigens and you would expect vampires to evolve the ability to process any blood group.
] |
[Question]
[
I'm currently trying to create a science fiction planet and get an idea of the map in my head. Am I correct in my assumption that most countries have a firm mix of Rural and Metropolitan areas - so that you get "clumps" of businesses and homes in the metro areas, followed by large areas of suburbia outside of these more built up areas, with huge swaths of farmland or wilderness outside of this?
Seems pretty obvious to me, but I'd not be certain of this. Sources would be good, just so I can put my mind at ease!
---
Edit:
Thanks a lot so far for the help! I was assuming a modern level of delveopment, colonising another planet, hence my direct implied comparison with America's suburban sprawl, but I must admit I hadn't thought of slums.
[Answer]
The answer really is "it depends on the country". There are different kinds of rural and metropolitan areas. How do people live in rural France and how do people live in rural Mongolia? Is living in downtown Singapore really the same as living in a favela in Sao Paulo?
For example you mention that your assumption is that most countries have suburban areas. Suburbs (in the North American "sprawl" sense) isn't really a phenomenon common to all countries: <https://en.wikipedia.org/wiki/Suburb>
Here is a list of countries by the ratio of urbanization (also has present ratio of urban population):
<https://en.wikipedia.org/wiki/Urbanization_by_country>
But, the numbers in the above table don't tell you much about and how the place actually feels, so try using Google Maps and Streetview and "visiting" the places to complement the table. Try starting downtown, pick a road and start clicking down it until you are in the countryside :)
If you are looking for a really good source on "how to draw a map" of a world, check out the Dungeon Master's Guide for Dungeon's and Dragon's 5th edition. Its setting isn't science fiction at all, but it has very insightful and concrete discussions on how to draw/write a map of your world. For example, it describes how you would expect villages to clear most of the immediate woodland for farmland, and in the centre of villages there would be a nobleman's keep and his soldier's barracks that would keep their lands safe from invaders in exchange for tax. Another town's purpose could be as a trading hub at a river or crossroads of two large roads, and there would be less farmland surrounding that town because it can get food by trade.
The point is that if you think of who is in your world, you will be able to easily understand what people living there would do to its terrain, how they would build their cities and use resources. You won't have to design your world, you can let its inhabitants do it for you!
] |
[Question]
[
I was making a planet for a game and I was wondering how the world would be affected if it never had salt water, but instead a huge fresh water supply. Then I thought about what it might do to the Earth.
Basically what would be the differences on Earth without salt water, or would it be relatively the same? How would the life on Earth be different? How would this affect the weather?
[Answer]
Life on earth is based on a salt-water metabolism: we all carry around salt-water inside us to bathe our cells which evolved to expect that environment. So, with only fresh water, evolution would have had to happen in a completely different way: basically you're looking at rewinding the clock 4 billion years and seeing what happens without sodium and or chloride. My suspicion is that the various chemical processes which are running all the time in our cells could be done differently, with different elements, and you would get life which was broadly similar to the life we know, until you got down to the level of biochemistry. However, maybe the dependence on the alternative chemicals would push life in a completely different direction.
Basically you're looking at a total reboot of evolution, from the bottom up, and it's quite tricky to speculate what you're going to end up with after that.
EDIT - i forgot to think about weather and geology. I'm not particularly knowledgable about meteorology, geography and geology, but my *guess* would be thus:
The current state of the earth's physical geography is due to three main processes: rock formation, plate tectonics and weather. The rocks are formed, smashed together/pulled apart on the big scale by tectonics to make mountain ranges and valleys, and then weather erodes the rocks. In addition to this, tectonics and perhaps other geophysical processes move landmasses under and above sea level over huge time scales, so you have land that used to be on the sea bed now forming the earth's walkable surface, etc.
Since water evaporating from the sea doesn't take the salt with it anyway, the weather wouldn't be very different. In other words, i don't think that the oceans' salt content plays much part in the Earth's weather, because i don't think there's much salt in the atmosphere. I doubt that the salt content of the rocks plays much part in tectonics either. So, the only remaining aspect of the earth's surface which could be affected by the removal of sodium and/or chlorine would be the actual rock formation: perhaps we would have different kinds of rocks - in particular, we might have a smaller range of crystalline rocks in existence. But, i suspect we would still see the same broad processes, wherein tectonics and volcanoes make mountains, and the weather smoothes them out again, etc, and you have things like topsoil and silt and other "stuff" which change our planet's land surface from a bare rocky landscape into a softer "earthy" terrain which can support plants etc.
[Answer]
Actually, life evolved in (almost) fresh water. All the salt in today's oceans has weathered out of rock over the nearly four billion years since the steam clouds first condensed. On the other hand, at that time there was no oxygen atmosphere. If evolution had run much faster, your land-dwelling animals would have nearly freshwater blood, but they'd also have to breathe methane.
The salt levels in our blood that our metabolisms maintain almost certainly reflect the salt levels found in the oceans at the time some fishes evolved into air-breathing amphibians and left the oceans: rather less salty than today.
[Answer]
You probably will have to have *some* salinity in the larger water bodies because all vertebrate life forms (including fish and cetaceans) have a nervous system dependent on sodium/potassium channels. Not having any sodium at all in the waters would mean you cannot have fish there. Not having fish means you cannot kickstart vertebrate evolution there the way it happened on Earth.
All of which translates to say that no salinity in oceans or rivers (just a very minute level is required btw) means no backboned life on that planet.
] |
[Question]
[
For my WIP's setting I'm using a variation of the [Sky World](http://tvtropes.org/pmwiki/pmwiki.php/Main/WorldInTheSky) concept.
The cosmos looks very similar to the [Astral Sea](http://forgottenrealms.wikia.com/wiki/Astral_Sea).
The shape of the cosmos akin to a torus and filled with a silvery ether a thin, cool, omnipresent plasma. The cosmos has seven nested [layers/dimensions](https://en.wikipedia.org/wiki/Matryoshka_doll) of which only the fourth has human(oid) tolerable conditions. The mortal races dwell on [living island](http://tvtropes.org/pmwiki/pmwiki.php/Main/FlatWorld) enclosed by Shrouds,a force field generated by the islands, that in addition to being a defense mechanism trap a breathable atmosphere.
The axis upon which the cosmic torus rotates is the Empyrean, the source of heat,light and the basic building blocks of matter. It is visible no matter what layer one happens to be on, though the further one is from the Empyrean, the dimmer it becomes. The natural ebb and flow of the Empyrean's power creates a day/night and season cycle on a cosmic scale.
Despite the very fantastical nature of the setting I still would prefer to only handwave or say "cause reasons" when it is absolutely necessary. So I'm asking the question "how do Weather and Regional climates work on a Flat world"?
[Answer]
Without magic, it's going to be extremely dry. Unless you have some ocean balls floating around.
If there is no gravity outside the shroud, it means that you won't get humidity or anything form the outside. Otherwise, the Astral plane is infinite. Where is the star exactly? Normally, the star would heat the surface below and hot air would rise. But that does not make any sense in a place like the Astral plane where the light comes out of nowhere. No matter where you are, your always at the same distance and the same angle compared to the source of light. It means that all places would receive the same quantity of energy and I doupt there would be any predictable movement of air masses.
Back to your islands: if they want to live in something wetter than the Atacama desert, they would need a large (way larger than the islands) supply of water lying around. That water, will evaporate with the energy from the "light" and will fall if the temperature of this air mass gets colder. The problem I see here is that you have no temperature differential. On Earth, the air gets colder when it rise/encounter a cold air mass and that is when you have rain. But in your world, the temperature would always be the same, unless you have a day/night cycle or unless the islands move in a way that one would be in the shadow of the other.
The other thing that could make it rain is with a different albedo. If one island is white for example, it will reflect more light than a dark one, it absorbs less energy and will be colder. I'm not sure how strong this would be.
My best advice would to use irrigation, if you have water.
[Answer]
In the real world, the fact that sunlight emanates from a single point in our sky makes it possible for life to exist by allowing it to dissipate the suns free energy (low entropy) by radiating it away into space in all the other directions as infra-red radiation (high entropy). As Vincent says, if all sectors of the sky emanate the same background level of radiation this thermodynamic setup becomes impossible along with life.
However, happily that is not the case in your world, since you have identified a point source of energy (the Empyrean), and a place to send the waste heat, the abyss. Obviously a bit different to our universe but some similarities are there.
One way to get more interesting weather is to remove the impermeable shroud and instead place a small black hole (or something similar) in a sealed compartment in the bedrock of each island, which will create gravity and the ability to capture an atmosphere. Now if you allow your islands to float within a ring of gas which exists within the torus and which is somehow kept from escaping into the abyss (see Larry Nivens 'The Integral Trees' for a similar concept, see picture), then you could have weather patterns circulating through the torus somehow and which pass over the islands.
[](https://i.stack.imgur.com/jmdhr.jpg)
There will be many many problems with this scientifically but you could use parts of this scheme to create something that is at least somewhat internally consistent.
] |
[Question]
[
As part of [my Worldbuilding experiment](https://worldbuilding.stackexchange.com/questions/22688/how-long-will-it-take-to-form-a-new-dialect-and-language-in-underground-steampun), I'm creating a steampunk world. I intend for most of the technology to run on classic steampunk mechanisms - mostly mechanical contraptions.
However, electricity would be of some use to the society, particularly for things like lighting deep underground. Is it likely that a(n) (underground) steampunk society would discover electricity and develop it such that it would become widespread?
Keep in mind that this is set in and around the year 1895, in underground London.
Part of the reason I'm discussing the adaptation is that a steampunk society this far advanced might have developed very efficient ways of power transmission (?), so electricity might not be as big a leap for them as it was for us.
---
I've read the *Everness* series, which partially focuses on a steampunk society with electricity - or "electropunk" - but I'm not convinced that a society would develop like this.
[Answer]
**Yes because the requisite ideas and machines were already available in 1895.** [Steampunk](https://en.wikipedia.org/wiki/Steampunk) is generally held to be be in 19th century Victorian England or the American West at the same time. The 19th century saw a huge leap in understanding and application of electromagnetism.
The first real electric motor built by Prussian [Moritz Jacobi](http://www.eti.kit.edu/english/1376.php) started operating in May 1834 started operation. The three phase electric generator came a few decades later:
>
> The years 1885 until 1889 saw the invention of the three-phase electric power system which is the basis for modern electrical power transmission and advanced electric motors. A single inventor for the three-phase power system can not be named. There are several more or less well known names who were all deeply involved in the inventions (Bradley, Dolivo-Dobrowolsky, Ferraris, Haselwander, Tesla and Wenström). ([source](http://www.eti.kit.edu/english/1376.php))
>
>
>
Edison applied for a patent on "[Improvement In Electric Lights](http://www.google.com/patents/US214636)" in 1878. He had bulbs that would last 1200 hours by 1880. Longer lasting tungsten filaments didn't show up till [1906](http://www.bulbs.com/learning/history.aspx) though. The first flourescent lamp appeared in 1901 by [Peter Copper Hewitt](https://en.wikipedia.org/wiki/Peter_Cooper_Hewitt) so it wouldn't take much to handwave that forward 6 years. (Just cover your eyes. This early lamp had significant UV output.)
All of the elements required for electric underground illumination are present in 1895 without any special handwaving or alternate histories. If this question is for a giant underground city under London, then this creates a very large market that would motivate inventors and manufacturers to create better products on larger scales.
[Answer]
Running lots of coal powered steam engines (what are all these mechanisms being run?) in a mined out cavern complex seems very risky - not only directly from fires and explosions in confined spaces, but also for environment concerns (consuming oxygen and emitting exhaust). Even without a lot of combustion going on in London Below, the ventilation system would be truly incredible for any significant population to be living in a giant coal mine. This could be mitigated though just using massive boilers on the surface transmitting the mechanical power down through the caverns via cables or perhaps jerker lines, but not really any steam engines in the underground (much less basic things like cooking stoves or fireplaces).
I would expect that electrification of their town would be significantly more advanced that the rest of the world - the benefits of eliminating combustion in such enclosed spaces would make electrification a priority. If they had factory equipment, rock crushers, etc. which required significant amounts of power, I would expect it to be located at the bottom of a major vertical shaft through which mechanical power could be transmitted from a power plant in London Above. Any smaller application (household or office use), or anything down a corridor which did not have an easy line up to the surface, would probably be electrical. They would be pioneers of electrification out of necessity of eliminating as much combustion as possible.
[Answer]
These are just alternate time lines where the history is what ever it needs to be in order to support the world as it is. If it's not possible, then you just change what ever you need to change in order to MAKE it possible.
"steam punk" means that they have advance steam engine machines, but not electricity.
What does "Electro punk" mean? They have electric motors but not electronic computers? Or possibly they need electric cars because they don't have petroleum? In other words, they have some arbitrary set of technology and continue making inventions within the limitations of that technology, pushing the boundaries of what can be done within those limitations.
You need to be more specific about what technology they DON'T have because currently, almost EVERYTHING we use is already powered by electricity.
I'm guessing that you just want some secret laboratory in the sewer that is full of Tesla coils? And some semi-crazy scientist who believes that electricity is the future? This sounds like the setting of the original 'Frankenstein's monster' storey, which is not really refered to as "electro-punk" as such. It was probably based of actual egocentrics who really did exist.
] |
[Question]
[
This question is pretty simple. In a world where about 7% of the population have functional wings, how would buildings (such as offices, schools and homes) differ? I'm looking for ways that would allow easy take-off and landing without alterations that would take up large amounts of space and money, such as large landing pads and runways.
The wings are:
1. On average, 7ft each (for a 14ft wingspan)
2. Hairless and featherless- the resemble bat wings in the colour of the person's skin, but they can be dyed or tattooed.
[Answer]
7% of the population isn't very much, but some places would probably try to accommodate them. You definitely wouldn't need a runway, but most likely buildings would need some sort of open-ish area to let them take off and land. A more accommodating skyscraper might have ledges every couple dozen floors, to let the flyers land close to their desired floor, instead of having to land on the ground and travel up. They would also provide a great way for flyers to take off. It would, however, not be very cheap. So I believe the most common change would be to merge a parking space or two, fill it will dirt, and reserve it as a landing zone for flyers.
If, however, the country this is in has a legal system similar to the USA's, then it might get more complicated. The landing zones might be very soft and squishy, to try to preclude anyone from getting hurt even if they land badly, the ledges might not exist, to preclude the possibility of someone landing poorly and falling off - and their family suing the building owners for not having made it safe enough. The legal aspect would also get interesting (no-fly zones, police searches in which the criminal could have simply flown away).
All buildings which need any sort of security would have to completely change how they operate; they can't just rely on a tall barbed wire fence, but now also have to deal with the possibility of invisible (radar-wise) aerial intrusions. Maybe a giant cage built over the building would be sufficient. It also would make being searched much more difficult - if people can hide things in their crotch and try to sneak past security, imagine everything someone could fit inside their folded-up wings.
I also imagine flying would take a good amount of exertion - if you're flying to work, and your job requires you to wear a suit, then you'd probably have to carry it with you and shower/change once you get there, and so buildings trying to accommodate flyers would need to make that possible.
A different idea for taking off might be a big slingshot, but that would probably only be cost-effective in places like big cities where parking space is a premium. Though again that probably would never happen if the building has to worry about civil lawsuits. Also, flying in big cities might not even be allowed, given how easy it'd be to crash and cause damage, or flap around next to a windowed building and spy on/bother the people inside.
Smaller places not in cities would probably have more roof access, from which a flyer could take off.
Also, unless their wings are really compact when not extended, you'd probably have to provide larger doorways, hallways, taller stairwells (more clearance space above their head), and completely differently designed toilets (there'd have to be room for their wings between the seat back of the seat and the wall/tank/piping)
If the people have similar reflexes when startled to other things with wings (i.e., they flap their wings to keep balance) then they might not even be allowed in the same public crowded spaces as everyone else - imagine one of them tripping in a crowd and shooting their wings out as a reflex. People would get hurt, it'd cause a huge disruption, people might get angry. Museums, jewelry stores, and similar places might not even let them in without some sort of clothing that prevents their wings from unfolding, to protect the items on display.
[Answer]
Something else to consider would be the cultural implications. Perhaps the winged humans are better suited to travel, and become more successful as a result, meaning that catering to them becomes a status symbol (the best restaurants and hotels are on the high floors of buildings with only access through the landing pad).
Or possibly they are well suited to construction work, making them sought after, but considered to be "lower" than those without wings. Might make catering specifically to them to be considered "uncouth".
Worth thinking about the extended ramifications of having physically different people integrated into society in a mature fashion.
] |
[Question]
[
*Disclaimer: I'm not a native speaker, so please excuse any mistakes. If a word seems out of place or you don't understand a sentence, please post a comment and I'll explain myself to the best of my knowledge.*
Ignoring the fact that it would be extremely hard to build and operate the facilities to produce these compounds, and assuming that every product that could be theoretically made with carbon (Ex. carbon transistors) can be produce on site, **which materials needed to maintain and expand a space station could be replaced by carbon, and which not?**
The reason I'm asking this is because in my world this station is orbiting in an asteroid belt. According to what I read about the topic, C-type asteroids are common and easily identifiable. I assume that specific metals, on the other hand, would be rather hard to find without exploring several asteroids, making importing and recycling them more efficient.
Keep in mind that:
* Materials for which only a very small amount is needed could be imported and stored, and can be ignored in your answer.
* Food, air and water are not counted as 'materials needed to maintain and expand a space station could be replaced by carbon'. The problem of power generation has already been solved too. This aspects can therefore be ignored in your answer too.
[Answer]
As a building material carbon could conceivably be used for *everything* on the space station, because carbon is such a versatile material.
Carbon fibres are already used to make very strong and lightweight structures, and the basic structural spine of the station could be built this way (I am going to assume an ISS like structure, but with suitable tweaking you could build to the shape you like). Carbon finer can also be woven into cloth, so inflatable habitat modules such as the ones being pioneered by Bigelow Aerospace are possible. So we have the basic structures.
More advanced carbon materials like Graphine or carbon nanotubes have been demonstrated as energy conversion devices, making the basis for solar cells and superconducting "cables" to move electrical energy around. Computers, communications devices and other electronics can also be made from various forms of Graphine and carbon nanotubes. A bit of "cheating" may be needed in the form of "doping" the materials with small amounts of other elements. These materials may also be used for more mundane purposes like making pipes for plumbing roll the graphite sheets into a tube). Graphine may also be used to make high efficiency filters, making a graphite sheet with molecular sized holes just large enough to pass the molecules you want can be used to separate pure water from contaminants, or keep CO2 on one side of the barrier for the air purification system. A form of carbon called Bukministerfullerine (C60) has 60 carbon atoms arranged like a soccer ball, and can theoretically be used to store gasses like Hydrogen inside the molecular matrix, which might be useful for the astronauts.
Mechanical parts will need to move, so carbon in the form of Graphite may be needed to form sliding and rotating interfaces and bearing surfaces for your space station.
A few things will need to be kept in mind. Most forms of carbon described have very high *tensile* strength, so the comparisons to earthly construction is balloons and tents, rather than the Eiffel tower or Great Pyramid. For high compressive strength, you will need to go to the expense of changing the carbon into diamond, which is also extremely good as a heat conductor and can also be used as the basis of semiconductor materials as well.
Your space station will be possible, but you will need to take some fairly impressive machinery to mine the carbon materials and then process the carbon into its various forms to make building materials. You should also keep the need for other elements to "dope" various carbon materials to change electrical and other physical properties if you want to make solar energy systems, cables and comms wire or have the carbon take on other properties. In the long run, a colony on the asteroid itself will become wealthy by setting up the industrial plant needed to mine and process carbon into the various forms useful for various projects.
[Answer]
Even if an asteroid were largely carbon, it would probably contain significant quantities of other elements as well, so that's helpful. Asteroid fields are never as dense as what we see in the movies. Many spacecraft have gone straight through the asteroid belt and didn't even come close to an asteroid. The average distance between asteroids is 93 million miles. Mining multiple asteroids would take so much energy and reaction mass going back and forth that it isn't economical.
(<https://physics.stackexchange.com/questions/26712/what-is-the-average-distance-between-objects-in-our-asteroid-belt>)
Your best bet for a space station is to find a really big asteroid (larger than 1 km in diameter) and burrow into it. By digging caves deep into the asteroid, your colonists can do a number of things at the same time. The structure will be sturdy. Air sealing is less of an issue. Thermal control systems and temperature extremes are not an issue. Cosmic rays are less problematic. The low gravity environment makes moving masses of rock and ice very easy.
] |
[Question]
[
**Closed**. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers.
---
**Want to improve this question?** Update the question so it focuses on one problem only by [editing this post](/posts/21971/edit).
Closed 8 years ago.
[Improve this question](/posts/21971/edit)
The troll leader calls you to his throne and says "troll general, I must ~~steal~~ ~~dominate~~ acquire the world. As an expert in troll warfare, you must draw up the plans for this acquisition."
So you have a population of about a 10 million trolls. The trolls have the ability to use *troll logic*. Troll logic is where you use reasoning with only slight flaws, but results, that, well, normally couldn't happen. At least if you're not a troll.
The basic Troll logics range from Troll Physics to Troll Sociology. Generally, the magnitude of troll logic you can use depends on the purity, as defined [here](http://xkcd.com/435/). Basic infantry can be trained in enough troll physics that they can fly a magnet pulled vehicle, the entire troll population can only produce enough troll sociology to produce high-quality, but mundane, propaganda.
* Troll Physics is the brunt of what the trolls use. It is powerful enough for various weapons and means of transportation.
* Troll Chemistry is about as powerful as alchemy.
* Troll Economics would allow a secret agent troll to gather wealth while on a mission, but isn't strong enough to crash the economy of a country
* Troll Psychology is about as powerful as Jedi mind tricks
* Troll Sociology is powerful enough to produce propaganda, or similarly powered stunts.
* Various other fields, scientific or not, fall in various places. There is Troll history, Troll international law, Troll politics, etc...
+ In fact, you are an expert in Troll warfare.
Also, how well troll logic is used influences its power. Out-of-universe, the power is proportional to the magnitude of the emotional response it causes an expert in the field (humor and disgust are both fine).
The difficulty of a troll logic task is determined by the magnitude of the effect. No matter how much troll physics you have, you probably couldn't deorbit the moon.
By the way, you may be wondering about mathematics. There is a troll version of mathematics, but it isn't called troll mathematics. Instead it is called INSANE TROLL LOGIC, the most dangerous kind. It so dangerous, that is usually on used as a last resort.
* INSANE TROLL LOGIC is extremely powerful. A INSANE LOGIC TROLL possibly *could* deorbit the moon, with backup from physics trolls.
* It is also **dangerous**. As well as deorbiting the moon, you could accidentally turn all infantrymen into Justin Bieber, or blow up your base via the [principle of explosion](https://en.wikipedia.org/wiki/Principle_of_explosion).
* INSANE TROLL LOGIC can use the powers of any other troll logic.
* The safest form of INSANE TROLL LOGIC are [paradoxes](https://en.wikipedia.org/wiki/List_of_paradoxes) that confuse even mathematicians, but even these would only be used for a good reason.
---
Okay, so my question is, troll general, what way to over the world is most likely to succeed. Remember, an answer must be in a *Troll-esque* dialect. Explain the troll logic behind each thing you do.
[Answer]
Troll General Ugg know **red** thing go fast.
Troll General Ugg know INSANE TROLL LOGIC bad.
Troll General Ugg know world leaders like MAD.
Troll General Ugg use Troll psychology to talk to world leader and convince them of Troll logic.
Troll General Ugg get INSANE TROLL LOGICIAN to work out equation for Armageddon.
Troll General Ugg sedate INSANE TROLL LOGICIAN .
Troll General Ugg paint INSANE TROLL LOGICIAN **red**.
Troll General Ugg point out to world leaders that, should the insane troll logician wake up, he's going to very, very quickly work out the ideal equation for Armageddon, leading to the world ending. Or possibly just turning into strawberry Angel Delight. This will of course convince the world leaders of the futility of continuing to oppose the great Troll Leader's wishes, leading them to rapidly capitulate and submit to his wise rule.
???
Troll General Ugg Profit...
] |
[Question]
[
The core of this question is this: Given what we believe we know about the requirements for a tool-using, space-faring race to evolve, how viable would a species that has a hybrid exo/endoskeleton be?
Believed requirements for a tool-using, space-faring intelligent species:
1. Dextrous manipulator appendages, at least two (i.e. hands)
2. Upright structure to keep manipulator appendages free for use (or some other means of keeping the 'hands' free)
3. Centralized nervous system (for more efficient processing)
4. Terrestrial: Need controllable heat sources to make advanced materials. i.e. fire
5. Varied sensory suite located near brain, focused on vision or vision-like sense
6. 'Head' likely located high above ground to allow greater field of vision
7. Medium-Monkey-sized or larger (need to be big enough to allow for complex brain)
8. Capable of withstanding gravity-escaping accelerations
9. Evolutionary need to develop tool-use (apex predators and 'tank' animals have no need to be clever to survive, their physical structure is enough)
I am aware of the limitations and restrictions facing the use of a pure Exoskeleton, including but not limited to: temperature regulation, ability to self-repair, thickness/weight constraints as something gets bigger, and materials concerns. So a pure exoskeletal creature would probably not reach a size great enough to develop intelligence. So, my thought moved to a hybrid: a creature with a mixed endo-/exo- skeleton (like a turtle).
The basic design in my head is this: exoskeletal armoring covering much of the body, particularly the vital organs. I'm not thinking of an 'upright giant turtle' with a shell it can retract into. I'm looking at a creature that has an exoskeletal primary body that is thick enough to withstand day to day abuse, which is fused to an endoskeletal structure that is used within the dextrous manipulator appendages, mobility appendages, and any other 'jointed' location that needs freedom of movement. Those appendages are likely covered in a form of flesh or scales that allow a freedom of movement not permitted by a thick exoskeleton. The basic image in my head is similar to that of plate armor. (note: I'm not talking about an endoskeletal creature with natural armor. Anywhere there is armor, there is no endoskeleton apart from where it connects.)
My mental concept of them seems sound...like something that could actually function and survive, though I have concerns about whether or not a creature with such effective natural armor would even need to develop tool use.
So, reality-check time. Am I missing anything? Is this design for intelligent life sound according to what we currently know of biology, evolution, and physics? Could such a creature survive, and then make it to space?
[Answer]
The closest thing I could suggest is looking at the family of cephalopod molluscs, which includes octopi and squids. At some point in their evolutionary history they shed their shells and became much more mobile and intelligent as a result.
Now one of the limitations of their body plan is there are no rigid attachment points for their muscles, which allows them to do things like squeeze in and out of bottles (for octopi) and assume streamlined shapes for high speed "jet" flight (squid). These are very advantageous in the oceanic environment where they live, but if a similar creature lived in the intertidal zone and became amphibious as a result, this might become a disadvantage. Such a creature might evolve a partial covering over the vulnerable body but leave the limbs free, which could become a form of exoskeleton if the creature evolves further to use the hard "shell" as an attachment point for some or all of the musculature of the limbs.
This would allow the creature to assume a more "upright" posture, elevating its eyes and sense organs to give it a greater field of view, a tremendous advantage on land. As well, over the ages some of the limbs might evolve into thick, muscular "legs" while other limbs would become smaller and more flexible to manipulate objects (for example, pulling aside rocks to get at tasty prey animals).
We now have some of the basic elements for evolving intelligence, in an environment where increasing intelligence would be rewarded. If the ancestral creature was "social", living in pods or schools, then there would be another big driver for intelligence: the need and ability to communicate among themselves. To make this work towards becoming technological creatures, they would start using their cooperative powers to extend their swamps by digging channels, levees and ponds to manipulate the flow of water to their advantage, developing more complex tools, social structures and understanding of natural forces to build elaborate swamps. The last thing would be for some to move to land more permanently and discover fire.
From their ancestry (and if they retain some or all of their amphibious characteristics), they might actually be *better* with 3D environments like the air and space, and if they retain very flexible manipulator arms and tendrils, they will have less of an issue working on small items or items crammed into small spaces where human hands would not fit. OTOH, our bones and musculature would allow us to generate more force, so an alien based on the cephalopod mollusc body plan would have a hard time using human technology like screwdrivers, hammers or wrenches. Alien artefacts might be sewn or glued together, for example, and forging metal objects might be a very late development in their technology (their metal technology might be soft castings and sintered metals). This would make developing internal combustion engines, jets and rockets difficult, slowing down their ability to get to space. Their spacecraft would also have am performance issue if they are still amphibious, since the craft would need to carry a lot of water aloft (which is heavy), meaning a Saturn V sized rocket might be needed to get a single "astronaut" into space.
[Answer]
I would think that taking a turtle like animal and extrapolating it you could get something like what you are looking for. Besides weight vs strength ratio reducing in larger sections, one other large problem with a true exoskeleton is that is doesn't 'grow'. Many bugs 'shed' their skeleton and grow a bigger one (such as spiders). This also gets much more energy intensive as an animal grows. One option would be for the shell to 'split' in places to allow them to 'grow' like bark on a tree. However, turtle shells have living tissue completely surrounding the bone and continues to grow the shell with the turtle (which of course makes it not a true exoskeleton)
However, having large bones protecting key areas of the body and even more bony growths that can be used in defense or offence (say antlers!) and I think you can get something that is similar to what you are looking for. some of the plates could be like toe nails/horns (different from antlers) and grow from an area of the body to protect it.
You have turtles as a beginning example. One thing the current animals with protective shells implies though is that they are fairly easy prey, and the armor is more important than speed. But the are reasonably strong, maybe for moving all that armor.
[Answer]
Molluscs give one some interesting options but I'd personally be inclined to go the "bug" route instead, holometabolic insects go through four different life phases; egg, larva, pupa, adult. In the larval and pupal stages these insects are soft and undergo great growth and change, if we look at an insectoid with a few changes, birdlike flow-through lungs being the main one, we can have a creature of any size we need it to be with a reasonably heavy exoskeleton protecting it's thorax. This creature does all it's growing while it's still soft and young especially for the skull and thorax which are going to be the most heavily "exoskeletonised" sections because they contain all the important bits, the limbs are going to have a lighter, more flexible, shell that allows movement with the primary muscle assemblage being on enoskeletal struts. There are six limbs to play with too so you can have a pair of heavy weaponised exoskeletal arms and a pair of light enoskeletal arms with high dexterity appendages for fine tool use, or four legs for added traction and speed if they evolved on rough terrain.
[Answer]
The viability of a species is purely determined by its environment (including predators and competition) so you can't say anything about that.
However since you assume a space fearing civilisation as a given, we can also assume they have passed the point that they are dependent on their environment or that they can alter it to their needs at will.
At that point an species is viable, including yours.
] |
[Question]
[
There is a cold planet (maybe a moon of a gas giant) far out in a solar system.
It has a solid core and the surface is a thick layer of ice. Because of nuclear fission in the planet's core it is warm enough for there to be a huge ocean between the core and the ice.
Enough gases and minerals bubble up from the ocean bed to support multicellular life forms.
No light gets through the ice but bioluminescence exists.
Fire is not possible underwater therefore metallurgy and most technology would be unattainable.
The only electricity is from living things (e.g. electric eels).
Creatures can evolve 'hands' to manipulate things - intelligent crabs maybe.
The questions are:
1. Would there be any evolutionary pressure to become more intelligent or would it just be like Earth's ocean for ever?
2. If there were intelligent inhabitants who could speak and reason logically, could they invent any technology at all apart from simple things like using rocks to break open the shells of their prey.
Would there be any point in forming laws and governments or studying philosophy?
My guess is that on Earth it was the movement of life from the oceans onto the land that allowed all these things to happen. They just wouldn't happen on the planet Wetworld.
3. Can anyone suggest a way that the intelligent inhabitants could create an advanced civilisation under these conditions?
[Answer]
>
> Would there be any evolutionary pressure to become more intelligent or would it just be like Earth's ocean for ever?
>
>
>
I think it is very likely for intelligent life to appear given the condition you mentioned. They will probably look like the very weird deep-ocean creatures we have on earth since they evolved without any light and in almost the same condition you evoked.
>
> could they invent any technology at all apart from simple things like using rocks to break open the shells of their prey
>
>
>
We could think of water as a fluid and starting from this it's not much different from air. Without any generally produced light to see far away the creatures would have to rely on their own bio-luminescent light. Which is costly in term of energy so I guess this world would be very very dark and would evolve way slower than ours.
Anyway why wouldn't they have the possibility of inventing technology. They could start by finding ways to get durable light generators (even if it's implying slavery). You stipulated they have hands so they can manipulate objects and combine objects together which means they have access to tools and by extension to any tool which works in the water. They can have electricity I think if they invent a way to isolate metal from water but electricity in this world would be tremendously dangerous since they evolve in a highly conductive environment.
>
> Would there be any point in forming laws and governments or studying philosophy?
>
>
>
I would say yes. As much as here. But I bet it would be much different. They would probably see the ice as we see the sky at the difference they could "touch it" by "flying to it" unless you have some creatures incapable of swimming and stuck on the "floor".
>
> Can anyone suggest a way that the intelligent inhabitants could create an advanced civilisation under these conditions?
>
>
>
# Prehistoric age
## Fire & Light
First of all they would have to invent a way to produce energy like we did with fire. Fire is prohibited though so they certainly will use some chemical processes. If your crust is thermally active they will heavily rely on this. They need to build shelter, to produce food and to protect themselves from threats. This is totally achievable in the water.
They will produce their own light and it's very likely that slavery would be a consequence.
## Communication
They would communicate through sound waves exactly like we do since sound evolves rapidly and efficiently through water. They could create a complex vocabulary base upon different wave lengths and "sounds" like dolphins and whales do.
## Writing
They will have to invent writing so they can store information durably. This is not infeasible and they will start as we did: painting the walls of caverns.
# Steel and coal
The difficult part is to forge steel. I don't think there would be any very efficient black-smith in this world and this a real problem but we could imagine they could have access a other options we do not know like chemical smiting.
# Electricity
Like I said electricity is very hazardous in the water and I don't see how a water-proof computer would work but they might find a way - maybe by heating up water - to create little isolated gas-pockets in order to protect their appliances from the surrounding water. Those gas-pockets would very much look like our light-bulb. The environment will make electricity much more difficult I think but not impossible.
# Science & religion
Science would not be very different than ours since it's not dependant on the context but is rather a theoretical concept. I think they would consider trying to understand what's beyond the ice crust like we tried to understand what's beyond the sky. They might have the same difficulty because of religious conflicts. They will be likely to consider the Ice Crust as a god and many rituals would emerge from this, like "touching the God upon our heads" as ritual for being a grown up.
[Answer]
The question is, as it always is with evolution, and pardon me for having a shorter answer than most people, "Why would they want to?"
Of course, the answer that comes to *my* mind is "to survive." Can this creature do better than other creatures in that they can't harm it and neither does anything else? Can it reproduce as much as it wants? Is there enough food? When all those questions have an answer of "yes," then it stops needing to evolve. Consider Angler fish. Top of the food chain, pretty hardy, don't need to change *that* much. If they don't need to write to get better, they won't. If they can evolve luminescence of their own, or whatever, and it's necessary, it will get done, but otherwise not. I'd say that it would be pretty darn similar to what we have here: If you're the best in your zone, stay that way.
[Answer]
## Light
There would be no light. There would be no bioluminescence. The issue is that without light, eyes don't evolve. Without eyes, bioluminescence doesn't evolve. A catch-22.
## Not-Light
Instead of light, one might use electrical fields. By releasing small voltages and sensing what comes back, one could examine the world around oneself. If this is used, the notion that observing changes what is observed would be very fundamental for them.
Sonar or echo-location is also possible.
## Intelligence
Neural development might happen as part of interpreting the signals one is receiving. To get to intelligence, it might need to be a large creature that starts repurposing part of its neural architecture. But I could believe it.
## Civilization
If the sensory system involves projecting energy (sound or electric or anything else), then a later adaption could include weaponizing that projection. Combine that with community living and one starts needing basic laws fairly quickly. Things can snowball from there.
] |
[Question]
[
Imagine a wizard *à la* [Frozen](https://en.wikipedia.org/wiki/Frozen_%282013_film%29). He has a good control of [Cryokinetic](https://en.wikipedia.org/wiki/Cryokinetic#Elemental_and_environmental_powers) powers.
He decides to slow his aging. He considers trying to slow down his cells movements (yes, he knows about cells), but he is afraid that that would only result in maybe living longer, but at the cost of being a frozen statue.
He doesn't want to live eternally, but a few hundred years would allow him to actually do something reasonable.
**Do you think that his magic allow him to increase his life expectancy without completely rendering him a frozen statue?**
[Answer]
Absolutely, using [Sandersons' First Law of Magic](http://brandonsanderson.com/sandersons-first-law/):
>
> An author's ability to resolve conflict with magic is directly proportional to the reader's understanding of it.
>
>
>
If you are using magic, it can do absolutely anything you want it to. Anything at all. Anything. The trick is that if you need to resolve a conflict found in the story (such as why a wizard has lived for 200 years), the reader needs to understand it.
Don't worry about the mechanics. The mechanics are "magic," and that is all that truly matters. A "scientific explaination" ties you to actually knowing the physics of his cryokinetic abilities, and actually gets in the way.
Instead, focus on the reader understanding the effects of this magic:
* He should feel cold on the outside, reflecting his lowered metabolism
* He should talk in long drawn out words, reflecting that his mind is moving slower under the slower metabolism.
+ If he needs to think quickly, this is now a "challenge" for you as an author. Why does his brain move fast if his body is moving slow? This is hard enough to solve with magic, but even harder with physics!
* His interactions with others should develop like ice crystals, forming perfect seed crystals which then grow into icy lances to pierce the arguments of others.
* When the love interest is introduced to him (there's *always* a love interest), the feeling of melting should be palpable. We should feel him trying to win love with his sharp edged icy approach, feel his frustration as it doesn't work, and feel him push himself to new high [temperatures] he's never been at before.
[Answer]
Maybe he could use [Cyrogenics](http://en.wikipedia.org/wiki/Cryonics)?
This doesn't do *exactly* what you want. But it does let him stretch out his lifespan over a longer objective period, and skip the boring parts.
For example, let's say there's a large, long project he wants done that he needs to oversee at a high level. Instead of showing up every single day for 6 months, he could freeze himself for 6 days out of 7 and only show up on Mondays to check things out and make sure it's on track. So during that 6 month period he would only age ~1 month.
If he's doing research/experiments, he could set something up that will take a while and leave it to his assistants, then freeze himself and wake up only when it's actually finished.
One obvious downside of this technique is that it requires him to be good at delegation and have competent assistants who can manage things while he's frozen, but that doesn't seem insurmountable.
[Answer]
What if he used Cryogenics to slow his aging only while he slept?
He could freeze (or cool) himself before sleeping to slow down his aging, and then just heat himself back up in the morning. I'm not sure how well rested he would after sleeping in a cryogenically frozen state, but he could potentially extend his lifespan by about a third this way. (8 less hours of aging per day)
[Answer]
Nope, I don't think that it is possible to stop the movement of cells and carry on moving because then there is no energy being produced by the cell to move.
The only way I can thinkup other than cryogenics with such a limited type of magic, is possibly to prevent the damaged caused to the body by [free radical](http://undergroundwellness.com/oxygen-is-killing-us/) energy. Damage to our cells from free radicals are thought to be one of the main reasons that we age because that damage accumulates over time, so prevent it should dramaticly increase the life span.
Ofcourse its inpossible to know how long that would extend a persons life but it is a plausible explanation for a longer than regular life span.
] |
[Question]
[
Imagine a society. Every member of the society is indoctrinated in different ways by
1. their parents,
2. the education system,
3. media and
4. friends.
One can think of this society as a collection of
1. idea **senders** (when people or media send their opinions on other people),
2. idea **receivers** (when a person gets a "signal" from someone else and believes it) and
3. **repeaters** (when a person believes an idea imposed on him or her by others and then starts to spread it, thinking that the idea is his/her own).
Let's assume there is some widespread view of the world.
One could build a story around a small group of people changing the dominant view of the world by
1. sending the right amount of signals (some new idea) to
2. the right people (those, who are most open to new ideas) and
3. in the right intensity.
I've been breaking my head, how one could estimate these things. Then, I thought that there must exist some literature on these topics since there were several examples when large numbers of people voluntarily (without any physical coercion) did things, which ran against their interests, such as
* the rise of the National Socialism in 1930es Germany (including the astonishing fact that many otherwise intelligent Germans bought the Nazi slogan along the lines of *We need to defend our country, therefore we have to invade Russia*),
* collapse of the Soviet Union without the resistance of its citizens (even though the majority of them were against it) and
* the 2004 Orange revolution in the Ukraine (lots of Ukrainians believed that the politicians, which came to power in 2004 would be less corrupt than their predecessors - from everything I know from Ukrainians, these hopes never materialized and the new rulers were more, not less corrupt than the old ones).
There were also experiments, which suggest that a group of people can be manipulated into a behaviour they wouldn't choose other wise (e. g. the Stanford Prison Experiment).
If I wanted to build a world, in which a small group of people imposes its views on the majority, what theoretical frameworks and/or books could I use as a starting point (to mak it more or less realistic) ?
[Answer]
I read a lot about manipulation and mass media a long time ago, some of the things I remember:
* It is usually to try to present your POV as a new idea, rather than backing an old idea.
When you talk to someone, it is easier to sell them a "new" idea than to make them changing an already existing idea. People will often use any argument they can find (or even, will just plain ignore opposite arguments) in order to confirm their bias. If you want to introduce your ideas, make them new (this is called the Goebbels effect, IIRC).
Even if the idea is old, presenting it in a new form may improve its chances.
An example I read about was people encoraging somewhat racist audiences to read science-fiction. When the issue was, v.g., "black vs white", people had an already defined position; but in a "martian vs human" context, could be more positive to the concept of collaboration between intelligent beings.
* Do not force the idea, but stablish the agenda. All decisions in these days have pros and cons (otherwise, there would be no need for decision). Raising taxes provides better public services, but limits people freedom to use their money. So, instead of getting in a discussion about if funding public service X is worth Y tax (were either side has arguments for and against), just state the "principle" that is more important ("A nation cannot succeed without good public services" or "the government should not take away private property"). More about this in P.F.Lazarsfield's studies about the role of newspapers in elections in Elmira.
* Ideas are communicated through opinion leaders. Usually only a small % of the population is actively promoting new ideas, but those talk to other people and help changing their views. Note that the term leader can be missleading, an opinion leader could be a teacher or a office director, or a janitor who just knows what arguments ring a bell to the people he talks to. Mass media is mostly effective in communicating the ideas and arguments to those opinion leaders.
* In time of crisis and/or social change it is easier to introduce new ideas. If there is stability, you will likely be surrounded by lots of people who think similarly to you; if you express interest in new ideas they would disincentivate you from changing your opinon1. In times of crisis and changes people are more isolated so they are more susceptible to the mass media.
1: I do not mean that they coerce you, but if you tell, say, your usual friend about the new idea and they do not become convinced, most probably you will begin having some doubts about it.
About books, I read a selection of short studies in Spanish, I do not recall its title or even if the selection was originally in English (the studies were).
It included, among others:
* P.F.Lazarsfield studies in Elmira
* an study about the Goebbels effect
* an study about some WWII-era US soldiers who were shown "The Battle of Britain" film and were asked later their opinion about the course of the war.
[Answer]
You should look into [memetics](http://en.wikipedia.org/wiki/Memetics), both fact and fiction. (There is a neat science fiction roleplaying game about [a heavily memetics-influenced future](http://www.sjgames.com/gurps/transhuman/).) Wikipedia should give you the real-world links.
[Answer]
[Steven Alan Hassan's BITE Model of Mind Control](https://www.freedomofmind.com/Info/BITE/bitemodel.php) comes to mind.
>
> "...mind control refers to a specific set of methods and techniques, such
> as hypnosis or thought-stopping, that influence how a person thinks,
> feels, and acts. Like many bodies of knowledge, it is not inherently
> good or evil."
>
>
>
Hassan's model has been applied cults, human traffickers, and terrorist organizations like ISIL. It can be accomplished by both destructive and non-destructive means.
The BITE Model:
1. Behaviour Control
2. Information Control
3. Thought Control
4. Emotional Control
So far I think it's been the most scientific approach to studying effective mid control or brainwashing.
[Answer]
**Emotion: Fear, Hatred, Uncertainty, Distrust, Ridicule**
This is the absolutely necessary component for brainwashing people. It must be prevented that people could make a neutral observation, an accurate accessment of the current state, a balanced decision and finally a coldly thought out rational judgement.
*Fear*
All species have made an important observation during their lifetime: You can have a good or bad life, but death is always irrevocably fatal. For this reason alone (and it is a good reason) any threat which could cause or lead to this result is much more negatively viewed than its counterpart. If we have a drug which kills in 10% of cases and gives unbelieveable bliss in also 10% of cases, a solid majority of humans would not take the drug. So you need to have some boogeymans which press the red button in the brain. You could lose your job, you could lose your friends, you could lose your wife, you could lose your life. Don't make trouble, it is not worth the effort.
*Hatred*
Fear is nice, but how do we get fear? Easy: Your fear is legitimate, there are people out there who wants to get **you** !! Yes, **you**! There are people out there who hate you for no reason at all and every, really every action they do is born out of malice.
There are **terrorists** out there who kill innocent people on purpose for their heinous deeds. They have no similarity to heroic **freedom fighters** who fight for a worthy cause. We must support the free-loving people under the **totalitarian dictatorship** of our enemies, but naturally if our enemies are having insurgency groups in our allied states, we need an **authoritarian government** to deal with it. **Rogue state** Syria with its ruthless ally target **small, little children** with barrel bombs. [US forces and their coalition in contrast do literally everything to avoid casualties, if a bomb randomly goes off the mount and hits randomly a building with faceless people inside, it is a **terrible, tragic unintended accident**](http://www.independent.co.uk/news/world/middle-east/isis-syria-iraq-air-strikes-civilians-killed-injured-casualties-children-mosul-offensive-latest-war-a7771146.html).
*Distrust and uncertainty, ridiculing*
While the former emotions try to inhibit a rationally guided response to situations and people, the decision process itself can be targeted. Everyone knows that you are unable to make and defend a correct decision if you know nothing about the situation, so if you want to brainwash people, you must inhibit the possibility to get this information in the first place.
[**So you must poison the well.**](https://en.wikipedia.org/wiki/Poisoning_the_well) Give conflicting information. Invent own sources and erm, "remove" the original sources. Attack people personally that they are liars, make love with prostitutes and kick dogs, do not spare any mud for your sling. If some negative information comes up, it is always propaganda from (insert current enemy and irresponsible person here). Have a battery of "experts" ready who dismiss claims and ask for a "balanced picture".
If something could be very serious, try to turn it into a laughing matter. Use "conspiracy theory, bullshit, ridiculous, nonsense" and don't spare absurd comparisons.
**Mass effect (No, not that game) and conformity**.
Persons are such social animals that it is very, very hard to escape social constraints. [If you have enough persons, you can put such enormous pressure against single persons that they accept even absurd statements](https://en.wikipedia.org/wiki/Asch_conformity_experiments).
The observed love for uniformity in environment who want brainwashed people is not without reason. First, people who do not like or distrust the brainwashing message will be rebellious and therefore easier to identify and handleable. Second, the longer a person remains in a group with a conforming opinion, the more it will reaccess his personal view to the new information (This is the reason ideology likes to divide persons from their friends and family or even turn them against their former circles). Third, the leaders themselves errornously begin to assume and search evidence that their brainwashing really turned all of their people (This is the reason dictatorships could not stop to meddle with election results to increase them up to 99% instead of a more plausible 60% which would still give them the power).
**Stop your opponents from acting (Infighting, loss of social cohesion)**
One reason which seems to be often neglected in the rise of dictatorships is the *loss of social cohesion*. In the years before the fatal year 1933 there were severe street fights between communists, nazis and civic parties, each having their own strongmen. Trump came to power for the very same reason: An intense dislike between the US left and the right which seems to have deepened to hatred. In this case the public is more open to extreme views; especially because the divided groups are living in the very own filter bubble of news which only confirm the own worldview and are not able to review their opinion in discussions with the conflicting group.
Left groups are known for such severe and pointless infighting and split-ups that this was parodied by the ["Judean People's Front"](https://en.wikipedia.org/wiki/Eritrean_Liberation_Front) against the ["People's Front of Judea"](https://en.wikipedia.org/wiki/Eritrean_People%27s_Liberation_Front). The joke is so wonderful and sad because it hits exactly the spot; people are often more hostile to potential allies instead of the real ideological enemy.
] |
[Question]
[
Could primitive human like species evolve into highly advanced race only using bio materials (other than wood) during their advancement (instead of other tools as early humans developed from iron, stone and other non-organic sources)
If so what would be the key inventions during the earlier stages (like the wheel, fire, etc. during our present path of technological development) and will this technology be eco-friendly or harm the environment?
**Note**
Here, biomaterials may include any material of direct organic source. This question is not about technology without metal but metal derived from organic sources may be utilised indirectly.
[Answer]
Well now. This question is interesting.
The answer is: yes, but you're going to have to redefine your concept of 'technological' and also accept an awful lot of conjecture to get it to work.
Consider the following:
A tribe of proto-humans (let's just call them Monkeys for short) are living on a beach. They're scavengers, but not all that bright.
One day the Monkeys come across a beached whale carcass. They tear happily into the eyes and lips, but the thick blubbery skin prevents the majority of the tribe from getting to the tasty blubber.
Now, Joe is an atypical Monkey. He's scrawny, but inquisitive and pretty smart. Having been pushed away from the tasty face of the whale with only a few scraps of flesh he stumbles across a tidal rock pool. In the pool wallows a Proto-lobster. It's hungry, simple and running out of time to live. Joe, intrigued, lopes over to the weird insect fish thing, and following some weird quirk of his Monkey brain offers some food to the evidently struggling proto lobster.
The protolobster's legs aren't strong enough for full terrestrial movement, but it's a tidal creature and hence amphibious, and when the hairy brown arm of God descends from on high proffering tasty whale, the lobster scuttles up, keeping it's jaws locked on the food, and latches onto the furry surface.
Joe is initially shocked by this, but when he heads back to the tribe to show them his discovery the lobster, not relinquishing it's grip on his arm, snaps out at the exposed flesh of the whale. The lobster has sharp claws, and as Also Spake Zarathustra plays in the background Joe lifts his new Arm-Lobster on high.
Now, who would think to pick up a rock when you have a suitably trained and specially bred arm lobster? From this point the development of the Monkeys becomes a bit nebulous and can basically be defined however you like, but it essentially replaces technological development with advances in selective breeding, animal husbandry and training techniques. Development would be much slower, but after a while the concept of hefting a rock would be as alien to the Monkeys as strapping a lobster to your arm to act as a trainable Swiss Army knife/extra set of hands is to us.
This brings me by a roundabout route to the meat of my point. If this is a thing that happens it will have to happen so far back in evolutionary history that it's impossible to say whether it would or would not have worked. 'Technology' becomes a matter of increasing levels of symbiosis rather than increasing levels of refinement, and the world would be utterly different in physical, social and even moral perspectives.
On the other hand, Pimp My Lobster would be a hit on the Cuttlevision.
[Answer]
I tried. I really did. Three paragraphs in, I had no choice but to turn this into a reality check. Do bear in mind, I gave this enough consideration that *I reopened this*.
So. There is no way, on any Earth like planet, that primitive creatures don't learn to hit stuff with rocks before they learn anything else. I mean, sea-gulls know this trick, dude.
The problem is this - lets say there are plenty of small, armored critters with chitin hard enough to woodwork, or whittle bone. Let's say there are enough of them that no one ever considers finding or using flint, because the pincers on these critters are that plentiful, and that effective. You now have the serious issue on your hand of dealing with wildly sharp, armored land bugs that only probably aren't very cuddly. Primitive bipeds aren't going to sit around and wait for these things to die - they're going to beat them down with rocks and scoop out the delicious insides.
So you might be able to replace early flint tools with bug arms, from which they can start early woodwork and scrimshaw tools. These tools are soft, and leave you unable to cut anything harder than bug arm, so you have a problem - either bug arm is as hard as bronze, in which case humanity is *totally hosed*, or you have to write in a biological source of something *even harder* than bug arm, in which case *humanity never evolved*. Our brilliant tool making minds find ways to do things, but there isn't a way to make Mohs hardness not a thing - we survived because *we were built better than our competition*. This will not be true against a race of critters with metallic scale armor.
If you take it to a certain point, and then do some future history, it makes more sense. Here, on Earth, right now, there are several processes we use organic bioreactors for. One that springs to mind is ethanol production, and we're trying to develop more.
Note of course that there is a huge difference between organic and eco-friendly. Lots of organic chemistry is pretty bad stuff.
[Answer]
A long story short: without metal we couldn't evolve a thing like 'biotechnology'. It would be like stone-age with us running around wrapped in smelly fur and waving flintstone-axes.
I don't see a way how metal could be derived from organic sources without complex machines. And to build those machines you'd need... non-bio materials.
Ad the invention of the wheel and of fire: as far as I know they where made with sticks and stone. So you'd have both in your biomaterial-world too -allthough stone is non-organic ;)
] |
[Question]
[
A recent question concerning generation ships made me come up with a rather original alternative [in my answer](https://worldbuilding.stackexchange.com/questions/11735/how-to-make-humans-not-negatively-affected-by-radiation/11744#11744). It was pointed out that the concept of [embryo space colonization](https://en.wikipedia.org/wiki/Embryo_space_colonization) has already been thought of thoroughly although personally I never heard of anything alike despite being just as plausible as other ideas.
My question is not specifically aimed at the two aforementioned concepts – nor their perceived (in)popularity – but about colonization in general:
Considering the prospective technological advancement:
>
> What way to go about **interstellar colonization** is likely to be the **first** one **technically and monetarily feasible**?
>
>
>
To get this going here a short list of approaches that will get updated as you suggest concepts that have not been mentioned.
**Please note:**
* A basic premise is humans will be still humans, i.e. concepts akin [mind uploading](https://en.wikipedia.org/wiki/Mind_uploading) to (humanoid) robots are not within the scope of this question.
* You might combine or modify known concepts.
## Travel-oriented
### Decreasing travel time
* traversable [wormholes](http://en.wikipedia.org/wiki/Wormhole)
* [Alcubierre drive](http://en.wikipedia.org/wiki/Alcubierre_drive)
* other faster than light traveling
### Decreasing travel discomfort
* [generation ships](http://en.wikipedia.org/wiki/Generation_ship)
* moving the planet
* [suspended animation](https://en.wikipedia.org/wiki/Suspended_animation) during flight
## Other
* [embryo space colonization](https://en.wikipedia.org/wiki/Embryo_space_colonization)
[Answer]
I would like to modify the answer provided by @ArtOfCode - While we can presently freeze bodies, the re-animation process is still not fully possible, and even if/when it becomes feasible, it will be quite some time until we'll be able to send a ship into space for a 10,000 year journey that they'll be able to reliably wake up from.
It is far easier to freeze embryos and keep them viable for a long period of time. It's actually in the realm of current commercially available technology (albeit at a relatively smaller scale and for shorter spans of time). We have also been working extensively on building cellular scaffolds for the purposes of observing cells in an *in vivo* environment.
My proposed addendum is as follows:
1. Ship suspended animation gametes rather than any currently living humans. DARPA can already place rats in temporary stasis, so single cells should be easy.
2. Upon landing on planet and setting up shop, use a robotic 3-d printer to craft scaffoldings for a roboticized human uterus. Since we can directly control design factors, we can easily eliminate any issues surrounding the birthing canal and general integrity of the womb.
3. Combine the gametes together to get *in vitro* oocytes.
4. Seed the robo-uteruses with stem cells cultivated from your oocytes.
5. Feed the uteri with blood produced by stem cells cultivated into blood producing marrow.
6. Keep the cells alive during growth with a nutrient chemical bath.
7. Now you have a functioning human womb ready to accept a viable embryo!
8. I guess, lastly, have some sort of caretaking robot that can help ensure the newly born, parentless humans don't perish until they can start learning to take care of themselves. Also, they need to be taught language and learn to read wikipedia. Caretaking robots for the elderly are already in limited existence. This is an extension and expansion of that same concept.
Almost all of these are things we can ALREADY DO with present technology at a decent cost!
The only major concerns are space radiation, machine reliability, and the morals/ethics of seeding a planet this way, I guess. You don't have to worry at all about maintaining a sealed, breathable atmosphere or avoiding high G forces that would kill a multicellular organism.
All in all, this would be the simplest, most immediate way (from our end) we could seed a planet outside the solar system with life.
[Answer]
While uploading human personalities to robots is out of the question, giving robots robot personalities, capabilities and intelligence is not. So:
## **Robotically Controlled Suspended Animation**
This method, which I shall term RCSA, makes use of robots (who have no concept of time apart from milliseconds since some date or other) to control a colonising fleet.
1. **On Earth**
This method is very similar to just using great big generation ships. You build the fleet first. You then install the cryogenic SA modules. At the same time, you should be building a load of robot crew for each ship.
You give these robots advanced AI that is capable of moving a ship around space and responding to scenarios. You throw them in a simulator for thousands of hours each to iron out every possible problem.
2. **Launch**
Once the ships and crews are ready, you load the colonisers. Each to his own cryo unit. (You could also freeze embryos or human gametes - there is another answer here detailing this). Activate the cryo units, launch off into space and get going.
3. **In Spaaaace**
Since you've done all the simulations with the AI, they'll handle all the space travel, navigation, and calculation necessary to get you to the target planet. You did remember Sim 62A/4D "Extraterrestrial Contact", didn't you?
Note 1: now is not the best time to discover you should have given the AIs access to an emergency "wake people up" button.
4. **Landing**
Since you thought of everything and have given the ships enough heat shielding and retro-rockets to safely enter an atmosphere, this is still an easy part: you can still rely on the AIs. Now, press the wake-up button, and let your humans loose on their new home.
---
Please note: RCSA does not deal with terraforming or infrastructure setup on the target planet. However, I imagine you could also fly a supply ship over and some other skilled robots to help.
Colonisation Systems, Inc. does not accept liability for any lack of simulation or consideration of required emergency features by You. The simulation list We provide may not be exhaustive.
] |
[Question]
[
On Earth, the planet itself is negatively charged and the clouds are positively charged, causing lightning to travel from the clouds to the surface. While there are significantly smaller wisps of lightning that reach from the Earth to the clouds and the bolt that is travelling down, would it be possible to have a planet in which the charges are reversed, causing lightning that arcs from the planet to the clouds?
If possible, how would this different charge affect an Earth like planet?
[Answer]
**TL;DR: Lightning in our world can possibly do both, so there probably wouldn't be much of a change.**
Lightning is a form of static discharge caused when an excess of electrons exist in one location (e.g. the ground) and a lack of them (e.g. in the clouds). This would result in, if enough potential energy (voltage) existed in the electrons, a discharge in the form of lightning from the negative to the positive.
In the scenario you give, what we actually would have is lightning going from the negatively charged planet to the positively charged clouds! As far as I understand it, lightning going from ground-to-cloud or cloud-to-ground are both entirely possible on Earth, it just depends on how the charges are split. It's also why clouds often have lightning strikes between them (distances are shorter, potential energy required for an ark is less, hence *ZAP*). HOWEVER, the typical strike is in fact due to "feelers" of negative charges extending downward from the clouds. The bottom of a storm cloud is typically negatively charged, and the ground is typically positively charged below it.
To answer your question, both would be possible, thus I do not see why you couldn't have the convention between them change. If you're building a world, a little hand-waving can get around most physics things (ooo, magic), especially when science itself doesn't understand the phenomenon 100%.
Some additional reading:
<http://en.wikipedia.org/wiki/Lightning>
<https://www.ec.gc.ca/foudre-lightning/default.asp?lang=En&n=9353715C-1>
<https://earthscience.stackexchange.com/questions/580/why-does-lightning-strike-from-the-ground-up>
[Answer]
Lightening is a discharge to balance the electrical charge that has built up between objects, (the earth and clouds, or between clouds etc.) Lightening can travel in either direction already here on Earth. The ground is not 'positive' and the sky is not 'negative'. Regions get an imbalance and the ground could have the negative charge or to put it more correctly the sky could have a more positive charge and thus attract a lightening strike from below.
] |
[Question]
[
## *A la* this image I made.
The "how" ([nuclear pulse drive](https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)) "adjusting" Eros's orbit at its aphelion) and "why" (uber-sized [Rods from God](https://www.google.com/search?q=rods+from+god&oq=rods+from+god&aqs=chrome..69i57.1231j0j1&sourceid=chrome&ie=UTF-8)) isn't particularly relevant — all that's relevant is that [433 Eros](https://en.wikipedia.org/wiki/433_Eros)'s perihelion has been changed from 1.1334 AU to 1 AU, and its orbit just happens to intersect with the Moon at that perihelion. Oh, and none of this is to scale, but the angles in it (especially the first image) are intended to be accurate.
[](https://i.stack.imgur.com/m7qXa.png)
Anyway, in order to calculate the presumably-unfortunate effects of this on the Earth, I've done some math (see the bottom of this post). However, as I can't find hard data which would let me make fairly accurate guesses, I'm currently making the following assumptions:
* 10% of the energy released by the impact is converted into [ejecta](https://en.wikipedia.org/wiki/433_Eros) velocity; the remaining 90% is absorbed by the Moon.
* 10% of the ejecta energy is in ejecta that escapes the Moon at 2,380 m/s or more; the remaining 90% falls back into the Moon. The Moon's escape velocity of 2,380 m/s provides a benchmark for determining the mass escaping the Moon; 10% of the energy dumped into flinging rocks out of the Moon will fling them fast enough to escape the Moon's gravity. All the rocks flung by that 1% of the impact energy will be going ≥ 2,380 m/s, letting me determine the maximum mass escaping the Moon.
* 25% of the ejecta escaping the Moon falls into the Earth over time, and 25% of it will fall into the Moon over time, with the remainder coming back under the gravitational influence of the Moon. This relies on the next assumption...
* ...that Eros hitting the Moon tail-on at a right angle relative to its surface means none of its fairly impressive velocity will carry over into propelling ejecta, meaning none of the ejecta the impact produces will be going quickly enough to escape the Moon/Earth system entirely. Sure, there's [Newton's Third Law](https://www.physicsclassroom.com/class/newtlaws/Lesson-4/Newton-s-Third-Law), but much of the "equal and opposite" reaction to Eros's impact/disintegration will go into crushing/compressing lunar rock, not throwing it away from the Moon. Also, crushed rock can be crushed further or pushed out of the way to crush more rock, whereas rock that's been thrown away can't have any more energy dumped into it.
* Of the 50% of the ejecta that escapes the Moon, ends up under its gravitational influence again, but does not directly fall into it, the Moon will act as a [shepard moon](https://en.wikipedia.org/wiki/Shepherd_moon) towards it, [slingshot](https://en.wikipedia.org/wiki/Gravity_assist) half of it (the ejecta orbiting slightly inside the Moon's orbital path) out of the Earth/Moon system, and slingshot the other half of it (the ejecta orbiting slightly outside the Moon's orbital path) into the Earth.
* 10% of the ejecta pulled into the Earth actually makes it through the atmosphere to impact; the rest is too small to make it to the surface and disintegrates in the atmosphere.
Basically, if we look at the image below (which I got from the 9th page of [this](https://www.lpi.usra.edu/books/AsteroidsIII/pdf/3033.pdf)), assume the asteroid represents the Moon, and assume the arrow represents the trajectory of a piece of ejecta...
[](https://i.stack.imgur.com/Txiyl.png)
* 90% of the impact's energy is in that little explosion and doesn't go anywhere.
* 9% (90% of 10%) of the impact's energy propels Class I ejecta.
* 0.25% (25% of 10% of 10%) of the impact's energy propels Class II ejecta.
* 0.25% (25% of 10% of 10%) of the impact's energy propels Class IV ejecta that gets slingshotted out of the Earth/Moon system.
* 0.25% (25% of 10% of 10%) of the impact's energy propels Class IV ejecta that gets slingshotted into the Earth.
* 0.25% (25% of 10% of 10%) of the impact's energy propels Class V ejecta that reaches the Earth directly.
* In regards to the Moon, Class III doesn't exist; any ejecta that ends up in Class III will, over time, get pulled out of orbit and crashed into the Moon by [lunar mascons](https://en.wikipedia.org/wiki/Mass_concentration_(astronomy)#Lunar_and_Martian_mascons), essentially putting it in Class II.
Or, for another visual, this image:
[](https://i.stack.imgur.com/NKXI4.png)
* This is a "top-down"/"birds-eye" view of the Earth/Moon system; the Moon's orbit takes it towards the bottom of the page, and the entire thing is moving to the left as it orbits the Sun.
* If ejecta is in the blue section, it's orbiting faster and at a lower altitude than the Moon, so it'll either fall into the Earth or "outrun" the Moon over time, eventually catch up to it again, and then slingshotted around the "bottom" of the Moon and out of the Earth/Moon system.
* If ejecta is in the red section, it's orbiting slower and at a greater altitude than the Moon, so the Moon will "outrun it" over time, meaning the ejecta will either fall into the Earth or have the Moon eventually catch up to it again, slingshotting it around the "top" of the Moon and into the Earth.
* If ejecta is in the green section, it's not going fast enough to escape the Moon's gravity, so it'll fall back into the Moon.
Yet another image, from the same perspective:
[](https://i.stack.imgur.com/1jBWX.png)
The Moon acts as a shepard moon; any particle orbiting to the left of or behind the Moon in the same direction gets thrown into the purple outer ring, whereas any particle orbiting to the right of or in front of the Moon in the same direction gets thrown into the orange inner ring, and likely within the Earth's [Roche limit](https://en.wikipedia.org/wiki/Roche_limit) for particles of that size, meaning tidal forces will eventually tug the particle into the Earth.
## Why am I asking this question?
Simple: **I need to make better assumptions.** Remember all those percentages? I need to know whether, for instance, assuming the Moon will absorb 90% of the impact energy is accurate or not, or whether or not the Earth will actually be hit with half of what escapes from the Moon.
To reiterate — I'm currently assuming that:
* 10% of the energy released by the impact is converted into ejecta velocity
* 10% of the ejecta energy is in ejecta that escapes the Moon
* 50% of the ejecta escaping the Moon hits the Earth
* 90% of the ejecta hitting the Earth burns up and becomes airborne particulates; the remaining 10% physically hits the Earth's surface
**Are these accurate assumptions to make in regards to modeling an impact between the Moon and 433 Eros?**
## Anyway, here's that math I mentioned:
```
6.687 quadrillion kg 433 Eros impact w/Moon @ 1 AU from Sun, prograde Moon velocity
```
>
> * 34,148 m/s velocity relative to Sun - 1,022 m/s Moon orbital velocity = **33,126 m/s** collision.
> * (((33,126 m/s)^2) x 6.687 x (10^15) kg)/2 = **3.66892913 x (10^24) J** impact energy, **3.66892913 x (10^23) J** net ejecta energy, and **3.66892913 x (10^22) J** of energy in the ejecta escaping the Moon.
> * ((((3.66892913 x (10^22) J) x 2) / ((2380 m/s)^2)) = **1.29543434 x (10^16) kg** total ejecta escaping the Moon, of which...
> * ...**3.2385859 x (10^15) kg** falls back into the Moon, **3.2385859 x (10^15) kg** is flung out of the Earth/Moon system by the Moon, **3.2385859 x (10^15) kg** is flung into the Earth by the Moon, and 3.2385859 x (10^15) kg falls directly to the Earth by itself.
> * Of the **6.4771718 x (10^15) kg** of ejecta hitting the Earth, **5.8294546 x (10^15) kg** burns up into atmospheric dust and **6.4771718 x (10^14) kg** physically impacts the Earth's surface.
>
>
>
It would be a lot worse if Eros hit the Moon head-on as the Earth was coming around the Sun at a right angle to its trajectory. Conversely, it'd be a lot less dangerous if it came in in the same direction Earth was orbiting in. As a compromise, I had Eros broadside the Earth/Moon system halfway between those two extremes.
Also, note that these calculations don't include the velocity incurred by Eros accelerating as the Moon's gravity pulls on it, nor the velocity incurred by the nuclear pulse drive attached to it firing off its last H-bombs to add some extra [ΔV](https://en.wikipedia.org/wiki/Delta_(letter)) right before impact for maximum energy release. They're also fairly inaccurate in that they try to divide the types of ejecta trajectories into a few neat little categories rather than the mess that [*n*≥3](https://en.wikipedia.org/wiki/Three-body_problem) orbital physics usually are, as well as because they portray 2,380 m/s as the velocity of all the ejecta escaping the Moon (some would go that speed, much would go faster, meaning that 1.29543434 x (10^16) kg is probably too much). However, these are the bare minimum; I'm basically going for a [Fermi estimate](https://en.wikipedia.org/wiki/Fermi_problem) here.
[Answer]
Well, let me attempt to give a few clues to what the right answer might be. However, before let me stress;
**Just do what is good for the story. In this case you have a situation where any outcome is reasonable. From a World Ending event to Virtually no debris. The entire range is within reason.**
*It depends*
On a lot of factors. The two biggest of which are the angle of incidence and impact velocity. These two factors will contribute the most to your question.
First, the Velocity. Using Universe Sandbox 2 (So a Newtonian Simulator that will have inaccuracies), the 1AU Velocity of Eros should be **33800 m/s**. Now, Earth's velocity is **29600 m/s** and Lunar orbits between **1080 and 970 m/s**. Now the big question is what the *relative velocity* will be. For the biggest effect we can assume that Eros slams into Lunar, so Lunar moves towards Eros at 1080m/s. This means Lunar and Earth's velocity add up (since by definition Luna is at its lowest point in the orbit. So, the Impact velocity of Eros is **33800m/s - (29600m/s - 1080m/s) = 5280m/s**. Or 4200 if the orbit is the other way around, but again we assume the most energetic impact possible.
Now, the Angle of incidence will have to be equal to the tilt of Eros´s orbit. Which is 10.8 Degrees. Which for us translates to 90-10.8 = 79.2 Degrees. When you run the numbers of such an impact at the equator it looks kinda like this;
[](https://i.stack.imgur.com/jmEDs.png)
All of the red lines show you where the debris are going. As you can see a grand total of 0 come back to the Moon, which is because this image assumes an equal velocity for all of them, which is of course not true.
But that is not to important, for now anyways, the important part is that all of these Debris are moving at about 4000-5000 m/s. Which means all of them are faster than escape velocity at Lunar orbit. Which intern means the supermajority of ejecta is bound to leave the Earth Lunar System. Now, these Debris are move Retrograde relative to the sun. So they are moving at about 25km/s. So the debris are all in an orbit around sun and will come back about 8.55 months later.
So, my conclusion would be that Initially not a lot of ejecta would hit Earth. The impact is extremely violent which in this case kinda works in favor for us. At least initially. The issue is that all of this ejecta is still there. And every 8.55 months it will reach Earths orbit. So we can expect a Shower of this ejecta every few years. How many Years ? My sim´s say the first intersect happens about 10 years later. However in reality the Ejecta will form a ring on this orbit so with each year passing impacts will become more and more frequent.
In saying that, other gravitational bodies still exist so it is likely a lot of the large pieces would get thrown out.
] |
[Question]
[
Someone has stopped all time. Dont worry, some people realized someone was tampering with time and they managed to create bubbles of time where they live, trying to build more equipment that lets them expand the bubbles they are in and build new bubbles where they need it.
Ofcourse you need your own light inside that bubble, as light outside the bubble wont be reaching your eye. You also need your own power source for creating oxygen, recycling waste etc. Fortunately you figured out a way to turn individual molecules of matter into useable energy by making it think its an evaporating black hole, so power isnt going to be an issue any time soon. Fortunately gravity doesnt seem affected by time so you wont be flying off into the time barrier surrounding your tiny bubble of time.
But then I started thinking of the border of the bubble, what would it really do to any matter there?
Lets put up some restrictions:
* the edge of the bubble no thickness but it does have a "grace period" where the particles slow down until they are too frozen in time (which takes on average 0.001 seconds if you need it). During this grace period it lends time to any matter it would normally interact with letting it push it out of the way or heat it up. However the ONLY interaction will be with particle on their grace period, any interactions the outside particle had before would not resume until full time re-asserts itself (to prevent one particle from displacing an entire atmosphere because it pushed one particle).
* the matter outside the bubble can be assumed a normal earth atmosphere and ground.
So the question is, what would happen at the edge and how to describe it? (Or if this completely fails, do I need to alter the parameters of the bubble to make sure it remains liveable inside for extended periods of time).
Keep in mind the following:
* all radiation such as light ends up across the border at some point.
* the very air is constantly moving in all directions and constantly collides with the barrier.
* matter that is stuck on the other side has no time to interact with the matter inside the bubble other than when grace-period matter interacts with it.
I would hazard a guess that at some point there would be so much matter at the edge that matter inside the bubble would simply bounce off, preserving the bubble.
[Answer]
**Solid wand**
Your bubble will need a solid wand. That would allow a separation of the tempo of time inside and outside of your bubble, in separate worlds. There's light inside, light outside.
**But.. why would a bubble of matter grow by itself ?**
You seem to assume the wand attracts matter by itself. But what brings matter significantly closer to the edge of the bubble? Why would air or matter accumulate at the time boundary ? Brownian movement won't be affected by a time discontinuity existing elsewhere. Light and radiation may "end" on the wand but they do not consist of matter.
**Pitfalls of the boundary**
A space time discontinuity seems dangerous to me: particles at the boundary could gain near light speed momentum, go oscillate between the two realms and warm up the wand, to e.g. 10e21 degrees or so. Not really convenient. Also take into account photons can loose energy ("ends" as you state) but they could also gain energy, at the boundary, when seen from the other side. Maybe not the kind of light you want to look into..
**Two metal spheres separated by a vacuum**
Isolate it. You need a construction. It may be more practical to have this time discontinuity exist inside a vacuum, inside the wand.
*Proposal:* your bubble consists of two separate spheres of rigid material e.g. metal, with a vacuum in between. The time boundary exists in that vacuum and the [Casimir effect](https://en.wikipedia.org/wiki/Casimir_effect) prevents the spheres from colliding.
[Answer]
**Air Leaves the Bubble**
The air molecules are vibrating back and forth chaotically. Molecules near the border will randomly move towards it and get stuck there and get frozen in time. Since they can leave but not return this leads to the amount of air in the bubble decreasing until it becomes a vacuum.
Depending on how the rule for molecules moving to make room for each other, you might get a dense shell of frozen-in-time air just beyond the border. However this shell is no barrier to new molecules leaving the bubble.
] |
[Question]
[
I'm writing a tale about a possible far future scenario for humanity. Well, not quite the entire humanity. Every part of the story is ultimately connected as it's viewed through the eyes of the members of the same family line and their daily lives so it's a pretty limited perspective based story. Nonetheless, it has 7 different parts to it, the OG character, then 5 generations, 20 generations, 100 generations, 300 generations, 600 generations, and finally 1000 generations in the future. Now to the main point of the question: The connection between them lies in that there is one object that follows them through the entire journey, sort of like an ancient valuable possession of a family tradition.
It starts here and now with the OG character, a regular dude living in a first world country in the early 21st century AD. One day he gets a brilliant idea of sending a time capsule to his descendant one thousand generations down the line. However, after thinking more thorougly about it, he's hit with a barrage of practical problems to solve before he can carry out the plan. The first one is that 1000 generations is an insanely long time. If a generation lasts somewhere between 20 to 30 years, we're talking about 20,000 to 30,000 years into the future. He's going to be almost as ancient to the recipient as the Neanderthals were to him. Even the oldest scriptures literally carved in stone are no more than 200 generations old. There's going to be a lot of printed out photos of his life, as well as a letter, a diary, and a few random everyday objects and tools. Not that the recipient could read the letter and diary due to language evolution but who cares, they're still gonna find it interesting AF. They're going to be sealed in separate bags, then put inside a few layers of boxes then wrapped in plastic. What kind of material should the boxes and bags be made out of in order to ensure they last 30k years, and are the content likely to survive all that time intact instead broken down into dust? For context, the box would not be exposed to the elements and is barely touched by anyone so i wonder how long it can last then.
Lastly, there's going to be a lot of rules and measures to pass down in order to ensure it survives and gets delivered all the way through. But what? What are some good measures to increase the likelihood of having a thousandth descendant at all? And how likely is it to work anyway?
[Answer]
# Boxes and Bags Won't Cut It
You might want to look into the [Long Now Foundation](https://longnow.org/) - their aspirations are ten thousand years, less than half your goal, and they consider conveying any message that temporal distance an undertaking that will require decades of effort.
Most consumer plastics, left to their own devices, begin to depolymerize after a few decades even with no exposure to the elements. Even in a dry environment, archival paper is only rated for a few hundred years. I can't speak to the "tools", but it would depend on what they're made of and what they're exposed to.
You could definitely extend the lifespan of many of the items by sealing them in a vacuum or atmosphere of inert gas, but
1. You'd need to make sure that at each interval, there was a mechanism to re-seal them in that environment and the user knew what to do, and
2. You'd need something that could *maintain* a sealed environment for twenty thousand years, which is generally the kind of thing that involves *burial inside a mountain*.
This is all aside from the fact that, as commenters have pointed out, after a thousand generations, your descendants are either everyone or no one.
*Edit: Additional Examples*
* [The Westinghouse Time Capsules](https://en.wikipedia.org/wiki/Westinghouse_Time_Capsules) - thick corrosion-resistant metal encapsulating glass in which the items were sealed in a nitrogen/argon atmosphere. Only intended for 5000 years, though, and expected to be underwater by that point.
* [KEO](https://en.wikipedia.org/wiki/KEO) - a space probe intended to be launched to return to Earth fifty thousand years later, containing specially-manufactured DVDs and material samples stored inside a multilayered, cosmic-ray-resistant shell. Still doubtful it'll last (if it's ever launched), but definitely the most likely avenue to having something last a thousand generations.
[Answer]
# Museum Specimen Preservation
According to my local nature and science museum, there are several things which can destroy a sample:
* Light
* Temperature
* Relative humidity
* Physical Forces (mishandling)
* Fire Damage
* Water Damage
* Pest Damage
* Pollutants
* Neglect and Disassociation
* Theft and Vandalism
# Longer Timescales
Over longer timescales, though, you would also have to worry about the physical structure of your message degrading. Bits on computer drives will not last, as they will demagnetize. Archival paper will go longer, but will ultimately succumb to other forces.
The only thing that stands a chance is to get a really hard, very stable material, like... [Quartzite](https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.columbia.edu/%7Evjd1/weathering.htm&ved=2ahUKEwiM0K_Oipf6AhUqAjQIHcjdCl4QFnoECCQQAQ&usg=AOvVaw2m1UJwqShcdZNwZMBBzT4F)! It apparently can withstand a lot of mechanical and chemical weathering.
So the capsule and/or its contents should be made of quartzite. This takes care of a lot of the issues noted above! The choice of material here negates a lot of items from the above list. (What rodent is going to want to chew a rock, after all?)
# Renewal is Better Than Maintenance
This is going to be tricky but also the best bet for getting individuals down the line to receive the information. Whatever is in there has got to be worth the effort! Like... A family history written in stone! Descendants and maintainers can add to this and it quickly becomes a *history of the human race.*
That's a universal enough reason to keep this recorded and maintained. Yes, the original content is possibly drowned out, but asking "[what's the first thing written in this history](https://en.m.wikipedia.org/wiki/Kish_tablet)?" is likely to never go out of style! Additionally, of something does break, there will be people there to make a new copy. This then takes care of the final items on the museum specimen preservation list.
] |
[Question]
[
I am currently working on a world orbiting around a red dwarf star (M0V to M2V, I haven't decided yet) and I need some help with designing the solar system. My original plan was having 4 planets orbiting the star:
* 1st planet: a small rocky planet the size of Mars, very close to the star, a lot of volcanic activity, thick atmosphere (basically a smaller Venus)
* 2nd planet: an Earth-like planet with a surface gravity of 1.5 g. Habitable, orbits in the star's goldilocks zone, has a composition of elements similar to Earth (rich in metals and minerals, Earth-like atmosphere, liquid water) tidally locked
* 3rd planet: a gas giant about the size of Saturn with 5 named moons (I say named because only 5 of them are big enough to be spherical, there are several other moons that resemble meteorites)
* 4th planet: an ice giant similar in size and chemical composition as Uranus with 3 named moons
* Asteroid belt: a collection of asteroids and other dwarf planets at the outskirts of the solar system
From what I understand planets form from the debris disk that surrounds the star at the start of their life cycle. But red dwarfs are considered to be the smallest and dimmest of stars. Would their debris disk have the amount of elements required for the formation of these planets?
[Answer]
**Believable**
Red dwarf stars have mass of about [0.08-0.45 solar masses](https://nineplanets.org/red-dwarf-star/). But one solar mass [is about 333,000X the mass of Earth](https://en.wikipedia.org/wiki/Solar_mass). Even at their smallest average, a red dwarf is 26,600X the mass of Earth. it seems beyond believable that there could be enough mass in the star's debris field to create planets.
Even [Jupiter is just 0.001 solar masses](https://www.unitsconverters.com/en/Jupitermass-To-Solarmass/Unittounit-6003-5994) or 1/80th the mass of the **smallest** red dwarf.
**Wait... you didn't use the word "plausible."**
I'm not a fan of "plausible" or "realistic." The universe is constantly showing us wonders that "just last year" we didn't think were possible. Besides, who's the audience for your efforts? PhD Astronomers? That's why I prefer the word "believable." Even if our current knowledge base about red dwarf stars suggests none have planets, the basic statistics say there *could* be planets. And all that means is we need more time to find the so-called exception that breaks the rule.
So, the only real issue here is just how big is you red dwarf? The larger it is, the more believable your solar system becomes.
[Answer]
The answer is: your setup is definitely plausible.
I have a personal story about this question. Back in 2007 I wrote a scientific paper (I'm an astrophysicist) arguing that very low-mass stars might not have enough material to form Earth-mass planets, as you speculate. (Link to paper [here](https://arxiv.org/abs/0707.1711)).
Well, turns out that I was wrong: there are lots and lots of Earth-sized or larger planets around even the smallest stars. There's actually more (by number and total mass) than around Sun-like stars! The most extreme example is the Trappist-1 system, with seven roughly Earth-sized planets around a super-puny star. (The main reason for this, we think, is that a lot of stuff migrates inward close to the star, providing plenty of material from which to build planets, even around small stars -- see [here](https://planetplanet.net/2017/04/18/breaking-the-chains/) for a description of our model for how they form).
This image shows some of the exoplanet candidates in the habitable zone, and you can see that there are plenty around small red stars.
The only part of your story that is less likely is the asteroid belt. Given how close they orbit to their host stars, collisions are generally more energetic around small stars and belts of asteroids grind down and become pretty puny (like our own) really fast. So your system could have an asteroid belt, but it should be pretty depleted.
Does this all make sense?
[](https://i.stack.imgur.com/rrEc1.jpg)
] |
[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.
How fast could a human-powered medieval projectile go?
Rules:
* The weapon must be made of materials available in medieval times: wood, steel, catgut, bone, rope, etc. No modern composites or plastics.
* Engineering must be done to tolerances achievable in medieval times.
* Human muscle power must be the power source. No explosives, no fires, no battery piles.
* Electricity-powered weapons like railguns or coilguns are not allowed. Magnets are not allowed.
* It is allowed to store the human muscle power as elastic potential energy (e.g. a bow), kinetic energy (e.g. a flywheel), gravitational potential energy (e.g. a trebuchet), compressed air, or thermal storage. Other energy storage methods are not allowed.
* If necessary, it is allowed to have many humans working together to power the weapon.
* The design of weapon does not need to have been known to medieval engineers, as long as it uses medieval materials in conformance with these rules.
* Speed of projectile is measured at time of release.
So, what are the upper limits for projectile speed? Can we get to 800 m/s, like a sniper bullet?
[Answer]
Empirical evidence: the whip.
The crack of the whip happens when the whip tip reaches the speed of sound in air (about 330-340 m/s depending on air temperature). Massaging [the equations](https://www.math.arizona.edu/%7Eura-reports/031/Taft.Jefferson/Report.pdf) seems to indicate that up to three times that is possible without needing special materials (crude springs have been available for a long time).
This means that a projectile speed of 1000 m/s is **possible** (or should I say, *not impossible*).
On the other hand, actually *achieving* this speed requires either luck, or *knowledge* or *research* - the means to investigate whether the speed is going up or down with different setups, and even the awareness that a higher speed is *possible* at all.
None of these things, except luck, were available in the Middle Ages.
The speed of such a projectile, detaching from the whip exactly at the time of the crack, would also probably rapidly fall off due to aerodynamic considerations (adding fins to it seems excessive. Again, it is *not impossible*).
Also, nothing has been said about *aiming* the projectile.
] |
[Question]
[
Is there a plausible explanation for some sort of theoretical technology that manipulates the character's primary motor cortex into being ambidextrous?
For example, a character loses their right arm and cannot replace it with a robot one. But they're in a position where they don't have enough time to learn to switch dominant hands the old-fashioned way.
Would it be scientifically possible for some sort of nanotechnology to either manipulate their brain or their hand into "thinking" the character has always been left-handed so they can continue to work? I'm not completely sure how much of right/left-handedness is controlled by the mind and how much is muscle memory.
I realize there's a level of handwavium to this (and most other technorganics in science-fiction), but anything believably science-based would be appreciated.
[Answer]
**It's all in the brain - mostly**
"[Muscle memory](https://en.wikipedia.org/wiki/Muscle_memory#Muscle_memory_encoding)" is used to refer to the *brain's* programming of repeated use of particular actions. Which means that if both limbs are fully symmetrical and equally muscled, then "all" that is required to use the non-master limb equally well is the ability for the brain to translate the outgoing signals so they can be sent to the other limb.
However, there are a few possible issues with this, depending on the skill that is in use. For example:
1. Master eye - all people have a dominant eye when shooting, aiming etc. When instructing with firearms, bows etc the first step is to determine the dominant eye, then train the shooter to use the hand that allows that eye to be used for aiming. Unless you can re-wire the dominant eye at the same time, a person will not be as good at shooting with the other hand because of the eye rather than the limb.
2. Asymmetric equipment design - many firearms have some degree of asymmetry in their layout. For example, the majority of semi-automatic / automatic firearms eject their brass to the right, the safety catch on the F88 Austeyr is engaged when pushed fully to the right and disengaged when pushed fully to the left. (Yes, some handguns do have fully ambidextrous safeties and magazine releases but their is still some asymmetry.) Power tools also typically have asymmetric design - pushing a drill's selector all the way to one side makes the chuck spin clockwise, to the opposite side makes the chuck spin anticlockwise. This means that even when using equipment that can be effectively operated one-handed, actions do not translate exactly - using the F88 Austeyr example above, a movement of the thumb is required to apply the safety catch and a movement of the index finger is required to go to "Instant" when the right hand is on the pistol grip, whereas the opposite action is required when using the left hand.
3. Asymmetric activities - As mentioned in one of the comments on the question, handwriting is an asymmetric activity. Reversing it means that the person is writing in mirror image. If the brain was rewired to do the same for gross muscle movements as well as fine muscle movements then it would make the non-master limb unusable - if aiming at a target that moved to the right then the arm would move to the left! So any "rewiring" would need to ensure that it did not interfere with gross muscle movements.
4. Asymmetric muscle development. Back when I was fencing with sabres, my right arm/wrist/hand became much stronger than my left. The right limb was doing all the work during practice and bouts, while the left arm stayed locked behind my back out of harms way. (The left arm gets to move quite a bit move in foil and epee, sabre creates the most exaggerated asymmetric development.) Depending on the activity being undertaken it is possible that the muscles in the non-master hand will be less developed and that even if all the brain rewiring issues can be overcome that the user will be less capable due to inferior muscle development.
In summary - with sufficient skill at rewiring the brain, the non-master limb could be used effectively, but asymmetries in eyes, muscles, equipment and activity type may prevent equivalent competence from being instantly achieved.
] |
[Question]
[
Where could this be?
I'd like to have a small family (2 parents, 3-4 kids) living completely off-the-grid in some remote forest in the US. The story takes place in modern times. They have a well-established homestead. They farm, make their own food, and raise their own children, etc. They can access the outside world with some difficulty, but they are able to get things they can't make. Their homestead is secluded enough that it's plausible their children have never seen anyone outside their family. Indeed, that's the point.
I need the land to include a moving waterway like a river or large brook that flows year round.
Is there such a place in the US where there are forests but it doesn't freeze solid in winter? Hopefully rural enough that having a large plot of several miles would be possible? I considered the Pacific Northwest or upper Midwest, but it all seems too cold in the winter. An occasional frost or hard freeze would be ok.
[Answer]
**West Virginia**
* Mild winters
* Wooded
* Crenelated mountains that make thousands of tiny, remote valleys, short sight distances, and many small streams
* Limited highway access due to the mountainous terrain
* Strong heritage of independent living
[Answer]
**In a cave in West Virginia (or elsewhere in Appalachia)**
I've been to a number of natural caves in the Appalachian chain and I can't recall any that did not have flowing water to some extent. Some can have quite a bit as it's what created the cave in the first place. Cave systems of the Appalachians can be very complex and it's not hard to imagine some undiscovered or long-forgotten branch with large caverns near the surface hidden in some tucked away wooded valley. Maybe the entrance could be disguised as a shutdown mine to explain evidence of local traffic.
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.