Questions tagged [physics]

For questions regarding the physics relevant to fictitious worlds. General physics may be off-topic.

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2
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0answers
35 views

How would a rail gun affect the trajectory of a spacecraft?

What sort of force would a railgun need to produce to have a measurable affect on the trajectory of a large spacecraft? In the scifi book I am working on the primary craft of the story is a military ...
3
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0answers
54 views

Is Santa taking off risk creating a black hole, and will the good kids receive presents survive it? [on hold]

Santa has to visit roughly 822 houses a second on Christmas day. At each house he has to stop, go down the chimney to deliver toys, then take off for the next home in a millisecond's time. As the ...
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2answers
98 views

Is it possible for theoretical particles such as tachyons to interact and/or bond with normal matter

I understand that particles such as tachyons don't really exist and are unlikely, but say for the sake of this question they do. Would these particles bond or interact with atoms? By interactions I ...
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89 views

What would the effect be, if a machine could slow down the speed of light within a field the light travels through? [closed]

I'm writing a story about a fictional character with a fictional invention, one that slows down the speed of light in a field of its influence. I'm wondering what the effect would look like. Could one ...
5
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2answers
280 views

A universe without light?

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 ...
6
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1answer
177 views

Effectiveness of lasers of different wavelengths in space combat

I'm working on a game with combat between spaceships. It will not be hard sci-fi, but I'd like to base the mechanics on (simplifications of) real physics. When it comes to laser-weapons, I would like ...
0
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1answer
52 views

The ability to reduce the movement of particles [closed]

Let's say that there is someone with the ability to reduce the speed of particles' movement (or vibration), he can reduce the movement of molecules, atoms and electrons. I want to know what will this ...
3
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1answer
86 views

Particle Accelerator Explosion

I'm writing a science fiction novel where a linear accelerator buried underground has to explode. Above the linear accelerator is an enormous server room which ideally would be heavily damaged. Atop ...
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1answer
90 views

Turning Fast Radio Bursts into signs of FTL

What would have to be true of the FRBs to make them the result of FTL like the Alcubierre drive? I want a character in a story to discover the secrets to faster than light travel by unravelling Fast ...
4
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2answers
96 views

If the nucleons in an atom were heavier, could it still be stable? [closed]

If the protons and neutrons had, say, a hundred times more mass than they normally do, could the atom overall still be stable? Would it affect the atom's electron cloud somehow, or would it still be ...
4
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1answer
138 views

Designing (a specific kind of) dark matter

There are exactly 2 force laws that can produce stable closed orbits: proportional (spring force) and inverse-square. The inverse square law occurs naturally for monopole central forces in 3 ...
7
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Schwarzschild Metric in a universe with the same space time metric as that described in the orthogonal series, but with massive gravitons?

The universe described in the orthogonal series http://www.gregegan.net/ORTHOGONAL/00/PM.html is one, in which the minus sign in the space time interval is replaced with a plus sign. So this universe ...
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7answers
2k views

How do ballistic trajectories work in a rotating cylinder world?

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 ...
5
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1answer
154 views

How might star formation work in a universe similar to the one described in the orthogonal series?

In our universe, in order for a cloud of gas to collapse into a star it needs to release heat energy in the form of radiation, so that it can cool down enough to collapse into a star. I read what ...
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7answers
283 views

How would a character build an explosive from natural elements?

A character is on an alien planet that is very much like any one of our large deserts. Sort of a Tatooine like on Star Wars. He needs to cause a diversion. There aren't any explosives on planet of ...
3
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2answers
180 views

Ultimate fate of someone falling out of a skyscraper in warped gravity

At the climax of my story, most of the people on the planet have the way they interact with gravity magically altered. Until a week passes or they die (whichever comes first), instead of being pulled ...
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10answers
7k views

How can solar sailed ships be protected from space debris?

So we all know that interstellar starships that travel at high relativistic speeds, like 50% c or above, would be very susceptible to getting destroyed just by a grain of salt hitting it during travel....
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3answers
3k views

Would skyscrapers tip over if people fell sideways?

Suppose that for some reason gravity magically changes, but only for people. While this goes on, instead of gravity pulling people down, it pushes them East. To be clear, it's just people. Not animals,...
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3answers
130 views

Power of flight vs weight of object in free fall

In my story there are people with super powers, but they only get to have one. So, if someone’s power is to start a fire, then they can’t also control it once it starts. My problem currently is with ...
4
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1answer
138 views

What construction and physics implications would there be for life in an underwater “high rise building?” [closed]

I'm working on a project in which part of the story takes place on a planet that is mostly ocean. There is a small continent with some manufacturing and refinery structures, but the rest of the planet'...
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0answers
134 views

Possible FTL travel methods for hard(ish) sci-fi? [closed]

I'm working on a story that requires travel at about convenient* speeds (see below). I want to keep this story as hard sci-fi as possible and I've heard about stuff like Alcubierre drives which sound ...
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4answers
3k views

How fast can a ship with rotating habitats be accelerated?

Alright so I'm not really a physics person by any stretch so forgive me if I butcher some physics jargon on this post. So I'm making this hard sci-fi interstellar ship with a rotating habitat that ...
5
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6answers
356 views

Closed off habitat surrounded by extreme heat, is it impossible in the long term without handwavium? [closed]

High-tech Ents foresee a calamity befalling their beloved and treasured green planet. Surface temperatures will rise well above 500 Celsius (arbitrary, basically just very hot) for thousands of years, ...
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3answers
81 views

Perpetuum Mobile [closed]

Every body knows, that according to Newton's law, isolated vacuum-flask won't spontaneously overheat. Solar-powered machinery would seem sci-fiction in the early times of industrial machinery, now it ...
9
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1answer
221 views

How to build the Cube Prison from Cabin in the Woods?

This question is about the Cube Prison as seen in the 2012 film The Cabin in the Woods. My question is not about the film or its lore, but how the cube prison can be constructed. Specifically, how ...
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0answers
110 views

What would need to be different from Earth in order to make mecha a viable aspect of warfare on a planet? [closed]

There are lots of great questions and answers on this site about how and why bipedal mecha are near useless on earth, and why spiderlike mecha could perhaps have some niche uses which are unlikely to ...
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1answer
76 views

What would life be like on a habitable, non tidally locked planet around a red dwarf? [closed]

A significant portion of one of my stories is planned to take place on Luyten B - https://en.m.wikipedia.org/wiki/Luyten_b - a potentially habitable exoplanet not far from the Sun. This is a rocky ...
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6answers
405 views

Can medieval weapons (swords, spears, polehammers, etc) be more viable than guns in this SciFi setting?

Context In this world, laws of physics are roughly the same as ours. No placeholder magic involved. Wars are fought by cyborgs/mutants/synthetic mutants (super soldiers) who can manipulate certain ...
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2answers
2k views

What would the consequences be of a high number of solar systems being within close proximity to one another?

What would the consequences be of a high number of solar systems being within close proximity to one another? I'm mainly interested in the consequences for life on multiple planets. When I say 'close ...
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10answers
10k views

How can powerful telekinesis avoid violating Newton's 3rd Law?

Characters with powerful telekinesis are portrayed as being able to exert a superhuman force using only their minds. For example, they can throw a car. Based on what I remember from high school ...
3
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3answers
203 views

What is the speed limit on nano-construction?

How fast can nanites work Tangential to the above question. This is for a novel about a somewhat near future. The conceit is that very advanced nanites, plus computers that are able to read our minds,...
5
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1answer
307 views

How would our skies look if our sun was a white dwarf instead?

What I'm using your information for: My planet is small, has a thicker atmosphere than earth and it's orbiting a white dwarf. The main reason I chose it to be a white dwarf is that I read somewhere ...
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5answers
2k views

Could the Missouri River be running while Lake Michigan was frozen several meters deep?

During an ice age, would it be possible for a great lake to be frozen while a relatively nearby river was still running? To help illustrate my point: Would it be possible for Lake Michigan (or parts ...
7
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1answer
175 views

How much energy can I produce per kg of hydrogen using this process?

In the far future the posthuman successors of mankind have disassembled the stars and live on ultra slow and ultra efficient solar system sized computers, Matrioshka Brains. The last enemy of ...
5
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2answers
298 views

Can an object change its own mass?

I was wondering if an object that changes its own mass could exist. But let's try not to fill it up with air or other gas so it feels "lighter". That way you could protect things from being stolen if ...
5
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7answers
400 views

Feasibility of extraterrestrial metals?

In a sci-fi universe where man has the capability to leave our solar system would metals or alloys above and beyond our own be possible? Or at least within the bounds of reasonable possibility? As the ...
6
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7answers
782 views

Compact Mechanical Energy Source

In my late-Victorian world there are independently moving automata that may act as pets or servants to those that can afford them. They require a fair amount of energy to run at full capacity, enough ...
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0answers
71 views

what effect if the world have a single massive world giant tree? [closed]

you know stuff like ygdrasil tree but just a normal tree but the biggest and tallest in the world, i wonder what the effect to the world ? for an example if the root grow to surpass the continental ...
3
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3answers
315 views

Ballistics of a 19.25mm revolver

A lead off from my last question, the actual ballistics of the round. I've learned from the last question and ran some numbers and come up with a basic idea for the ballistics of the revolver. Lead ...
4
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3answers
121 views

Incapacitating an android in magnetized liquid oxygen?

A space opera sultan has a problem. Sentient androids are haram, but an unwelcome android spy has saved his life and helped prevent a coup. Rather than have the android destroyed as his ministers ...
4
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2answers
132 views

What would be the best way for a supernatural entity to fit into a physical body smaller in mass and volume?

Angels are advanced technological beings who are messengers of the gods. These extra-dimensional beings are large, upwards of 30ft tall, and resemble eldritch abominations in their true form, such as ...
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3answers
139 views

Rotation, weight and planet size

Wouldn't it be cool if giant monsters were on giant planets? Of course it would be, but unfortunately physics doesn't really like that idea. Big planets make things on them need more support, so being ...
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7answers
7k views

Could a 19.25mm revolver actually exist?

I'm working on writing a story wherein there is a revolver inspired by Guillermo del Toro's Hellboy's samaritan. My question is; can such a gun, as described below, work? Or would it be a bone breaker ...
2
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2answers
321 views

What is the upper bound for Lightspeed? [closed]

Followup to my lower bound light speed question. I was told on the Sandbox to split the lower and upper bound for light speed in different Questions. Yes they are similar but it is possible that ...
5
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5answers
549 views

What is the lower bound for lightspeed?

I am investigating the possibility of modifying the speed of light in my world. Assuming that the speed of light in a vacuum can (and in my world, is) modified, what lower bound exists that would ...
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3answers
243 views

Biggest possible Steampunk Airship? [duplicate]

I have noticed that one thing that is very common among steampunk airship art is that the size of the decks beneath the gas chamber is outrageously larger than that of the real world. Example: ...
29
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8answers
6k views

Is my plasma cannon concept viable?

I’ve developed a concept for a plasma cannon, and I need it reality-checked. The cannon would gather ammunition by pumping air into the gun through an external fan. The air would gather inside a ...
18
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3answers
4k views

Does water in vacuum form a solid shell or freeze solid?

I'm working on a sci-fi setting which includes an aquatic space-faring species. When a human space vessel is ruptured and depressurizes, the gas can escape rapidly and we immediately suffer from the ...
10
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3answers
464 views

Can I render satellite deployment impossible, or at least impractical, by exploiting the Kessler syndrome?

I want to render impractical the deployment of satellites by exploiting the Kessler syndrome. Why, you ask? Maybe I'm an evil overlord and I don't want those pesky satellites flying over my lair. ...
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5answers
3k views

How would a physicist explain this starship engine?

In my world, interstellar vessels use a drive whose design mankind learned from an extinct elder civilization. While construction of the drives is possible, the physical principles making them work ...