The Universe: An open or Closed system

[vincent]

Closed System: Closed systems: Are able to exchange energy (heat and work) but not matter with their environment. A greenhouse is an example of a closed system exchanging heat but not work with its environment. Whether a system exchanges heat, work or both is usually thought of as a property of its boundary.

Open system: exchanging energy (heat and work) and matter with their environment. A boundary allowing matter exchange is called permeable. The ocean would be an example of an open system.

I don't know....

[Fred Derf Veteran]

Space is infinite and thus does not have boundaries.

[vincent]

Space is infinite and thus does not have boundaries.

See, im thinking open system myself.

[Fred Derf Veteran]

See, im thinking open system myself.

It is neither an open system nor a closed system. An open system has permeable boundaries while a closed system has imperiable (or partially permeable) boundaries. Space does not have boundaries and thus neither apply.

I think you are applying finite logic to an infinite problem.

[snyper]

Space may not be infinate..Its just that we dont know.

Its relative. Our solarsystem may only be a tiny part of the make up of somthing greater..

For example if part of an atom was "living" could they comprehend the ocean let aloe the earth, or the solar system or beyond..

[Fred Derf Veteran]

here is a good amount of evidence for the hypothesis that the space is infinite. For example, empirical measurements of the global curvature of spacetime suggest that spacetime is globally flat, which entails that the universe is spatially infinite. Also, the basic theory of inflationary cosmology is now widely accepted, and inflationary cosmology strongly suggests that the universe is spatially infinite.

- http://www.spacetimesociety.org/Monton2.html

[vincent]

Space may not be infinate..Its just that we dont know.

Its relative. Our solarsystem may only be a tiny part of the make up of somthing greater..

For example if part of an atom was "living" could they comprehend the ocean let aloe the earth, or the solar system or beyond..

Well what Fred said makes sense, universe doesn't have any "known" boundaries, I think what you are proposing borders on the line of M-Brane theory, in which (mathematically) energy exchanges take place, so who knows.

[snyper]

I cant accept that space is infinate.

Everything that we have studied has a limit or end to it.

We are just another part of it.

[vincent]

I cant accept that space is infinate.

Everything that we have studied has a limit or end to it.

We are just another part of it.

I lean more to an infinate universe

[Fred Derf Veteran]

I cant accept that space is infinate.

Everything that we have studied has a limit or end to it.

We are just another part of it.

There is a finite limit to observable space. Since light can only travel... well... at the speed of light so thus it can only have travelled a measurable distance from the big bang. The edge of the cosmic light horizon is 15.8 billion light years distant. However, the observable space is expanding into an infinite void. That's is, admittedly, a difficult concept to comprehend.

[_bobcat_ Veteran]

I can't comprehend how the universe could be finite with nothing outside of it.

And if 'outside' is nothingness, then surely that would just be a continuation of the universe, which is mostly nothing.

[Fred Derf Veteran]

I can't comprehend how the universe could be finite with nothing outside of it.

And if 'outisde' is nothingness, then surely that would just be a continuation of the universe, which is mostly nothing.

Incidentally, you might get a planet named after yourself. While "Xena" is choice of the person who discoved our 10th (or 12th) planet, it seems a lot of scientists would rather call it "Persephone".

The discoverer would have had a better chance of getting the thing named "Xena" if he hadn't suggested the name "Gabrielle" for its moon. I'm being serious too.

[davemania]

There is a finite limit to observable space. Since light can only travel... well... at the speed of light so thus it can only have travelled a measurable distance from the big bang. The edge of the cosmic light horizon is 15.8 billion light years distant. However, the observable space is expanding into an infinite void. That's is, admittedly, a difficult concept to comprehend.

If space is infinite than expanse is also infinite which suggests that the big bang didn't began from a single point but from every point at the expanse. This means that space is swelling but its overall size is the same and this matches our observation, all the galaxy seems to be moving away from us rather than away from one single area.

I can't comprehend how the universe could be finite with nothing outside of it.

And if 'outside' is nothingness, then surely that would just be a continuation of the universe, which is mostly nothing.

Outside and boundary is irrevlant if space is infinite.

As for the system thing, it depends on how you define the enviroment. If you go on the path of string theory with muliple dimension, parallel universe, gravitons that drift between them. Who knows :pinch:

Edited August 16, 2006 by davemania

[snyper]

There is a finite limit to observable space. Since light can only travel... well... at the speed of light so thus it can only have travelled a measurable distance from the big bang

Yes, good point, but we cant see that far yet to prove it, so we dont know. do we??

[Fred Derf Veteran]

Yes, good point, but we cant see that far yet to prove it, so we dont know. do we??

We'll we know that the finite space of the observable universe is expanding. If the universe is not infinite then what, exactly, is the observable universe expanding into?

[snyper]

^ i think i need to do some reading...hold this thread..

[dreamz Veteran]

We'll we know that the finite space of the observable universe is expanding. If the universe is not infinite then what, exactly, is the observable universe expanding into?

it's possible that the universe is on some sort of n-dimensional manifold and that there is nothing outside of it. the manifold would continue to expand without there ever being something beyond it. the universe itself would be closed and bounded.

but then is that which the universe is embedded considered the universe? it may very well be that the universe itself is expanding in a finite meta-universe.

[SaLiVa]

I can't base this on facts or anything. I do not have the proper knowledge or ins and outs of this Physical object yet.

I think, the Universe isn't the biggest thing out there. I think there are multiple Universes and a bigger "Universe" to contain these Universes...

[snyper]

I think, the Universe isn't the biggest thing out there. I think there are multiple Universes and a bigger "Universe" to contain these Universes...

Well, as with my original thought that perhaps the entire known universe is only a tiny part of somthing bigger, but what?>

n-dimensional manifold and that there is nothing outside of it

But dreamz, perhaps this is true, but what is nothing? To say there is nothing outside this dimension leaves me back at square 1. What is nothing? There cant be just nothing can there??

[ncc50446]

I think there are more than 1 universe. This is a 11 dimention universe, with other universes on the outside of this one, with more being created all the time, and maybe even some getting destroyed (The big crunch maybe). Saw a show on the science channel that talked about it. Was really interesting.

[Fred Derf Veteran]

I think there are more than 1 universe. This is a 11 dimention universe, with other universes on the outside of this one, with more being created all the time, and maybe even some getting destroyed (The big crunch maybe). Saw a show on the science channel that talked about it. Was really interesting.

It sounds like the PBS/Nova series on "The Elegant Universe" based on the book of the same title by Brian Greene. I watched the three 1hr episodes on HD-PBS and just recently finished the book.

http://www.pbs.org/wgbh/nova/elegant/

Hey, wow, you can watch it online too:

http://www.pbs.org/wgbh/nova/elegant/program.html

[ncc50446]

The show I watched was called "Parallel Universes", was on either the science channel or discovery or something.

Will have to check out that link when I have more time, thanks :)

[Fred Derf Veteran]

The show I watched was called "Parallel Universes", was on either the science channel or discovery or something.

Will have to check out that link when I have more time, thanks :)

Maybe you saw this:

http://www.bbc.co.uk/science/horizon/2001/paralleluni.shtml

I'll keep an eye out for it on TV.

[ncc50446]

ya! That looks like the one I saw! Was really interesting.

[Lqv2015]

This is sort of an off track question but I'm confused.

They say that the Universe is expanding & is speeding up. Now when the Big Bang first started. Did it expand as fast as light speed? And if it's constantly expanding & speeding up, does it ever go faster than the speed of light? I mean, if the Universe is about 15 billion yrs old, and is expanding infinitely, will it ever go pass the speed of light?