New answers tagged physics
3
votes
Accepted
Can Mars disintegrate entirely in this scenario?
Yes, and no need to introduce fast rotation, or nukes or anything similar.
The Roche limit for liquid bodies is $d=2.544R \sqrt[3]{\frac{\rho_M}{\rho_m}}$, where $R$ is the radius of the more massive ...
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11
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Can Mars disintegrate entirely in this scenario?
One part of the question says:
Before the fly-over, Mars's rotation can be accelerated to up to 1 Martian day per hour if that helps Mars to disintegrate.
Would that help Mars break up into pieces?
...
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0
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Can Mars disintegrate entirely in this scenario?
Keeping in mind many of the theories of the Formation and evolution of main rings. And as you mentioned Mars could travels within the Roche limit, Édouard Roche himself proposed that the rings are ...
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2
votes
Using coilguns or VASIMR as thrusters in a game
Induction furnace / coilgun hybrid.
I wince at lasers and fast moving pellets. Much waste, much danger. The horror of moving parts!
I propose instead that you melt your reaction mass using an ...
- 272k
1
vote
Using coilguns or VASIMR as thrusters in a game
Vasimir might be the better option in the sense that on paper at least easily tunable when it comes to your rocket thrust/efficiency ratio. My (lay) opinion would be that assuming the two competing ...
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6
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Accepted
How would the laws of physics need to be adjusted if there really were a preferred frame of reference for FTL?
There's really nothing needed to make a privileged frame consistent with what we currently know - you just have to make it so that the privileged frame is empirically undetectable with any experiment ...
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7
votes
Accepted
Can kinetic energy be converted into cooling?
It is very possible.
You have invented wind.
https://www.cbc.ca/radio/the180/a-lottery-for-senators-it-s-time-to-question-google-s-algorithm-and-wind-chill-1.3898347/the-cold-truth-about-wind-chill-1....
- 272k
1
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How do I create a "magic particle" to make magic work with physics?
Dark matter
Dark matter and dark energy make up most of the universe. Some planets/civilizations/people have whatever it takes to interact with it. The rest of us have no idea; it's only mass to us.
...
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0
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How do I create a "magic particle" to make magic work with physics?
Energon particle
Preservation of energy:
The magic particle can store a maximum amount of energy and then release it later. It normally interacts weakly with matter so can easily go through regular ...
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0
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How do I create a "magic particle" to make magic work with physics?
Frankly, this is the premise of thaumaturgy in The Thaumechanical Man. Thaumaturgy is a field, similar to electromagnetism, mediated by the thaum particle. It behaves a lot like electromagnetism, ...
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0
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Can active-support ringworlds be built?
Here's an option that outperforms mundane materials, but still isn't strong enough.
Consider a stacked series of thin plates of alternating electric charge. Now consider taking such a stack and ...
- 532
0
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Can active-support ringworlds be built?
Helium balloon.
Your scheme should work. The active support structure is spun the way you say, so that gravity and centrifugal force cancel out, with standard Ringworld attitude jets. We fill it ...
- 18.6k
0
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Can active-support ringworlds be built?
Here's one option that (spoilers) doesn't work:
Build a superconducting toroid.
Slowly add current and start spinning it.
The best we can do is a ~10T magnetic field. Let's see how far that gets us.
...
- 532
2
votes
Can you survive a reduction of particle mass?
A regular human has about 5 kg of blood, pumped to a pressure of about 120/80 mmHg.
Suddenly you have 1/1000th of the blood mass being pumped to the same pressure. That outta hurt. The air around you ...
- 125k
2
votes
Accepted
Ballistic properties of unobtainium
Here's a few alternative calculations:
You will have problems when the speed of sound is insufficient to carry the information of the impact far enough to dissipate said impact before the material is ...
- 532
7
votes
Accepted
Can you survive a reduction of particle mass?
It would reduce the mass of the W- and Z-bosons in the atoms that make up your body by a factor of 1000. Which would - due to the uncertainty principle - automatically increase the range of the weak ...
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0
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For a planet with a given equilibrium temperature, what is the maximum pressure possible?
There is no connection, and max pressure can be any.
sure not any any, but no hard limit
Take look at Venus, about the same mass as another well known planet(earth), but pressure on its surface is ...
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2
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For a planet with a given equilibrium temperature, what is the maximum pressure possible?
I'm going to answer the question of how to find the SURFACE pressure, not the MAXIMUM pressure, since you can always just get a higher pressure by digging a hole. With that caveat, here's a rough ...
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0
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How could I calculate the necessary power to kill a fictional beast?
humans used to kill mastodons with flint tipped spears and a fair degree of cunning.
destroying and killing are very different goals.
To be able to calculate the power needed for Destruction one needs ...
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0
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How could I calculate the necessary power to kill a fictional beast?
Trial by Combat
There's a very simple way of determining the best way of how much power and penetration it takes to damage a creature.
Step 1: Capture a dead specimen.
Step 2: Experiment on dead ...
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2
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Can a planet stay cracked?
Even Creating a "Crack" is Impossible
Let alone finding a way to make it stable.
The Chicxulub impact created a geographic feature roughly 20km deep and 200km around. The kinetic energy that ...
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4
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How could I calculate the necessary power to kill a fictional beast?
Hunters and hunting theorists have developed a number of formulae for calculating killing power: https://www.chuckhawks.com/killing_power_formula-2.html
You can take any of these and plug in your game....
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2
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How could I calculate the necessary power to kill a fictional beast?
It's all about placement.
Elephants are about as big as trex's, and people have hunted them with spears. Hit them right and they die.
If your aim is shitty, you need an elephant gun, which is ...
- 23.5k
2
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Can a planet stay cracked?
It's easy to calculate the maximum permanent depth of a local, steep-walled crack in the planet: $Depth=strength/(density*gravity)$.
Hydrostatic pressure in the rock at the crack's bottom can be ...
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1
vote
Ballistic properties of unobtainium
Okay, it seems to me we can reason roughly as follows.
Take the case of a 1 m object impacting at 100 km/s (around the high end of expected natural impact speeds, assuming an object coming from ...
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9
votes
Can a planet stay cracked?
Short answer:
I suggest you use a small, artifically shaped and terraformed mostly iron nickel world to have a crack which is very large absolutely and also relative to the size of the world.
Long ...
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2
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Can a planet stay cracked?
Just have to start calculating pressure, gravity differences of $1500$ km depth. Pressure alone guarantees interesting things happening rapidly.
With density same as earth radius $3500$ km, mass would ...
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25
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Can a planet stay cracked?
No, it couldn't be remotely stable, and erosion is not going to matter.
Even assuming the crack got formed by some very 'gentle' process that didn't destroy the planet outright, you’ve got to consider ...
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5
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Can a planet stay cracked?
No, by definition.
People still debate if Pluto deserves to be called a planet or not. The current definition has three elements:
In orbit around the sun.
Large/massive enough to reach a hydrostatic ...
- 97.1k
38
votes
Can a planet stay cracked?
There is a crack in Mars called Valles Marineris. It is about as long as the contiguous USA.
And here is a 3D rendering of it:
This rift is comparable to your specs in length and width, but not ...
- 125k
9
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Can a planet stay cracked?
Hot Mess:
This is a tricky question to answer. The first big question is, "What caused the crack?" The likely sources of the damage will seriously affect how the crack looks and how it fills ...
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3
votes
Can a planet stay cracked?
No, it is not stable.
It's hard to account for everything that would effect such a scenario, but just to name a few things that would happen, first, all of the liquid water on the planet would try to ...
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16
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Can a planet stay cracked?
The volume of the hole is about 10,500,000,000 cubic kilometers. The density of Earth is about 5,518,000,000 tonnes per cubic kilometer. The mass of the hole was about 6$\cdot$1022 kg. As such, the ...
- 23.5k
2
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Ballistic properties of unobtainium
Boom.
The biggest problem I see with your paraneutronium is that it has no repulsive force. Neutron is stuck to neutron somehow, every femtometer. If a piece of matter hits it, the electrons sail ...
- 18.6k
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