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Requires answers backed up by equations, empirical evidence, scientific papers, other citations, etc. Contrast with: science-based and reality-check tags. This tag should never be the only tag on a question because this tag frames how a question should be answered, not the topic. Review the tag info ...

36
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3answers
7k views

Would EMP From a Nuke Stall a car?

In my story a man who works in Military Intel gets early warning that a nuclear attack on his base is inbound. He abandons his post, grabs his wife and kid from on base housing, and books it out of ...
6
votes
0answers
253 views

What would tides look like on a planet with two similarly sized and oppositely places moons?

I’m making a mostly ice planet with two moons. For the purposes of this question, let’s assume that they are both proportional size and distance to the size and distance to our moon. Both are tidally ...
12
votes
3answers
296 views

How far from the Sun could we detect an alien spacecraft similar to the Voyagers?

Suppose that there is an alien spacecraft travelling towards the Sun. This spacecraft is similar in design, size and power output to Voyager 1 and Voyager 2 as they were immediately after launch from ...
8
votes
2answers
229 views

Would it be possible to create an artificial iron star?

I ran a quick calculation, and the mass of iron required to form a black hole is on the order of 10^40kg. So, suppose that in my story there is this almost much iron available to somehow be brought ...
20
votes
1answer
1k views

Could a planet's Karman line hypothetically occur under a liquid surface?

The Karman Line is one of the most commonly-used definitions of the "edge of space". As an airplane flies higher in the atmosphere, the air gets thinner and thus the lift decreases. This can be ...
2
votes
2answers
224 views

How can I make this religion believing in “creating time traveling gods through science” believable?

I want to popularize the following or a similar belief. In many thousand years people will travel back in time to give us an afterlife, if we make it possible, by going the steps, that will lead to ...
4
votes
1answer
175 views

How to generate powerful cyclonic storms in an ocean basin

I have a region on a planet with identical parameters to Earth but different landmasses that is rather similar to the southern ocean on Earth. There is a single piece of land around the size of the ...
0
votes
0answers
70 views

If Earth's Moon Were Ganymede-Like, Part I: Rotation

I know that in the past I posted questions on if specific bodies larger than the moon--Mars in one and Titan in another--but this series deals with questions regarding Earth's effects by a natural ...
3
votes
1answer
68 views

Good approximative function to extrapolate weight of scaled clothing

Motivation The Square-Cube law is usually cited where questions of scale arise. Actually applying it to real-world objects quickly shows that it is completely unusable to approximate weight ...
1
vote
1answer
104 views

Big moon, small planet - can an earth sized moon orbit a moon sized planet?

I know that objects with lower mass tends to orbit objects with higher mass, is it possible to have a Moon sized planet who's mass is so heavy that an Earth sized planet orbit it as it's Moon in a ...
12
votes
1answer
206 views

How much electromagnetic transmission noise does Earth have to emit to be noticeable?

From time to time I'll see things talking about how thanks to all of our radio communications, we're effectively broadcasting our existence to the entire universe. However, when I did some back-of-the-...
1
vote
1answer
125 views

How do I create the largest possible space habitat for humans? [closed]

So I'm making a post-FTL world in which humans are the first, and so far only, species to explore the stars. It's thousands (if not millions) of years in the future, and we've become post scarcity. ...
6
votes
1answer
2k views

If Earth's Core had ALL Of the Heavy Metals

Back home, Earth had gone through an impact-coalesce cycle only once. Since then, its core has been 84% iron, 6% nickel and the rest being labeled by The Encyclopedia of Earth: A Complete Visual ...
5
votes
6answers
397 views

How could you tell if someone was messing around with your gravity?

I'm working on a story involving first contact with an alien species that bases their space travel on directly manipulating gravity fields. My question is not about how that would work, but rather how ...
10
votes
3answers
286 views

Could I use a series of magnetic asteroids to create a magnetic field for mars?

If I push a couple of magnetic asteroids into mars gravitational field, could they form an interlocking series of magnetic fields able to protect mars from solar winds? Size limits for asteroids is ...
5
votes
3answers
178 views

How large does a human’s plastron need to be?

I’m referring to an entomological plastron which is a structure that traps a bubble of air next to the insect's body but permits contact between the air and the water. As the insect consumes oxygen ...
4
votes
2answers
227 views

Astronomy in a universe with two “straight” dimensions plus a highly curved dimension

So for lack of a better term (I'm sure there is a better term) imagine a universe without curvature as being like a sheet of paper. You have left, right, forwards, backwards, up, and down. Now take ...
96
votes
10answers
9k views

Would planets be cubic in my “cuboverse”?

Summary The main idea behind the "cuboverse" is that spacetime distances are measured by (something close to) the sup norm or infinity norm. Under this norm, spheres (the set of points at a fixed ...
10
votes
1answer
155 views

Can Lenz's Law Allow a Simple Block of Metal to Divert a Charged Electron Beam?

I was curious about an odd effect I first saw in video here: YouTube : Copper's Surprising Reaction to Strong Magnets In the video, a big heavy magnet is brought to an abrupt halt by a simple piece ...
4
votes
4answers
183 views

What would the biochemistry of a vacuum dwelling creature look like?

I'm playing around with a story idea that includes vacuum dwelling intelligent life, but I'm not sure I understand the constraints of biochemistry I need to deal with. There's lots of potential ...
-6
votes
3answers
108 views

What is the probability of evolution of Humans to breathe in some other available gas instead of oxygen? [closed]

A general Overview: Due to heavy pollution and the rapid accumulation of greenhouse gases, fresh oxygenated air is decreasingly available in the atmosphere and carbon dioxide levels are rising. (...
6
votes
1answer
174 views

A self-eclipsing orbital ring

A common, matter-efficient science-fiction habitat is a hollow cylinder or ring in space that is spun to simulate the pull of gravity on its interior surface. These habitats have been imagined as ...
4
votes
8answers
522 views

Extinction Equilibrium: 50%

The last time I asked a worldbuilding extinction question, I asked on what sorts of factors would create an extinction event in which 96% of all terrestrial species and only 70% of marine species died ...
9
votes
4answers
257 views

How would a permanently cold tower affect its environment?

In my world, physics works exactly like on Earth, except that there is a narrow, 400 foot tall magical column sticking vertically out of the ground, which is magically always extremely cold -- I'm ...
-2
votes
3answers
57 views

How can I modern time traveler determine solstice and equinox?

A XX century researcher time traveled back into the prehistory. He is not in danger of death or anything, but he has only energy to attempt one jump. He must jump back during the sunrise either in a ...
1
vote
4answers
219 views

How tall do atmosphere retaining walls on rotating space habitats need to be?

A common, matter-efficient science-fiction habitat is a hollow cylinder or ring in space that is spun to simulate the pull of gravity on its interior surface. These habitats have been imagined as ...
14
votes
2answers
518 views

Regrowing body parts: What are the costs?

Everybody has seen superpowers like superstrength, flying, and regeneration. While flying and superstrength are quite straightforward regarding the energy cost, regeneration is not. In this question, ...
3
votes
5answers
305 views

How in a post nuclear apocalypse setting could a group of survivors set up a “Internet” or “Internet-like” service?

In a world set many years (At least a generation or two) after a near extinction level nuclear event, how could a recovering population set up a internet or internet like service? Key points I'm ...
5
votes
1answer
191 views

Energy cost of creating body parts from nothing but energy

What amount of energy would you need to expend to create an arm out of nothing but energy? Of course we have $E = m c^2$ telling us the energy any amount of mass represents. Given the average of a ...
3
votes
2answers
231 views

Could I make a planet with these parameters?

I want a planet that is twice the diameter of earth's but has very similar gravity, atmosphere, and day length. Would doubling the rotational speed of the planet meet these parameters without notable ...
7
votes
5answers
256 views

The Diet of Space Dwellers

I've looked around the forum but didn't find an answer to this particular question. In short, what food could realistically be produced in a space station assuming current (or near future) ...
-1
votes
1answer
97 views

Human Genome, does it hold “secret/lost/inactive” Code shared with animals VIA our Common Ancestors? [closed]

I seem to remember reading that in the human genome there's a lot of "inactive" code, codons that might have been useful millions upon millions of years ago but now have no effect on the human body as ...
10
votes
4answers
344 views

Reality Check: Megafauna and Dinosaurs

Could a planet support both large mammalian megafauna and non-avian dinosaurs at the same time? My worry is that bigger mammals have progressively more trouble with dissipating body heat, whereas ...
1
vote
1answer
223 views

What Would Beaches Look Like if Silicon Didn't Bond to Oxygen?

I was on a beach recently and was contemplating what it would look like if Silicon just didn't bind oxygen very well/at all, perhaps similar to gold. I'm not sure if something else would take the ...
5
votes
2answers
217 views

How big of a coronal mass ejection from the sun do I need to destroy all the electrical equipment on earth

So the background is simple: in the modern day a CME (coronal mass ejection, a solar flare that has escaped the sun) hits the Earth and destroyed all the electrical equipment causing planes to crash ...
3
votes
4answers
117 views

Is a balloon rocket launch pad possible?

Rockets consume a lot of fuel and carry not eough payload. To reduce the fuel needed, why not send it in the mesosphere? Imagine a big balloon, capable of carrying a small rocket to the mesosphere (...
1
vote
1answer
78 views

Chemoautotrophs and human edible food? [closed]

Autotrophs are lifeforms that consume simpler molecules than the large protein, carbohydrate and lipid molecules that heterotrophs like humans ingest, these large molecules are made by autotrophs and ...
7
votes
2answers
237 views

Could I put a large city into geostationary orbit?

I want to put a circular city in geostationary orbit. The city will have a radius of 20Km. I was thinking of using quantum trapping/levitation to achieve this. Here's what quantum trapping is: ...
9
votes
2answers
236 views

How would you heat colonies in the outer solar system (by using natural systems)?

By Colonies 'in' the outer solar system I mean the various moons and space stations past the asteroid belt. Currently the Hegemony has established bio domes, mining stations, and a few large scale ...
23
votes
5answers
5k views

The polar ice caps are melting. Can I replace them with icebergs made of pykrete?

Pretend I'm writing a story about a world exactly like our own. Real world physics, no magic, modern technology. Suddenly an eccentric world leader comes up with the idea to replace the melting ...
6
votes
2answers
123 views

Petri-dish Animals

There's a Thylacine that's found in Tasmania, unfortunately they only found a single female specimen. It it possible to grow Thylacines artificially (say like in an artificial womb) of both male and ...
1
vote
4answers
232 views

Secret Hangar Location Needed for Entropy-sensitive Nano-bots

Premise In this Earth-like world, a multi-billion dollar privately owned aerospace/defense corporation is devising a secret plan to manufacture a fleet of nano-bots. These nano-bot have swarm ...
11
votes
4answers
1k views

What would be an actual real life mechanisms of an accelerated healing factor?

I'm writing a rough sketch for a book about a world where people sorta violently and suddenly get barely working superpowers. That is every time each person uses their power they run the risk of ...
-5
votes
4answers
197 views

Could a person extend their life by having a living blood supplied organ donor? [closed]

An old person and young blooded close match person or clone to get some youth back? With a constant flow of fresh blood the older person the donor is not just donating blood but adding virtually all ...
2
votes
5answers
149 views

Chemical element made with alternative particles

In my earlier question, regarding airships, I mentioned fictional gas, as light as hydrogen but non-flammable. Is it possible to make chemical element, with atoms made not from nucleons, but with some ...
10
votes
5answers
406 views

Is it realistic to “salt the earth” in a kingdom/around a city?

I have a story in which a King, knowing his kingdom will fall, would like to have a scorched earth policy. The King would order all residents to begin salting the earth to ensure nothing there can ...
0
votes
1answer
88 views

How can an intelligent, STL interstellar civilisation emerge on a planet with an ammonia-based biochemistry? [closed]

So, while thinking over the Visitor series, I kind of had this idea that beyond the events of the Sol System, there were four other interstellar civilisations besides the Xwlnnr (also known as the ...
44
votes
6answers
9k views

Can I use a trebuchet to launch satellites into space from a lunar colony?

I've got a lunar colony that struggles to obtain resources, so they're looking for ways to launch satellites into orbit without using up a bunch of rocket fuel. One plucky engineer has suggested ...
5
votes
2answers
156 views

Deep Space Communication Infrastructure

What kind of technology would be required for a space travelling civilization to have an effective communication system or network that is similar in speed to the telegram? How would it work? This is ...
6
votes
6answers
526 views

Could I have an earth-like planet from which sun and moon would never be simultaneously visible?

On earth there can be hours where the moon is up during the same time the sun is in the sky (daytime moon) due to the combined rotation of earth and orbit of the moon. I would like to have an earth-...