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Question: is vacuum in space real?


JERONIMO

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Depends on how you define it.

If you mean are there vast swathes of space, like light years on a side, with 0 particles at all? No. Probably not many even a meter on a side though I'll admit I don't know the actual densities and probabilities involved.

Are there points in space where there is no mass at all? Yes. An infinite number. In fact there are an infinite number in the area directly around you, and even inside you.

And don't even think about quantum particles.

Edited by 5thHorseman
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Well, if I think of vacuum in space, then this comes to mind...

R2gIBZk.jpg

But what we think of as vacuum is merely an area with a much lower gaseous pressure than what's around it, causing gases to flow from the higher pressure area to the lower pressure area. But deep space has a much "purer” vacuum than anything we've created on Earth, with the possible exception of some specialized labs.

Edited by StrandedonEarth
Finally noticed a punctuation typo
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I mean The question is what constitutes space. In atomosphere boxes or out of atmosphere boxes could be void of all particles. Do you define protons as I'n a vacuum as they have drag on a craft however they are not atoms. I guess somewhere on space a complete vacuum exist but I think  it is rare. 

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Accepting the Big Bang theory, where all the mass and energy in the Universe is expanding, one can reason that anything beyond the current borders of the Universe is a complete vacuum - as there's nothing there yet - not even light. 

But one can reason that that is not vacuum, but plain nothingness. 

Other than that, no. There're not a vacuum as you defined. There're energy spreading everywhere, from light to gravitrons. And these things are something. 

There are places without matter. And that's it.

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5 hours ago, JERONIMO said:

i mean, space vacuum has nothing in it, but there are some hydrogen, photons and other thing in space. so does vacuum really exist as we think of it?

Yep, an absolute vacuum does not exist afaik. The particle density in space is very low, compared to our environment. Though it varies greatly between the inner solar system, the space between stars and between galaxies and so on.

 

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5 hours ago, JERONIMO said:

my question is at least partially anwsered if haven't been fully

Basically :

Yes, it's technically a vacuum. A very good one at that.

Is it devoid of particles ? No.

But it's better than other things - we used to have vacuum / steam brakes on steam trains, and it's definitely not as good as interstellar or intergalactic vacuum, but we still call it a vacuum regardless.

 

But this revelation can go on : first is the absurdly small scales of an atom - the nucleus is barelg the size of anything, whereas electrons are just things flying around - so most of atoms are empty.

And yeah... as it turns out, empty space isn't that empty...

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Is "space" real? Are length and breadth and width real? Is there such a thing as "empty space"? Is "nothing" something? Perhaps there is no "spooky action at a distance" because there is no such thing as distance.

We used to think of distance as some kind of rigid frame, although folks like Zeno wondered if it were really possible for there to be empty space between things. Then Einstein and others taught us to think of space and time as some kind of field equation, which can be distorted. "Space" and "Time" are not independent. String theory describes many more dimensions than these. And what about inflation? Was there "space" before the Big Bang?

And what about the idea that the universe is a simulation? If I make a computer model of a 3-d object, like a steel beam, are those three dimensions real? Inside the computer, if I make the beam twice as long, do I take up twice as much memory in the computer? No, the dimensions of the beam in the computer are just numbers, not physical dimensions. Well, if it's really true that there is no way to tell from the inside whether the universe is a simulation or not, then is there any way to tell for sure that what we think are dimensions actually exist? If Jeb flies from Minmus to Jool in my computer, has anything actually crossed any space? Or did some numbers in my computer just change to other numbers?

Edited by mikegarrison
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1 hour ago, mikegarrison said:

... if I make the beam twice as long, do I take up twice as much memory in the computer? No, the dimensions of the beam in the computer are just numbers, not physical dimensions. ...

The data (position vertices describing the corners of the beam) doesn't even change. Scaling is just a matrix multiplication :-)

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1 hour ago, mikegarrison said:

Then Einstein and others taught us to think of space and time as some kind of field equation, which can be distorted.

Equations are only there for us to help understand reality - the truth may well be far removed from these simplifications.

11 minutes ago, Green Baron said:

Scaling is just a matrix multiplication :-)

... and so is coordinate transformation.

But in reality, they don't exist - it's just a nifty way to predict what would happen, and we might be wrong still.

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I'm with Einstein on this one. Spacetime is everywhere..

Its all to do with what you are looking at/for and how significant the effect is. For example if a gravity field from a body had a trillianth, billianth of an effect on the path of my particle, you might ask is it significant? The answer is clearly no. Is it absolute and correct to say it had no effect. No that is incorrect also because it may have a very very small effect but it is still there..

It depends what you are looking for and how much it can skew your data.

Maybe it is time to redefine the word vacuum. At lower level science it is commonly tought as being an empty space for learning purposes. We now know that it is not that simple.

Science gets complicated sometimes and i'm all for keeping it as simple as we can. 

On earth we consider gravity as the weak force. By comparison to electromagnetism and the other forces this is maybe true, albeit whilst on earth. If you observe the curved paths objects take through space due to gravity/spacetime it becomes a lot more significant in that context.

When we slingshot a spacecraft around a planet to reach further into the solar system gravity becomes more significant. Without it the flight plan would look a whole lot different.

Its all to do with context relative to what your looking for.

"A vacuum is space devoid of matter" if there ever is such a thing

Edited by Starstruck69
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We should remember that "vacuum" is just a statistical term. A hit count per second defines is it vacuum or not.

So, while you are getting lower and lower, you should decide if count only moleculas hits, or particles, too. And whether count the virtual particles.

At last you get lost in the quark-gluonic mess.

Edited by kerbiloid
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1 hour ago, kerbiloid said:

We should remember that "vacuum" is just a statistical term. A hit count per second defines is it vacuum or not.

So, while you are getting lower and lower, you should decide if count only moleculas hits, or particles, too. And whether count the virtual particles.

At last you get lost in the quark-gluonic mess.

Not forgetting dark matter! The plot thickens.

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