Q&A with a focus on more stringent analysis. Questions and answers should be well-researched, clearly explained, and supported with references, equations, or empirical evidence based on current, widely-accepted science. Please read the category guidelines.
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I've had a number of interesting conversations with people about how the cosmic microwave background (CMB) will evolve in the future. The CMB is the sea of photons left over from the epoch of recom...
Quantum Computers are considered a more powerful type of computer than so called 'classical' computers. While a typical classical computer could be considered as a black box that can solve Polynomi...
In my story, I have a small extended family of 30 to 40 individuals ranging in age from 0 to 50 who are on the run from Chinese and Japanese forces in 1400AD. No place in Asia is safe for them. By...
The known charge-conserving decay modes of free neutrons all involve the production of a proton, an electron and an electron antineutrino: $$n\to p^++e^-+\bar{\nu}_{e}$$ This beta decay is why, out...
Effectively what the title says; What would different observers experience while travelling through / seeing one travel through the tube, and how could they be used to cut travel times? (Just answe...
I'm spitballing a story where the main character goes through a monstrous transformation. Part of the conceit / my enjoyment is that she's an oncology researcher and will be tracking the transform...
I'm working on a computer program which generates realistic planets for worldbuilding purposes. I've run into an issue with calculating my planets heat loss. While radiogenic and tidal heat generat...
The Milky Way and Andromeda will collide a few billion years in the future. Stellar collisions will be rare because - as Douglas Adams put it - "Space is big. Really, really big." In the galactic d...
A young B-type star (with a mass of about 10 M$_{\odot}$) is surrounded by a debris disk extending from about 2 AU to 1000 AU away. The disk has a mass of about 300 Earth masses - enough to form qu...
In this question I asked about the possibilities of what a boundary might be like, with emphasis on the storytelling. Now I'd like to investigate what a hard boundary would mean in quantum mechani...
I have an engine with unlimited $\Delta v$. Don't ask how I got it, it's probably one of my earth changing inventions. Either way: I no longer like Earth and want to get off (I'm headed for a reti...
In 2015 we can rewind the TV, our CCTV footage and, if we wear an action cam, our latest adventure. However if we walk down the street and something happens we didn't quite catch, the annoying fact...
Background In my hard sci-fi settings, there is an advanced Type II Civilization, that are progressing toward Type III Civilization (yes, I am referring to Kardashev Scale). They are sprawling acr...
In the story Wang's Carpets (and part of the novel Diaspora), Greg Egan sketchily describes a high-dimensional universe which contains no analog for light, such that the aliens who inhabit this uni...
Cooling in space is a well known difficulty. There are many unpleasant consequences like no stealth in space, difficult space battles which turn into a short wars of attrition (because you have to ...
On May 18, 1980, Mount Saint Helens made American history with an eruption that took 57 human lives and killed thousands of animals. It has released only a quarter of a cubic mile of ash, but it i...
For the sake of fixing some image in your mind, imagine you want to practice some sport in a rotating cylinder world: whether it be launching a javelin, strike a tee at the golf club or scoring a 3...
I was curious: Suppose we built an O'Neill cylinder with an air mixture similar to Earth's (not pure oxygen). Does the air also get "thrown" down towards the floor of an O'Neill cylinder? If I sta...
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 s...
For the purpose of this post, full spectrum means a non-trivial number of frequencies within a non-trivial band. So human eyes aren't full spectrum within the visual range (each cone is wide band, ...
I know this question has been asked in similar places, but I'm after a specific part of the problem. Assuming the following: Perfectly flat, infinite world Earth's atmosphere Sun directly overhea...
Stun-wizards specialize in blinding and deafening opponents at a distance. To do so, they can exert their magical power to manifest a spherical region of vacuum by essentially "telekinetically" pus...
Humans are not the fastest mammals on the planet, but for very long distances (more than 40 kilometers) we can overtake any species living on land. Except some dogs. The best runners on ultra-long...
In many fantasy worlds, giants are as intelligent as human beings and others races that they either avoid stepping on or step on regularly. However, due to the square cube law, giants have a limit...
So say there was a rogue gas giant about the mass of Jupiter that, unfortunately, happened to be headed directly at Earth (or at least close enough to knock it into an orbit incompatible with life)...
Often, when I'm building a world, I want to start out by determining some of its key properties. Maybe I'm trying to calculate a habitable zone, or figure out how long a year would be on a particul...
I did some research recently for a story on the physical feasibility of some aspects of living in the Saturn cloud deck, and wanted to share it. Please, however, if you have alternate approaches,...
I've been working on designing how an ammonia-ocean world might work and I've settled basically everything except one. I cannot for the life of me find any sources that actually provide a decent wa...
I was in the shower the other day thinking about the sun going Nova, you know...like you do, and a thought occurred to me: Could you turn the sun into a stable, mostly closed system? Some detai...
So we have had multiple questions on having multiple moons and this is another. I did check and didn't find questions that covered this specific setup. I have an earth-like world I am working on, ...
I'm seeking a hard science setting for a piece of xenofiction with a decidedly non-sciencey feel. That said, there is no magic or magic technology. The idea is as follows: A red dwarf star has a...
I'm currently exploring a setting where humans have managed to create traversable wormholes with one critical flaw - something in the wormhole both kills multi-cellular life and destroys electronic...
Inspired by this question, and my own answer to it: Avoiding galactic pandemics. World ending pandemics are a common disaster/after-the-end story trope, I'm trying to determine if plausible, and h...
I have a story where a species of the very first (literally first) carbon-based humanoid life (surprise!) that happen to emerge roughly seven billion years ago (their home system were formed twelve...
One of the cool things about the Moon is that the far side has a thicker crust that the near side.1 One theory explaining this is that the Moon was hit by an object, possibly a moonlet created by t...
For the purpose of this questions, let's assume my crew has solved all those nasty problems of survivability inside the field, not unleashing a devastating blast of particles at their destination, ...
I've been searching for hours, and most formulas I can find use complex/imaginary numbers or variables that I don't know or can't find out (such as the imaginary part of the planet's love number, w...
So, assume that you have 1m$^3$ of normal Terran seawater you can adiabatically raise to an arbitrarily high pressure/temperature in situ (say, by compressing it with nuclear shockwaves from all di...
I am writing a setting for a role-playing game. In it an alchemist has finally found a way to create gold from lesser metals. Like his former historical models the alchemist is so jubilant over hi...
I've mentioned in earlier posts that it will be much cheaper to build immense space-based observatory instruments than to even come close to launching an interstellar expedition. There are several...
As I was thinking about space flight for my world, I thought about how they would need to know a planet's gravitational force before they could land, and found that humans figured out the moon's gr...
I'm working with the idea of creating a sun made out of pure gold. Of course, this would be completely man-made. Why would anyone want to do this? Because I want a cool concept like that in my stor...
I have a planet orbiting a red dwarf and, as expected, it is tidally locked to its star. I know that these planets will have a very significant temperature difference between the diurnal and noctur...
Does anyone know an equation or something along those lines for calculating how many and the locations of atmospheric circulation cells for a planet? Also, does the planet's radius and atmospheric...
Do {any, some, all} {unicellular, multicellular} plants require free oxygen? For example, would a cabbage asphyxiate over night, or even in daylight, in an oxygen-free atmosphere?
Can electricity be generated directly from nuclear decay? It occurred to me that in alpha decay two protons fly off rapidly, leaving their associated electrons behind. If the alpha particle was ca...
Could nuclear energy be a basis for energy storage with foreseeable technology? One approach would be to use excited nuclear states, but I suspect they would be too unstable to ever be useful. Al...
My basic question is could life 'as we know it' (carbon DNA/RNA based, using water as the main solvent in metabolic processes) evolve on a planet where the temperature ranges from 16 degrees Celsiu...
Before we begin, this system is created by aliens, and all orbits are on the same plane. These orbits are similar to earth's in shape. So, none of this has to occur naturally it just has to be stab...
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...
