Questions tagged [hard-science]
REVIEW THE WIKI BEFORE USING THIS TAG! For questions that require unequivocal proof that answers are correct through the use of equations, empirical evidence, scientific papers, etc. Compare to: science-fiction, science-based and internal-consistency. This tag may not be used alone. This tag may not be used with the science-fiction, science-based, or internal-consistency tags. Flag your question for moderator attention once posted.
975
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Do Forbidden Lines in Stars Often Come in Groups
In previous questions, I asked about how a K2V star could develop an [O VII] forbidden line and how those x-rays would create "pseudo-aurorae". Now, I'd like to know if my star could ...
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1
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Finding a stable atmosphere for a different gravity
I am trying to find what would be a stable atmosphere for a planet, using this https://docs.google.com/spreadsheets/d/1cW7BIWlBUscqS9MVqs5gSbPH0OGzyE-j2cz6ADBSVzE/edit#gid=0 (you have to make a copy ...
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Visibility of My "Psuedo-Aurorae"
I have been designing a habitable planet, its moon, and its star for a while now.
Background
My star is a K2V star with very strong solar wind and is about the age of the Sun. Every so often, when the ...
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1
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How could a K star develop an [O VII] Forbidden Line at 22.1 Å
The Goal
I have been designing a planet for quite a while now, and I would like the star to have an [O VII] forbidden line in its atmosphere. There doesn't need to be too much, but I need enough for ...
- 779
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1
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How do human girls who are sterilised at age 9 develop as they mature?
On the world of Ruquelis, there are three genders, men, women, and lilim who are a female sex, with wings and clawed feet. Because of the genetics of this situation, lilim are less fertile and can ...
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Amount of antimatter needed to propel large spacecraft?
Okay, So i'm not really into physics or mathematics but i'm trying my best to learn some bit of how the calculations needed for the amount of antimatter needed to propel a spacecrafft to relativistic ...
- 567
2
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1
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Exomoon Color as Viewed from Planet It Orbits
I have been designing a planet and it has one moon that is slightly smaller than ours. Just like how mars appears red and its dust is red, I realized that maybe if I altered the composition of my moon,...
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1
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How could a planet accumulate xenon in its atmosphere?
I am currently creating a planet with an atmosphere rich in noble gasses, especially neon, xenon, and argon. It's composition is roughly about this:
Nitrogen (N2) - 61.5%
Oxygen (O2) - 21%
Neon (Ne) -...
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1
answer
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Ammonia transporting blood
Okay essentially I am designing an alien ecosystem with an ammonia and methane based metabolism. Here's the formula for the metabolism animal analogs use on this planet:
$$\ce{3CH2O + 4NH3 -> 3CH4 +...
- 1,222
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2
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How deep underwater can red photosynthesis work?
The Setting:
I have a binary star system.
First star: K5.2V class Orange Dwarf, 60% the mass of Sol, 17% luminosity of Sol, and at 4.5 billion years old. This star is the only one with a planetary ...
- 1,692
3
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2
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Fire Analogue on Hydrogen Methane atmosphere Planet
Okay to summarize I have a planet with an approximate atmosphere of 44% nitrogen gas, 30% hydrogen gas, 23% methane and 3% other trace gases. I am working on an intelligent alien race on this planet ...
- 1,222
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1
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Partially tidally locked planed due to elliptical orbit... Possible?
Would it be possible for a planet with an elliptical orbit to be tidally locked to a star, only for a certain part of it's orbit?
If this is possible, then:
could the tidally locked side vary from ...
- 593
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3
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Would lenses work in a universe with four spatial dimensions?
Let us assume that we have a universe with four spatial dimensions rather than the three of our universe, in which matter can exist that is a four-dimensional analogue of three-dimensional matter.
...
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1
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Zero energy transfer between Earth and Moon with space elevators
I'm asking this out of curiosity, mostly as a response to Space elevator from Earth to Moon with multiple temporary anchors and some of the comments and answers there.
Suppose you're able to build ...
- 4,594
4
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2
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117
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Trinary star system - Tidal locked planet [closed]
I'm trying to build a world where an earth-like planet is tidal locked to a sun in a three star system, where the other two would orbit each other in the center (being the central mass of the system). ...
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2
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What kind of scanner can detect a hidden chip in someone's body?
So it's the lead-up to what might be World War III and the enemy is kidnapping and implanting mind-control chips into our people, one by one, to turn them into sleeper agents, to all attack en masse ...
- 139
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4
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How small can a nuclear weapon get?
Context
I am writing the section following a critical space battle where a rogue UNN Pearl of the Stars is taken down, and its CIC, reactor and, most importantly, its payload of 4 planet buster 15-...
- 1,984
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1
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How large should my supermassive planet's core be to prevent it from becoming a star?
My planet is a gas giant, it is called Klarloth (Inspired by a character from "Star Mouse" by Fredric Brown).
Klarloth is a strange planet. For one thing, the planet is large in size, more ...
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2
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How many different mines and extraction industries would a colony need in order to be able to produce equipment similar to what we have now?
Help me, you benevolent geology nerd!
This is a question I'm trying to find a workable (but not necessarily precise) answer for a colony-building sci-fi RPG game that I am GMing for some of my friends....
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2
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Calculating the total thermal energy contained within an object [closed]
A character in my world has a superpower that allows them to convert all (or at least 99.99...%) of the thermal energy contained by the particles within a volume into directed kinetic energy, causing ...
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2
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How could a remote controlled bacterium work?
How could a radiowave controlled remote-controlled bacterium be possible?
Criteria:
The receiver for the radiowaves would not be bigger than the bacterium (which is the size of a cyanobacterium)
The ...
- 459
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1
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How the sky will change with stratospheric aerosol injections?
The world I am designing has successfully survived the event of the almost complete depletion of natural oil reserves. By "successfully" I mean that cities are densely populated, the stock ...
- 1,148
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2
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Do the mountains formed by a divergent boundary form on either coast of the resulting channel, or on the part that has not yet separated?
The lakes and the bay are formed by the rift where the right chunk is diverging away from the main plate. I've put mountains on the land part of the rift a la Ethiopia's Great Rift Valley, but should ...
3
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2
answers
567
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Physics feasibility of a light-gas driven rifle cartridge? Diagram example included
The idea would be a typical rifle cartridge with a case and propellant but with a gas section placed between the case and propellant and bullet with a soft metal disc that would be driven by the ...
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3
votes
1
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194
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Is a universe with a very low speed of light possible? [closed]
In my universe, the speed of light is measured at 5m/s. Now, these aren't meters as we know them, since if all it was is just to change $c$, then the scale of everything else would change with it, and ...
- 183
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4
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How does one accurately deduce scale from any given fantasy map (to the best one can)?
Sometimes, a person might wish to know the touch scale of a map, whether made by another person or you, in order to better understand the world a story is taking place. How might one go about deducing ...
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5
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Would a weapon made of a piezoelectric material be able to notably shock an opponent?
In my world, people are able to use magic to produce piezoelectric materials of a high strength, making it a viable material for use in weapons and armour. For the purpose of this question you can ...
- 1,784
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How close can two planets be within the habitable zone?
I am aware that similar questions have been asked but these variables are different. I have tried to calculate it myself or at least find an equation that could help find the forbidden zones for these ...
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2
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How to calculate the density contribution of each of Earths layers
I'm trying to calculate the density of planets a bit more precise, than just treating it like an object of uniform density.
In order to do so, I went with Earth, as my convenient sample planet. Earth ...
- 593
3
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1
answer
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How much diamagnetic levitation can a human handle?
One of the limitations to human space travel is acceleration limits. We'd really like to just shoot spaceships out of a cannon to 99% the speed of light, but the resulting pressures on the human body ...
- 12.6k
6
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1
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On the tidal heating of a moon. What is the second Love number?
Years ago it was asked here how to calculate the tidal heating of a moon orbiting another body with a simple equation. The answer is very detailed. They explain the equation, its shortcomings, the ...
2
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3
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Is there a NON-CHEMICAL weapon that can target the central nervous and/or muscular system?
There is research on nerve agents and gases, but are there any man-portable weapons that may be able to harm the CNS without gas? Thanks.
AMENDED: Results in symptoms like shaking, tremors that are ...
12
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1
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How old must The Moon be?
Some time ago, aliens placed the Moon around Earth with every intent to deceive us about its authenticity, except for the glaring synchronization that allows for total solar eclipses, as something ...
- 5,937
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1
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What is the climate of an otherwise ocean planet with a huge landmass along the equator? [closed]
I am coming up with a new planet idea inspired by One Piece. I'm imagining a planet with the same mass, volume, and sunshine as Earth. The difference is that it is mainly an ocean planet. There are no ...
- 2,608
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1
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Can you use plants as substitute for missing metals/elements?
Say a person stranded in time, somewhere in a forest wants to make brass.
He has copper, but not zinc, so he tosses a bunch of zinc-rich beans and nuts in the smelting pot with copper and prays to god ...
- 55
2
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3
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Gravity-powered cannonballs for mountain dwellers
My mountain dwellers have endless patience. They spend their spare time fashioning spherical rock cannonballs of approximately equal size. This is in case of attack by enemies. Around their mountain ...
- 49.3k
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2
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Could a desert animal recycle ammonia into protein to avoid urinating?
Could a desert animal, with the right symbiotic microbes, avert the need to urinate by creating ammonia and having bacteria in its blood/kidneys convert it into nitrate and then back into amino acids? ...
- 15.5k
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1
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How much lift would this multi-winged flying ship generate at 100 kph?
I would ask on aviation, but since this is a hypothetical aircraft, it isn't allowed there.
Context:
In this alternate history dieselpunk world there are the military branch of the "aeronavy&...
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2
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What color should my planet's skies be?
Assuming the skies are clear of suspended particles, what color should they be at mid-day if viewed with human eyes?
The planet is larger and twice as massive as Earth, with a nearly identical ...
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2
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2
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Spaceship habitat size
I need a spaceship habitat for a million humans, comfortably, for indefinite time.
I have read many questions around here, perfectly answered, about the size a spaceship should be to store enough ...
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4
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Does this alternate Universe with easier-to-understand physics behave the same as ours?
I realize the following question is non-trivial, but I would greatly appreciate any all help.
I'm interested in creating a SciFi story that takes place in an alternate universe I'm calling Universe X. ...
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2
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What would be the different climates of an island six time the size of Madagascar in longitude and latitude near the west of the Drake passage? [closed]
I have 4 geographic peculiarities to take into account that could influence the climate :
The island is surrounded by a chain of mountains(oceanic ridges) that can protect the coastline from ...
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3
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Alt. Biochemistry - Which of these is a suitable alternative/mirror to DNA?
This question is tied to the “Glass Trees” question I asked earlier which everyone seemed to like. Since y’all had such good opinions on that, I figured I’d bring this particular quandary to y’all in ...
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4
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Glass Trees - how feasible is it?
Edit: For clarification, this question is in regards to silicate use in carbon-based biochemistry, not silica-based biochemistries.
The microorganisms you see above are called diatoms; they are a ...
- 1,692
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6
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Need counters for a near perfect Anti Thermal and Kinetic armor system in a near future setting
So I have an armor that is virtually impervious to small arms fire, and am looking for inspiration and suggestions on an unconventional way to defeat said armor.
The armor is called Anti Thermal And ...
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3
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Would compound-like eyes that gave a "pixelated" image be possible/practical
The title is horribly worded, but I have no idea how to otherwise title it.
Basically, the idea behind these special eyes is that they would be structured much like real-life compound eyes, but the ...
8
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5
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A person in the air being struck by lightning
In the climax of a story I'm writing, the antagonist is flying high in the sky(she has wings) during a thunderstorm, while wearing a full suit of armor. She is struck, and nearly killed. But lightning ...
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4
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3
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How far away can (non-dusty) rocket exhaust be detected?
There are several questions around regarding stealth in space, where the general conclusion is that stealth is not really feasible because (among other things) heat radiation from a spaceship doing ...
- 1,384
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6
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Can a gunsafe survive a nuclear blast level attack?
For reference, here is a type of safe I am talking about: Gun safes are extremely strong, they are on the more expensive end made with solid steel plates. But I am unsure whether something like that ...
- 135
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3
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Suppose an array of mirrors 50 km above the surface reflect light straight down. How long before the sun rise are they illuminated?
Suppose at a point in the earth’s future, a superstructure has been built at the northern 45 parallel. 50 kilometers above sea level, a large array of mirrors has been built. The mirrors are ...
