Questions tagged [physics]
For questions regarding the physics relevant to fictitious worlds. General physics may be off-topic.
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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 ...
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Could a planetary object spin at (or near )the speed of light? [closed]
And if so, what would it look like to an observer on the planet and an observer in orbit around the planet?
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Communication between a stationary observer and a spaceship traveling at near lightspeed
I was wondering about the possibilities of communication between a stationary observer and a spaceship traveling at near light-speed(lets say 99.99%). If the observer can send out signals at a certain ...
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Would direct matter to energy conversion be hazardous?
A simple question...
In a setting I am working on, I want most advanced civilizations to use a form of Cymatics to facilitate matter to energy conversion.
They have the technological acumen to "...
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How should I determine the properties of keels and ether?
I was reading this PDF on the speed of sailing ships, and it occured to me that I need to determine the physics of the flying sailing ships in my world. Being flying sailing ships, there will be no ...
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What would happen to an Earth-like planet if it had a more magnetically permeable inner core?
I was contemplating the impact of doping an Earth-like planet's core with a substance that alters its magnetic permeability. Specifically, I considered a scenario where the planet has an improved ...
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What type of security measure/contingent conditions could make jumping into a portal impossible inside a laboratory?
I am writing a spy-adjacent story where one of the characters is able to open and close portals that teleport them to a set number of known locations.
There is a moment in which this character tries ...
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The Wheeler-Feynman Handshake as a mechanism for determining a fictional universal length constant enabling an ansible-like link
I'm writing a science fiction story set in a future where aliens have made contact with us and established interstellar trade.
I'm trying to invent a fairly believable universal standard unit of ...
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What potentially breathable gas behaves the most like a liquid?
So I've already found that Neon seems to be the highest viscosity gas, at least that I can find. However, I don't feel like simply adding a lot of Neon to the atmosphere of my fictional planet of ...
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Could three-dimensional beings engineer a multi-dimensional structure?
Consider the bigger-on-the-inside concept of sci-fi staples like the TARDIS from Doctor Who. A generally accepted explanation for how a space’s interior could be larger than its exterior shape and “...
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Plausibility, habitability and conditions of shell-system
I have some questions regarding the feasibility of this planetary shell-based construction. I have read other questions about shell worlds, but this case has some unique elements, so I thought I would ...
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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 ...
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Could a race create a 1 Megaton non nuclear explosion?
I've been taking a look at Largest artificial non-nuclear explosions . There they mention non nuclear explosions of 3.2 - 2 kilotons occurring 80-100 years ago. Also, one of 4 kilotons around 40 years ...
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How long could a sealed room/building smolder and still be capable of a backdraft/flashover when reopened?
As a hypothetical, say a bad dude decides he needs to burn a home for some reason, but doesn't want the fire to be immediately spotted and responded to. He gets the house sealed up to the point where ...
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This teleporter causes gravitational warping of the user’s body—how come it doesn’t kill them?
So I’ve got a nice point-A-to-point-B teleporter machine, and for some extra flavor I’d like to have the experience of using it include a healthy dose of gravitational/physical warping to push, pull, ...
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High Gravity Giant Shell
I am designing a genus of eusocial, high-temperature, extraterrestrials from the planet 61 Virginis b. They are based on tungsten chloride and use sodium chloride as a solvent. This species has ...
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Decaying Planets
Assume there is this planet with only one type of life; a planet-wide mat of microscopic lithotrophs. These creatures eat through the surface of the planet over time, converting the surface into gas. ...
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Orbital limit for a sapient-habitable moon?
How far does a moon need to be from the roche limit for sapient life to evolve?
This is something I've been wondering about for ages. Life on exomoons seems to be a really unexplored subject in ...
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Is there a material lightning does not strike?
I was imagining the possibilities of creating a ship mast which could not get struck by lightning. Is there a material it could be made of that would never get struck by lightning?
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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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Could a slow rotating planet combined with high density atmosphere create high winds?
I am trying to design an alien ecosystem around a K type star. My idea was to have purple plants and high wind atmosphere so originally I wanted to make it tidally locked. However after watching some ...
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Is using gravitational manipulation to reverse one's center of gravity to walk on ceilings plausible?( in a fictional sense)
While brainstorming for my story I thought of a character utilizing their gravity-controlling ability to "flip" their center of gravity and walking on the ceiling/street pole /side-of-...
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How much energy would it take a person to make an object weighing 10 tons move 10 m/s with an inch punch? [closed]
We assume that the object will withstand the impact. Air resistance and friction force are neglected.
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Stop all mobile phones with EMPs
In this question, I found out that a single EMP is not enough to stop all mobile phones from working. So as a follow-up question: how many EMPs would you need, and how expensive would this be?
To be ...
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How do I store enormous amounts of mechanical energy?
Imagine a typical steampunk setting. Now, let's make two grand assumptions about it:
Steam engines here are MUCH more efficient than those in our world. Yep, we have to violate laws of physics for ...
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EMP that causes all mobile phones to stop working
I know that there exist nonnuclear EMP weapons, but these do not influence the entire world. Could someone build a device that creates an EMP that is powerful enough to make all mobile phones on the ...
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How to create a "fog of war" on an interstellar scale?
I want to create a universe where the visible universe is much smaller than that of our own. The idea is to create a sort of "fog of war" around every star system. In our universe, you can ...
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Elemental Foundry - Quasar powered post-ferrous material fabricator
What is this and what does it do?
(this has got to play in the background)
The the belief that most matter is concentrated in galaxies is false. A relatively huge portion of the matter in our universe ...
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How does a Person survive an intergalactic voayage?
Intergalactic voyages are long, they go over quite large distances, but you, a human in the Milky Way, want to see a galaxy beyond our own with your own eyes and live there. At 99% the speed of light, ...
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Building a settlement in a place in temporal stasis. What problems the settlers would face?
In my low-fantasy world there is a place where the environment has been frozen by magic in some kind of temporal stasis. It's an antarctic type of environment, with mountains and huge ice sheets: ...
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Could a steam-age civilization trial-and-error their way to a nuclear reactor if they had access to enough fissile material?
I think this boils down to a question of how much fundamental understanding is needed to build a very basic nuclear reactor to boil water.
If fissile material was readily available to an otherwise ...
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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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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 ...
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If I move momentum from someone's body to the ground, creating thrust, am I violating the laws of thermodynamics, even though I conserve momentum?
I'm trying to create flight by mathematical adjustments that don't actually violate the laws of thermodynamics. The obvious thing to do would be to neutralize gravity, but that doesn't create ...
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Jail building, escaping from a frictionless hemispherical pit bottom without initial velocity
Imagine a frictionless and rigid hemispherical pit with a radius of 10m on the Earth. For a wizard in my world, it is easy to make such a pit, but hard to build a jail. The pit is the side effect of ...
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What would happen if we expanded the Arctic ice cap?
Having found a setting for my story, I am thinking of a country which encompasses a giant New Zealand, basically a partially surfaced Zealandia, and having studied a little science, I have noticed ...
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Earth, Mirrored-Earth and aliens finding their location [closed]
There is our Earth. In a nearby galaxy there is Mirrored-Earth, much like our planet, with the exception that humans there are flipped left-right wise - so e.g. their hearts are mostly on the right ...
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What are most hydrogen-dense materials that a pre-electric civilization could produce? [closed]
Context
My world has an 'unobtanium' strategic resource that is an alternate form of hydrogen. When atoms of this hydrogen is embedded in a rotor, they generate a field force that pushes against the ...
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What earth crops could be grown on a high gravity (1.5-3g) planet?
I feel like there must be a lot of factors here from the actual structural rigidity of the plants, to how well capillary action functions in higher gravity, to how well cellular mechanisms such as ...
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Fluctuating time between realms?
I'm going to try my best to describe what I'm looking for, but it's a bit hard to explain.
I'm imagining a world with multiple realms and time fluctuates between them according to some sinusoidal wave ...
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How would dimensional travel(similar to Obito's Kamui) work? [closed]
I am writing a story on which several characters are able to create pocket dimensions. For example: character A does this by warping space permanently, through something akin to a programming language,...
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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 ...
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How long would it take us to detect that the earth had been enclosed in a shell 1 light year in radius?
Suppose we put a shell around the solar system that displays a 2D image of the rest of the universe on its inner surface. What year would we have had telescopes powerful enough to determine that this ...
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Millitary applications of a gravity drive [closed]
Let's say gravity drives exist. This is a device that can power a spaceship by creating an artificial gravity well some distance in front of the spaceship that the spaceship perpetually falls into, ...
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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 ...
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What are the repercussions of two asteroids in the asteroid belt colliding?
As the title states, what would happen if two asteroids in the asteroid belt were to collide? Specifically, two the size of 45 Eugina impacting with each other. In my story, I am thinking about having ...
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How do I calculate air pressure at various altitudes within a planet-sized pressurized container?
I'm building a world consisting of floating landmasses located entirely within an indestructible rectangular prism that is 10,000km wide, 10,000km long, and 4,000km tall. If I want air pressures to be ...
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Is there a way to reconcile inertial dampening fields with conservation laws?
So I wish to make a sci fi setting that uses gravity manipulation tech and inertial dampeners.
I have a number of ideas for how such a system works, and about how it should go. At the moment I'm ...
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How feasible would it be if cockroaches no bigger than an inch (2.5 centimetres) took fall damage from around 6-7 feet in the air or less?
Ok, so I have an unfinished/W.I.P world (may turn it into story) about a sapient civilization of cockroaches called Roachins that are pretty much German Cockroachs, but most/many can fly and can stand ...
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How would about a dozen 50 ft to 1,400 ft (approx. 15 m to 430 m) giants wandering around a continent affect seismic activity?
8 of the giants would be around 50-100 ft (15-30 m) and only one would be 1,400 ft (430 m), the other three would be about 500-800 ft (152-243 m). Let's say that they are somehow remarkably light for ...
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