The near-vacuum extending between the planets and stars, containing small amounts of gas and dust. Also called outer space to refer to the physical universe beyond the Earth's atmosphere.
10
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13answers
1k views
What are the mechanics by which Time Dilation and Length Contraction occur?
What are the mechanics of time dilation and length contraction? Going beyond the mathematical equations involving light and the "speed limit of the universe", what is observed is merely a phenomenon ...
5
votes
5answers
629 views
What would ACTUALLY happen to a person jettisoned into space?
[insert obligatory statement of my lack of knowledge in physics]
Alright, so we have all seen the movies where someone gets blasted out of the airlock on their starship, or their suit decompresses ...
4
votes
2answers
828 views
“Artificial gravity” on a rotating space stations
There have been a lot of sci-fi shows recently using the "rotating space station" explanation for gravity on space stations.
After watching these videos:
...
9
votes
1answer
186 views
How vacuous is intergalactic space?
You often hear intergalactic space is an example for a very good vacuum. But how vacuos is space between galaxy clusters and inside a huge void structure? Are there papers quoting a ...
7
votes
3answers
673 views
Can black holes actually merge?
If time stops at the event horizon, can we ever detect two black holes merging? In other words, if you are a short distance away, would you encounter a spherically symmetric gravitational field, or a ...
1
vote
5answers
389 views
what are dimensions?
First, discrete examples.
In a computer screen I can specify any "2D" point with just one single number
(pixel order starting count from first at upper left, and going on, left2right and up2down ...
9
votes
6answers
982 views
Does anything exist in the intergalactic space?
I am a part time physics enthusiast and I seldom wonder about the intergalactic space. First, it is my perception that all(almost all) the objects in the universe are organized in the forms of ...
50
votes
7answers
3k views
How can a black hole produce sound?
I was reading this article from NASA -- it's NASA -- and literally found myself perplexed. The article describes the discovery that black holes emit a "note" that has physical ramifications on the ...
5
votes
3answers
445 views
Will a machine or a technique ever be possible that allows gravity in space?
And I ask out of pure curiosity. I know there is the "Vomit Comet" that allows for a non-gravity 'simulation' (for lack of a better word) on Earth, and I was thinking about if there would be a way to ...
4
votes
2answers
244 views
Sum total distance of electrons on a spherical surface
What is the sum total distance between every possible pair of point charges when there are n point charges on a spherical surface?
All point charges can only and are located on the infinitesimal ...
2
votes
3answers
622 views
If the earth left the solar system for interstellar space. How long would it take for atmosphere to freeze
If the earth left the solar system for some reason. Assuming its moving at the same velocity it's currently exhibiting. How long would it take for the atmosphere to freeze. Would we get methane ...
11
votes
2answers
268 views
Why were space physicists wrong about the location of the heliopause?
The heliopause is now estimated to be something around 100 AU (1 AU = Astronomical unit = about the earth sun distance). See the wikipedia article:
http://en.wikipedia.org/wiki/Heliosphere
From ...
13
votes
2answers
1k views
What is the possibility of a railgun assisted orbital launch?
Basic facts: The world's deepest mine is 2.4 miles deep. Railguns can acheive a muzzle velocity of a projectile on the order of 7.5 km/s. The Earth's escape velocity is 11.2 km/s.
It seems to me ...
1
vote
4answers
1k views
Visualizing Electromagnetic Waves in 3D Space
I did one module of physics for my GCSE one year ago which taught me about transverse EM waves & the EM spectrum, but since then, I do not understand how a wave would move in 3D space. Can someone ...
5
votes
3answers
318 views
An electromagnetic space elevator?
If you surround the equator with a continuous Niobium Tin superconductor ring, and ran somewhere near but less than the maximum current density through, the magnetic field of the Earth would support ...
5
votes
5answers
384 views
Why can't airplanes just keep going up? [duplicate]
Possible Duplicate:
Why do space crafts take off with rockets instead of just ascending like an aircraft until they reach space?
Ignoring that the engines only work in air, so say its a ...
1
vote
0answers
54 views
Could Voyager 1 have entered a solar radiation belt?
We currently believe that the Sun has no radiation belts because the unstable magnetic field, which turns every 11 years, is not stable enough to sustain a solar radiation belt. But observations from ...
14
votes
2answers
2k views
How does space affect the human body (no space suit, no space craft)
How does "outer space" affect the human body? Some movies show it as the body exploding, imploding or even freezing solid.
I know space is essentially a vacuum with 0 pressure and the dispersion of ...
6
votes
4answers
181 views
Direct exposure to the vacuum of space
I was watching a few sci-fi movies and was wondering the real science explaining what would happen if you were to be subject to the conditions of outerspace.
I read the wikipedia article on space ...
5
votes
3answers
772 views
How do they produce air on the ISS?
How do they provide air on the ISS? I know it is produced by electrolysis but is that all they breathe, hydrogen and oxygen? The air here on Earth contains other things like nitrogen. Do the people ...
5
votes
3answers
281 views
Would a fast inter-stellar spaceship benefit from an aerodynamic shape?
Some (generous) assumptions:
We have a spaceship that can reach a reasonable fraction of light speed.
The ship is able to withstand the high energies of matter impacting at that speed.
Given the ...
5
votes
2answers
780 views
Escape Velocity of Asteriod 243 Ida
I was reading about this asteroid (apparently, it has a moon, isn't that awesome?) and I started thinking about if I was on this asteroid, and I jumped, would I fall off?
It's been a while since I ...
3
votes
5answers
390 views
If a space ship accelerated constantly, would its astronauts constantly feel the forward movement?
I know that if a space ship suddenly traveled very fast, its astronauts would be fly against the back wall, potentially getting hurt. If the space ship suddenly stopped, they would also fly against ...
3
votes
1answer
135 views
Keeping air in a well
Let's say I've got an Earth-like planet with no atmosphere: it's just a barren ball of rock. I want to live there, but I don't like domes, so instead I'm just going to dig a big hole and let gravity ...
8
votes
5answers
2k views
If I take a bottle of air into space, and open it, where does it go?
It seems to me that space doesn't have any/much air, and if my bottle is full of air, when I open it, where does the air go?
7
votes
2answers
444 views
What does the sky look like to human eyes from orbit?
There are numerous pictures, obviously, of the blackness of space from the shuttle, the space station, and even the moon. But they all suffer from being from the perspective of a camera, which is not ...
5
votes
2answers
377 views
What's the difference between space and time?
I'm having a hard time understanding how changing space means changing time. In books I've read people are saying "space and time" or "space-time" but never explain what the difference is between the ...
4
votes
5answers
272 views
Does a interstellar spacecraft traveling at relativistic velocity require continous thrust to maintain velocity?
Assuming completely empty space, does a spacecraft traveling at 0.5 C require continuous thrust to avoid deceleration?
If the spacecraft is traveling at 0.5 C, does it's relativistic mass act upon ...
3
votes
2answers
213 views
Do black holes accelerate in spin as they obtain more mass?
It is known that - When a star collapses during the formation of the black hole, the black hole obtains the spin of the star which it collapsed from...
What I'd like to know is, If this spin ...
3
votes
3answers
368 views
How would you move without gravity?
I'm wondering how would you move without gravity? You would still have air pressure at 1Atm.
Would you "swim" in the air or would you have do something else?
2
votes
1answer
786 views
What are the temperatures of objects in Low Earth Orbit (LEO)?
What is the temperature of objects in Low Earth Orbit?
Consider LEO to be 600km to 800km.
2
votes
7answers
2k views
What are the Constraints on Building a Tower to Space?
When I was a boy I used to daydream about building a tower so tall that the top of it would stick out of the top of Earth's atmosphere project into near space.
There would perhaps be a zero gravity ...
1
vote
2answers
147 views
Get into orbit from the Redbull jump position to a satellite position by using a cord/rope?
Its difficult to put this into the title.
I was watching the Redbull Jump and noticed that the height of this is at 39 kilometres (24 mi) the atmosphere pressure is at I believe about 0.4% of that at ...
0
votes
2answers
185 views
Why should space be empty? [duplicate]
Possible Duplicate:
How vacuous is intergalactic space?
The emptiness of space is explained in many articles... But, space does contain some matter due to these possible reasons:
During ...
-4
votes
1answer
220 views
What makes a space a real space?
By "real space" I mean a space in which physical particles move.
Consider a color sphere and let a bunch of objects "move" on its surface. "Move" means "change colors". Let there be some rules ...
