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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41 views

Vacuum chamber in a space rocket? [on hold]

FYI I am a complete noob in the field of rocket design. Question: Why don't space rockets that take off vertically from the ground have a vacuum chamber in the rocket during takeoff? Also, is the ...
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0answers
45 views

Virtual particles and space inflation [on hold]

Could virtual particles be separated by fast inflation of space between them while they were created.
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1answer
77 views

Can you see yourself in space? [closed]

Can one see them self in space if no near by star was in view? Is there enough star light to read once your eyes adjust?
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0answers
15 views

How could you slow down or change direction with photonic propulsion?

So you have a laser shooting at a sort of solar sail to transfer momentum in the forward direction but could you have an onboard laser and turn the laser around to hit another sail? How could you turn ...
0
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0answers
18 views

The force of a vacuum on a breached environment in space

Screenwriter and Physics newbie, not looking for hard numbers, but sort of a general idea of what the force of a breach in a sealed environment in space would be. In films in space, often the ship or ...
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1answer
35 views

Would a literal Air ship (boat) work?

If a set of very large airtight pontoons were made in the vacuum of space, would they float on top of the upper atmosphere? I thought about this while watching the last season of Mythbusters when they ...
4
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1answer
50 views

Will stars disappear from the sky when their particle horizon is outside the event horizon

Given that the universe is expanding at an accelerated rate, will there be a point where stars visible in the night sky will simply disappear from view when their particle horizon is outside the event ...
3
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1answer
36 views

Balloon of ideal gas suddenly pops in the vacuum of space - final average energy per atom?

My question is: is the following thinking pretty much correct? I'm interested hearing about anything here that is fundamentally wrong. Of course there is a bit of hand waving and approximation. If a ...
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0answers
44 views

Why does astronauts hair stick up, and not in other directions?

I understand that in microgravity it doesn't have to fall down, but why does it stick up, instead of each hair-strand going in a random direction?
3
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1answer
59 views

Helmet to helmet in vacuum - can we talk?

Usual SciFi scene. In a spacesuit, in vacuum, with the comms out for some reason. They want to talk, so the butt helmets together so sound can pass through. Questions are: a) Would it really work in ...
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0answers
47 views

Questions regarding space

A difficulty I face is when I think of space. I haven't studied GR or SR yet, but I really want to know what it is. What is space? Is it just the empty place where things are in reality, or something ...
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0answers
30 views

When space containing an extended mass contracts, what delivers or absorbs energy?

As my understanding goes, general relativity and the many theories that have sprung from it allow for the contraction and expansion of space. When such expanding (or contracting) space contains a ...
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0answers
35 views

How to find out diameter of some crater on moon using meteorite size and velocity?

I am looking for a formula to find out the diameter of a crater using meteorite size and velocity.
2
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0answers
68 views

Should we consider space and time as separate entity?

In general relativity, we think of space and time in spacetime framework. As some people say, metric tensor sign difference, along with our inability to go backward in time suggests that space and ...
0
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0answers
43 views

Boiling Water in the Vacuum of Space [duplicate]

In space: When you depressurize ice with a temperature of -72 degrees Celsius would it turn into water? Is there a stable temperature range in which water stays liquid? Does the temperature ...
0
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1answer
141 views

Is space really empty? [duplicate]

This guy here says space is not empty.. It explains how space inside nucleus is Full of fields. Does it mean to say gluons are present everywhere, even outside nucleus? Consider a region without any ...
0
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0answers
26 views

What would happen if another big bang occurred at the centre of the current universe? [duplicate]

If another Big Bang occurred now, at the centre of our universe, what would happen? As the rate of expansion is increasing, the two "layers" (if there were any) would never meet, in which case, would ...
0
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0answers
22 views

Seeing ourselves in the past [duplicate]

If we can see billions of light years into space how do we know we're not looking at our galaxy in the past?
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0answers
38 views

Do relativistic frames imply different realities? [duplicate]

From Einstein's principle of relativity space-time and mass are relative to the frame from which they are being observed. Now would that mean a ball moving at the speed of light wrt to earth would ...
1
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0answers
25 views

Orbital period of a satellite in Kerbal Space Program

Let me start off by saying I am really bad at maths and physics, but lately I have been trying to calculate the orbital period of a satellite I have put in orbit around a planet called Kerbin in a ...
1
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3answers
86 views

Why would we freeze in space if there is no matter to conduct the heat away from us?

If a near perfect vacuum is assumed to be in space, how can heat leak around from our body for example? Although theoretically energy wishes to spread equally all around, it still needs a medium to ...
1
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2answers
49 views

How is the temperature of a star related to gravity?

As far as I know the Sun gets its energy from the fusion reaction, where Hydrogen is converted into Helium. I was watching an episode of Cosmos: A spacetime odyssey. There Neil deGrasse Tyson said, ...
2
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1answer
114 views

Is near light speed travel possible? Likely?

I was contemplating the possibility of sending an interstellar probe that can produce results in a reasonable time frame. For such a mission to be realistic, the spacecraft would have to travel at ...
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2answers
219 views

Red Photon Blue Photon

Why in space red light travels farther and is more observed in dying stars before a star becomes a black hole? while on Earth in water and air the blue light travels the farthest. For example: a ...
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0answers
26 views

Simulating Debris Burn Up Upon Atmospheric Reentry

For work I need to model Debris (1 gram to no more than 1000 km) burn-up upon reentry. I can't seem to find much information regarding this. I feel like I am looking for the wrong terms or something. ...
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0answers
20 views

How to Calculate Pressure From Earth up to Space at Certain Height? [duplicate]

https://en.wikipedia.org/wiki/Vacuum#Measurements_relative_to_1_atm https://en.wikipedia.org/wiki/Pressure_measurement#Thermal_conductivity I wonder if there's a clear equation for this calculation. ...
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2answers
58 views

How does the decaying orbit of a satellite maintain its orbit as it descends, as opposed to crashing straight back to Earth?

I understand that as a satellite in low-Earth orbit experiences atmospheric drag, it is slowed down. Therefore it no longer has the velocity to maintain its orbit at that point, as per the orbital ...
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1answer
29 views

Time dialation as observed on earth

Probably a silli q but, I wanted to know if someone has taken a wind up clock into space and observed time dialation? If all our observations are by electronic methods, we dont know if ...
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2answers
123 views

Why does a light wave fade as it travels through space?

It stands to reason: if it didn't, the entire sky would be covered with stars shining blindingly day and night. But what causes a light wave (or an electromagnetic wave) to fade if there are no ...
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0answers
31 views

How to determine the position of a planet in our solar system? [duplicate]

I am trying to modelize our galaxy with a simple program. I know how to find the period speed and acceleration of a satellite but I don't know how to get the angle and the current distance between ...
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0answers
30 views

Space and absolute 0

If two objects like black holes or soild matter are separated by space, let's assume billions and billions of light years. While all other possible energy has left the area, and no new sources. Like ...
0
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2answers
39 views

What would all the forces on a space elevator be as it moves up and down?

At the bottom, the acceleration due to gravity would be g. At the top, it would be something like .8g... But would the total acceleration effectively be 0 like on the ISS? How would the acceleration ...
0
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3answers
44 views

Looking at past events by observing sky? [duplicate]

Since solar system (and our galaxy) is constantly in motion at a great speed, is it possible that we can look at our own image as it was sometime ago? Since the light of that age takes sometime to ...
1
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1answer
113 views

Why did the big bang happen when it did?

Was there time before the big bang? I assume there wasn't, so is it even logical to ask if there was anything before the big bang? If there was time before the beginning of the universe, what happened ...
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0answers
48 views

Can a spheromak propagate in vacuum?

I recently learned about (and am now fascinated by) spheromaks. I am no expert on plasma physics, but as I understand they are analogous to propagating toroidal vortices (smoke rings), but with plasma ...
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0answers
26 views

How long does it take for space dust to stop irradiating energy?

I heard that space dust is detectable because it irradiates on the infrared part of the spectrum? Does this happen forever? Won't it stop after some millions of years? Does it have to irradiate until ...
2
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0answers
89 views

Can you be your own space suit? [closed]

A few days ago a question was asked on Reddit whether or not a human could survive in space with "just enough" of a spacesuit to plug all the important holes, e.g. a face mask to plug the eyes, ears, ...
0
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1answer
74 views

Can more than one photon be in the same space as another photon?

I have heard light described as a particle that travels in a wave. I have heard that waves are unique in that two waves can take up the same space as they are travelling, either through constructive ...
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1answer
49 views

Effect of redshift on energy conservation [duplicate]

Light coming from galaxies that are going away from us is redshifted. Since the energy of a photon is purely dependent on its frequency one may conclude that the energy of these photons decreases. The ...
3
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0answers
72 views

Why do they think WT1190F is low density?

A piece of space debris WT1190F is in the news in part because it has been far from earth (farther than lunar distance) in the past but will re-enter earth's atmosphere in a few weeks. See this note ...
0
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2answers
204 views

stopping a rotating mass to achieve linear velocity

So I've been thinking about space, and I had this idea. I haven't found any prior art online for it, and from my limited understanding it seems like a viable idea. So I guess my question is, what am I ...
0
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2answers
57 views

Time dilation and reference frame in an orbiting context [closed]

I have looked for other answers, but most confused me more than clarified and did not provide specific calculations. So I am still struggling with this simple question. Consider two persons, $P_a$ ...
3
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2answers
63 views

Liquid seperation in space

We know if we take immiscible liquids of different densities then they form different layers on earth. But when we take them to outer space, they form tiny droplets which are energetically most ...
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4answers
120 views

Why can't a nuclear reactor be used as a rocket motor?

Nuclear fission, and potentially fusion, reactors generate vast amounts of energy, primarily as heat. What stops us from harnessing that energy to propel spacecraft at or above escape velocity from ...
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2answers
50 views

Is it possible for a planetary system to orbit around something that wasn't a sun?

Say for example that at the center of our solar system you replaced the sun, with something that wasn't a star, lets say that it was electrified and still produced the same amount of heat, would that ...
0
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0answers
112 views

How angular momentum conservation is related to the isotropy of space?

In Landau & Lifshitz Vol. 3 Section 54 "Spin" they say: In both classical and quantum mechanics, the law of conservation of angular momentum is a consequence of the isotropy of space with ...
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1answer
50 views

Magnets in microgravity

Lets say you were in a space station in microgravity. If you were to suspend a magnet in the air would it migrate slowly towards the nearest magnetic surface?
2
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1answer
262 views

Does laser beam expand along distance or not? [duplicate]

Why does laser dot become bigger at bigger distance? e.g: from millimeter to inches so that it distracts pilots in aircrafts. I knew that laser beam should't expand over distance, but remain stable. ...
1
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2answers
79 views

Will an object released “upwards” from the ISS continue into the solar system?

Is it possible to release an object from a space station (say the ISS) to make it continue out into the solar system? The most intuitive answer to me (a non-physicist) would be yes, you are in space, ...
6
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1answer
209 views

The effect of relativistic near misses

Alice and Bob are both floating in free, empty space. Alice does not like Bob very much. Thus one day, believing that there is no such thing as overkill, Alice takes her programmable hyper-energetic ...