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.
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36 views
Non-isolated universe and arrow of space
Could you please help me to understand two statements in physics:
1) Universe by definition is an isolated system.
But universe expands, space pours into universe, space (vacuum) has zero-point ...
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0answers
35 views
Solar sail area going to Proxima Centari [closed]
I have a physics question that I need some help with:
"Proxima Centauri is a star in the Alpha Centauri solar system, it’s the
nearest star to our sun (4.24light−years) ...
5
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3answers
87 views
What causes the permittivity and permeability of vacuum?
When light travels through a material, it gets "slowed down" (at least its net speed decreases). The atoms in the material "disturb" the light in some way which causes it to make stops on its path. ...
6
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2answers
135 views
What are the limitations of performing music in space?
Canadian astronaut Chris Hadfield's song Space Oddity is making news around the world today. It makes me wonder: What are the limitations of performing music in space? Clearly, there is no point to ...
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1answer
48 views
Absorption of Water
I was just watching the videos Chris Hadfield put on youtube from space, and was wondering why water doesn't get absorbed as well onto his toothbrush in space?
And what characteristic of ...
6
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3answers
224 views
Why Can We Observe Space Curvature / Warping At All?
I don't understand why we are able to see and measure curvature / warping of space at all.
Space as I understand it determines distances between objects, so if space were "compressed" or warped, ...
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1answer
24 views
What type of Radiation hits Europa
I was recently reading the Wikipedia Page for Europa as I am interested in terra-formation. In one of the sentences, it says that:
The radiation level at the surface of Europa is equivalent to a ...
2
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1answer
53 views
Oberth Effect in deep space
Does the Oberth effect only apply when in orbit of a planet or would a rocket generate more and more thrust (if kept on) even in deep space?
Wikipedia explains that the faster the rocket goes, the ...
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2answers
99 views
What is the fastest a spacecraft can get using gravity-assist?
Assuming normal spacecraft and space objects (no neutron stars, black holes, etc). To what speed can a spacecraft accelerate using gravity-assist?
For example, if a spacecraft is moving at ...
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1answer
47 views
Composition of solar spectrum
I read some where that there are three types of UV and infrared rays namely UV-A, UV-B, UV-C and near infrared, mid infrared and far infrared. Which is the most abundant among the the three in ...
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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 ...
3
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2answers
85 views
Orbit in the vacuum
As the space is a vacuum and there is no friction in space,
Can we assume that, if we place an object in gravity in exactly the right distance from a planet with gravity and in the right acceleration, ...
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2answers
215 views
What is the largest sphere of liquid water that could exist in space held together under it's own gravity? [duplicate]
What is the largest theoretical sphere of liquid water that could exist in space held together under it's own gravity? I've always wondered if a planet the size of earth could exist as a single volume ...
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2answers
83 views
How hot would space feel?
I read that the temperature of the space around the earth can vary greatly depending on whether or not it is in direct sunlight. Space, however, is not very dense, so I imagine that heat would not ...
2
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1answer
58 views
Can a rotating-ring space-station design be applied to a rotating sphere?
Suppose engineers built a rotating space station similar to Space Station V from the film 2001: A Space Odyssey (circa 1968), but with a large sphere, instead of a ring? Could this be rotated or ...
3
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1answer
82 views
Under what practical conditions would Earth's atmosphere be a dilatant?
I have read and heard in many places that when the astronauts of Apollo were coming back to Earth, they had to determine the best angle of attack to re-enter the atmosphere. This is usually indicated ...
3
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1answer
65 views
Would an object float if it were placed in the center of a rotating space station?
Suppose engineers built a large circular room in a rotating space station where if one looked directly up from any location, one could see the floor.
If one used a ladder to reach the center of the ...
3
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3answers
179 views
How do we know for certain that space is expanding?
How do we know for certain that space is expanding?
Let's say that in the year 1950, we observe that galaxy 1 is 5 billion light years away from us and galaxy 2 is 10 billion light years away from ...
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0answers
50 views
Temperature of an Object in Space [closed]
Rotating cylinder in space
Hi all
I've been having problems trying to calculate the temperature of an object in space, and was hoping I could get some help. Say we have a cylinder in space rotating ...
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1answer
148 views
Does Dark Matter have more space-time or particle characteristics?
Dark Matter appears to have more in common with phenomena related to spatial geometry then a particle. I thought in General Relativity, space can be curved without the presence of matter so ...
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1answer
86 views
How much time has passed for Voyager I since it left the Earth, 34 years ago?
34 years have passed since Voyager I took off and it's just crossing the solar system, being approximately at 16.4 light-hours away. How much time have passed for itself, though?
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2answers
127 views
Can Outer Space be used for Waste Disposal?
If harmful toxic, nuclear and other wastes are dangerous if improperly disposed on Earth, can't they be launched into space? If a large, tightly bound mass of waste were to be propelled into outer ...
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2answers
508 views
What is the limit to how many satellites can orbit the earth?
I would like to know how many satellites are physically able to be in place, at the same time, orbiting the earth. Lets ignore which Nations need or use the most satellites (area in space above them) ...
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2answers
44 views
One Particle in a Vacuum
I recently watch a lecture by Neil Tyson where he said the closest thing we have to a vacuum is interstellar space. I believe he said there will be one atom per 1 cubic meter or something close to ...
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1answer
50 views
How much energy is needed to curve the space so the Sun will come 1 meter closer to our planet? [closed]
How much energy/work will it take if our planet is:
5.9736×1024 kg
or
3.0×10−6 Suns
to move Sun and Earth 1 meter closer ...
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2answers
49 views
In space, which would accelerate faster, the space station or an astronaut? [closed]
In space, which would accelerate faster, the space station or an astronaut?
My answer: Both the same, ( no or little gravational friction) but, depending on iniitial force that started the motion.
...
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1answer
61 views
Do all forces act in the same way where gravity is close to zero?
Suppose that I put in the outer space (where gravity from other bodies is negligible) a large, perfectly round sphere totally filled with water. At the bottom (even though "bottom" doesn't make much ...
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2answers
115 views
Is this a great flaw in big bang theory? [duplicate]
Einstein said that, Time & Space cannot exists without one another. Big bang says, time didn't exist before the big bang. So the Primordial ball referred in the Big Bang theory didn't had any ...
3
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1answer
80 views
Influence of air resistance in space
Consider the following situation:
You are locked inside a cylindric container allowing you to move around freely without being in contact with any of the items or surfaces aboard. The container is ...
2
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1answer
323 views
Does the metal foam “whiffleball” orbital reentry idea make any sense?
Planetary Resources is a company speaking publicly about mining near Earth asteroids for resources. I'm interested the physicality of a claim they make in a video here:
...
3
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5answers
398 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 ...
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2answers
108 views
Will a rotating object traveling along a linear path continue to rotate forever in space?
Suppose engineers built a cylinder-shaped space ship which rotates to create artificial gravity:
...
2
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3answers
95 views
What is the relationship between the radius of a ring in a rotating space station and the strength of the artificial gravity generated?
Suppose engineers built a rotating space station similar to Space Station V from the film 2011: A Space Odyssey, but with multiple concentric rings where astronauts can live.
...
2
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1answer
225 views
What are the odds of 2012 DA14 hitting a satellite or the moon?
Asteroid 2012 DA14 will pass by close to Earth. Very close. So close, in fact, that it's inside the orbit of the moon and even inside the orbit of geostationary satellites, as shown by this ...
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7answers
739 views
What grounds the difference between space and time?
We experience space and time very differently. From the point of view of physics, what fundamentally grounds this difference?
Dimensionality (the fact that there are three spatial dimensions but only ...
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2answers
81 views
Is there a map of the particles in outer space?
Since outer space is not quite a vacuum, and the distribution of various heavenly bodies is locally inhomogeneous, it seems reasonable to expect that the density and variety of particles ...
3
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3answers
124 views
Temperature in space
Temperature is a measure of kinetic energy transferred to particles, henceforth, space being vacuum, temperature cannot be measured.
But then, there is cosmic background radiation. It is the leftover ...
2
votes
2answers
126 views
Curved space or curved spacetime?
As I understand it, you can have time + flat space = curved spacetime.
So, when one is trying to emphasise that there is a curvature to the space, is it more technically correct to say curved space ...
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0answers
28 views
How do stars look like from space? [duplicate]
Possible Duplicate:
Optical explanation of images of stars?
What are these rays that appear in photograph of sun?
I thought stars should look round shaped (similar to a sphere, or oblate ...
2
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1answer
395 views
How does sound travel in space?
In relation to this question:
How can a black hole produce sound?
Which notes that the hole "produces" sound. The top answer states that:
What you think of as the hard vacuum of outer space ...
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2answers
193 views
Spaceships travelling through space and debris
How can a spaceship travel through space if there is space debris flying around at very high speeds?
Wouldn't even a small rock crack through the spaceship?
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1answer
96 views
What's wrong with this reactionless drive?
I think this is analogues for the Woodward effect, but macroscopic:
We assume a spacecraft consisting of a broomstick, a donut and lots of gear for storing and transfering mechanical energy.
Take the ...
50
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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 ...
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4answers
747 views
Why can't a spaceship accelerate for ever? Since there is no friction in space
I have seen many answers like: because we don't have infinite energy, because of gravity, because it is impossible, because of physics.
But they don't really answer my question.. I mean if there is ...
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3answers
199 views
Can one heat up a vacuum?
I've got a question about heating a vacuum. If there were, say, a container in space, at 2.7 degrees kelvin (the typical temperature of space, if I'm not mistaken) and as empty as space (as close to ...
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2answers
190 views
In a spaceship, if a vessel suddently stops will an object inside the vessel keep going?
My question is a 2 part question.
First if a vessel in space is going very fast and suddently stops (maybe it is not possible but that is not the point) will things/humans inside the vessel keep ...
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2answers
87 views
Could a spacecraft dock with the voyager 1?
Is the Voyager 1 (or any similar exploration spacecraft) equipped with the ability for space to dock with it (attach to it)?
Hypothetically, if a voyager or similar spacecraft were in Earth's orbit, ...
0
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1answer
87 views
How could the relative zero gravity of the International Space Station be canceled? [duplicate]
Possible Duplicate:
Will a machine or a technique ever be possible that allows gravity in space?
I'm wondering how it would be possible for science to cancel out the experience of zero ...
5
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2answers
380 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 ...
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3answers
795 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 ...
