The infinite space of the Universe

With this topic i'd like to discuss what problems would arise if we accept the idea that the space in the universe is infinite. Could this mean we have a very wrong idea about what "to exist" means? Wouldn't this mean that physical existence is impossible and life is an illusional perception of our minds? What scientific explanation could be given for the existence of an infinite universe? Wouldn't the existence of endless space automatically rule out the existence of parallel universes, a creator, a beginning, an end, a purpose? If we assume that the space of the universe is finite, what could happen when the expansion of the observable universe reaches the boundaries? Edited by Agobot, : No reason given.

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Don't you think it's a bit too early to ask these kinds of questions? The only way to answer these questions is to simply pull stuff out of your ass like religionists do all the time. But for the rest of us heathens, give us a few million years then we'll have an answer for you.
  —Taz

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"Hypothesis"I think somebody came up with this word many centuries ago. I really think it might be beneficial for this discussion...As for my personal opinion - life being so meaningless as it is, I think an infinite universe will just add more meaninglessness to the picture. Through my eyes, the whole universe looks like an aweful waste of matter and space and everyone looking for a meaning will meet a wall of indifference, coldness and lack of meaning and purpose. So, yes an infinite universe fits quite nicely in the picture of things. Edited by Agobot, : No reason given.Edited by Agobot, : No reason given.

Wouldn't this mean that some of the galaxies at the far end of the universe would be turning up at the other end of the universe? So far(and i mean for the last 13.7 billion years) we have observed a constant and seemingly never-ending expansion of the universe. Will it ever reach a barrier? We don't know, but we do know that space is bigger than 30 billion light years across. And i see no reason to believe the expansion will ever hit a wall.Edited by Agobot, : No reason given.

Just to add some more controversy to the issue - an infinite space in the universe will pose new unknown problems. Like the infinite numbers of Big Bangs, infinite number of galaxies, stars and planets, infinte forms of life, infinite number of human twins, etc. It just doesn't make a whole lot of sense(not that the observable universe does anyway).Edited by Agobot, : No reason given.

By Universe you mean space, right? So what's the difference between unbounded space and infinite space? A spherical model? What evidence is there to support this theory?EDIT: Ooops. Spherical model of 3D empty space doesn't make too much senseEdited by Agobot, : No reason given.Edited by Agobot, : No reason given.

Einstein is not helping us either:"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."-Albert EinsteinEdited by Agobot, : No reason given.

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Unbounded space can be finite while not having an "end" to it.

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The two dimensional surface of the Earth is finite and unbounded. You can go in the east direction forever while remaining on a finite surface.
  —Catholic Scientist

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There is no 2-dimensional surface in a 3 dimensional material world. Anything out there and around us is 3 dimensional. 2-dimensional could only be something imaginary.

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Let me guess... You never googled "evidence for a finite universe", did you?
  —Catholic Scientist

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I did. This theory is refuted in more web sites than you'll find it being promoted.Regardless, what's the meaning in the English language of:"Unbounded but finite, spherical empty 3 dimensional space" ?English is my third language and I can't really grasp it. I can't even picture it.Edited by Agobot, : No reason given.Edited by Agobot, : No reason given.Edited by Agobot, : No reason given.Edited by Agobot, : No reason given.

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Astronomers are interested in how strong different sizes of ripples are, as this reveals vital information about the early Universe, and might tell us how big the Universe is today. Many astronomers suspect that the Universe is infinite.
In that case, the microwave background ripples should have an unlimited range of sizes. But while WMAP's observations of small-scale ripples have matched predictions for an infinite Universe almost perfectly, the large-scale measurements have not. On the largest scales, WMAP has shown that the ripples almost disappear (see graphic, top).
  —Catholic Scientist

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Correct me if I am wrong, but I think they are talking about the material universe being finite(galaxies), which is vastly different to space being finite or not.

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Regardless, what's the meaning in the English language of:
"Unbounded but finite, spherical empty 3 dimensional space" ?

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English is my third language and I can't really grasp it. I can't even picture it.
  —Agobot

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I'm sorry but I doubt I could help much with that.
  —Catholic Scientist

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LOL. You said the space in the Universe if finite but unbounded/I quoted that/. Then you gave an example with the spherical shape of the Earth as being finite and unbounded. And now you don't know what you have meant by "finite but unbounded spherical 3-dimensional empty space"?BTW, you have a wrong idea about the theory of the unbounded but finite universe. It only applies to the material portion of the universe(galaxies). It does not apply to the seemingly infinite empty 3-dimension space of the Universe(of which we talk about here and which is beyond the last, farthest galaxies).Edited by Agobot, : No reason given.Edited by Agobot, : No reason given.Edited by Agobot, : No reason given.

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I think they are talking about the material universe being finite(galaxies), which is vastly different to space being finite or not.
  —Agobot

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You are wrong - they are talking about space being finite - in the manner that Catholic Scientist has described to you. Travel in any direction in the Universe, and without deviating from your straight path, you will eventually return to where you started. This is almost certainly practically impossible, because the expansion of the Universe will outpace your attempt to reach your starting point. If the expansion should slow and halt, then it may be possible. The actual topology of the Universe that wraps it into a finite shape is not totally certain - in all likelihood it is spherical (as in the topology of the three-dimensional spherical surface of a four-dimensional ball) ALternatively, it could have the topology of a torus, or something more complex. It is possible that future detailed examination of the CMBR will reveal clues to the actual topology, should the Universe be spatially finite (still an open question) .
  —Cavediver

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How do you know space is finite(even if the universe has a spherical shape - which is just a hypotesis by all means now)? The material universe is expanding for sure. So if the empty space of the universe is finite, as you claim, when do we reach the boundery(and ultimately what evidence is there that proves empty space beyond the last galaxies is finite)?

The universe is not spherical but flat, according to NASA:"Recent measurements (c. 2001) by a number of ground-based and balloon-based experiments, including MAT/TOCO, Boomerang, Maxima, and DASI, have shown that the brightest spots are about 1 degree across. Thus the universe was known to be flat to within about 15% accuracy prior to the WMAP results. WMAP has confirmed this result with very high accuracy and precision. We now know that the universe is flat with only a 2% margin of error."WMAP- Shape of the UniverseEdited by Agobot, : No reason given.

This is how NASA measured that the universe is flat:http://www.astronomybuff.com/...we-know-the-universe-is-flat

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Einstein supported a finite universe. This is logical - else we would have no cnstant measurements of any kind. Space is also finite and post-universe. We know there was a beginning, aka BB, and when a single point existed - there was no space around it, but emerged later, as expansion occured.
Because a finite entity cannot contain anything infinite, all within the universe did not exist before the BB, including space, energy, matter, particles, heat, expansionism, forces, etc, etc.

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Thus there is no scientific alternative to creationism and monotheism. I have always been a firm believer that science would be the best venue to prove this.
  —IamJoseph

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The is a very very big difference between the material universe being finite(well proven) and the empty space(which so far appears to be infinite and which happens to be the topic here).
Speaking of gods, magic, voodoo, ghosts and the like in serious threads is rather childish. Edited by Agobot, : No reason given.

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So if the empty space of the universe is finite, as you claim, when do we reach the boundery
  —Agobot

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There is no boundary - if the Universe is finite it is topologically compactified into a hyper-sphere, or possibly some other more complex topological object (e.g. hyper-torus) Again, there are no *last*galaxies. All of space is filled with matter, whether the Universe is finite or infinite.
  —cavediver

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"All of space is filled with matter". How do you know that? This seems like a very bold statement for the modest stage of our development.I would be inclined to think that empty space is empty space and matter is matter. I don't really see them as one inseparable entity. Unless you mean that prior to T=0 there had been no empty space. But there is no way you could know that.
If space and matter are one inseparable entity, as you suggest, what is the matter(substance) that the universe is expanding into? Nothingness? Nothingness doesn't exist and it would seem like a form of over-simplification to think that the universe is expanding into nothingness(especially in our material world). Edited by Agobot, : No reason given.

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Further still, if space was "nothingness" or "empty" then fields (such as gravity) couldn't exist in it by definition.

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Lots of unsupported claims in this thread. What makes you think there is gravity in the empty space of the universe(beyong where we think matter ends, say 90 billion light years away from us)? How could you state that as a fact?