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There are several previous questions concerning concentric shells. I won't reference them here because this is different. I understand that there is no gravitational effect inside a concentric she...
Now that FTL travel is here there are all sorts of family outings we can go on. One of these is a scale model solar system lovingly made by hobbyist Barty Slartfast. In full scale Sedna is thre...
What would be the diameter and rotational speed of an O'Neill cylinder on the inside surface of which centrifugal and coriolis forces are equal to "gravity" and coriolis force on the surface of Ear...
How can I predict the color of the sky based on the information provided? Atmospheric composition: | 2% Trace gases | 58% Nitrogen | 26% Oxygen | 11% Argon | 3% Carbon dioxide | Average s...
I was wondering if it is possible for life to evolve in a world which lacks any transition metals. I am wondering this because, it could give a plausible explanation for a world which is very unli...
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 ...
Suppose you could pump a load of energy into an asteroid at a safe distance. As energy gets added to the object, does it make sense that this could be done in a way to get the asteroid to different...
Assuming that the only fancy available technology is FTL drives (to get there) plus anything needed to protect and sustain a crew during the journey from Earth to Sagittarius A (whether it takes a ...
I have a planetary system in which there is a huge planet and a moon orbiting it which has an atmosphere and water (and actually everything needed to sustain life). Thing is that I'm sure the mass...
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 lea...
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...
So my story is set in the TRAPPIST-1-system and a rogue planet enters the system. When it's still far off, a scientist discovers that one of the numbers is slightly off. (She has some tables that p...
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...
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 th...
In my fiction I'm setting up a civilization which uses Laser Propulsion for moving things between bodies within a solar system (assume Earth/sun analogy). Laser Units have been set up anchored to a...
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 tidal...
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 s...
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 fr...
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 brough...
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 c...
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 ...
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 differ...
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 ...
I have seen a few similar questions but none seem to take the density of a planet into account. I'm creating a planet on which several small civilisations develop. The planet needs to have a few bi...
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-...
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 ...
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 ...
Think of a giant hemispherical shell, constructed of spaceships, sitting just far enough from Earth to be too far for Earth-based defences and close enough to effectively cast a shadow on the entir...
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...
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 d...
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 piec...
Epimetheus is a planet with about three times the mass of Earth orbiting a sun-like star in the Andromeda galaxy. However, two major factors separate Epimetheus from Earth. First, it has a thick at...
Imagine someone from the modern day somehow gets transported back in time around the same time of WW2 without warning ahead of time. He has with him a laptop, graphing calculator (and a hand full ...
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 s...
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 ...
Previously on the same setting (: How close is too close for a human habitation to be near an erupting volcano? What factors could delay the rescue of a small group of survivors on a Pacific volc...
Throwing big rocks at planets is so passe and any asteroid tug can do that now. The Intergalactic Arms Reduction Treaty forbids the intentional bombardment of a planet's surface with large asteroi...
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 i...
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 questi...
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 s...
This question is a sort of follow-up to Samuel's previous world map question, Creating a realistic world(s) map - planetary systems. Lots of science fiction stories involve journeying to nearby st...
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) technolo...
So, imagine a team of space marines, fighting some sort of space bug zombies on a planet's moon. Things are going pretty bad for them, and the last surviving protagonists are running for their live...
I'm writing a book and I want to use rail-guns for advanced space age factions in warfare. I would like to make them as realistic as possible so I did a bit of digging myself, but most of the inf...
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 notab...
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...
Useless Backstory "Why are you waking me up Sergeant? And why did we enter near-light speed?" "We received a distress call, and there wasn't enough time to notify you, sir." "What kind of distress...
Is it possible that subterranean caves do/have existed on Mars? We know of the past existence of water on Mars. Which region (if any) of Mars would we likely find/expect to find a cave system bel...
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 ...
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 cras...
