Is the universe infinite or finite?

It's high time we started with these kinds of discussions again on LPF. When this section was first created we had high level discussions on these topics.

Discuss. Please don't just post Google answers, try to discuss it here.


Is the universe infinite or finite?

Yes.






:na:

pullbangdead said:

Yes.






:na:

Click to expand...

Please try again later :evil:

I think finite. However there might be something beyond the universe that is infinite - in a way.

The was I see it, is this:

The universe is finite in the cosmic scale.

It is however infinite on the human perception scale.

The reason being that like any other explosion it is expanding, at what I believe to be the speed of light (0.02), therefore even if, we were to manufacture a vehicle that would approach the speed of light and send it on a course for the "end of the universe", it would theoretically never reach the end. (taking aside the obvious millennia it would take to reach anywhere, even at that speed)

However, we must also take into account that our universe could be one which expands infinitely until it basically "freezes over".

Or, it could be one which when the "expansion" stops, the force of gravity is strong enough to pull everything back together, in time creating the conditions for a new Big Bang, in effect a hard restart

When talking about the size of the universe, we usually talk about the size of the visible universe, which is defined as the speed of light times the age of the universe. (*suppressing urge to look the number up on the internet*)

Nothing concrete is known about the size of anything beyond that, however there are theories (string theories, of which there are like 5 or so), which state that all dimensions (there are 10 or 11 dimensions, depending on which theory you take) started out very small, but only a few started to expand. These dimensions are like loops which curl back on themselves (like the surface of the earth in 2 dimensions). After the first dimension grew, there was enough probability for another dimension to expand (for the exact mechanism of this probability, read Brian Greene's The Elegant Universe). After the fourth dimension (third space dimension) expanded, the probability dropped dramatically, preventing any other dimensions to expand, hence we observe 3 space dimensions and one time dimension. The remaining dimensions remain curled up in tiny manifolds (a manifold is an n-dimensional folded space that locally looks like flat euclidean space, like the ground you're standing on looks flat rather than convex) called calabi-yau space. If these theories are right then it implies that space is inherently finite.

Just imagine a universe where four space dimensions expanded... Then life might have evolved, which eventually call themselves 'human' and they wouldn't know better than being 4D

What a great topic Niko.

For me it's difficult to sway one way or the other.

does to vast space that may exist beyond all planets, stars, asteroids and matter count??

If it is finite, then what lies beyond?? a big "wall"?? if so then what exactly would be on the "other side" of that??

In other words if the universe is finite the what exactly makes it finite, and what exactly would be "beyond that"

This is one of those things many people have pondered forever.

As ZomB alluded to above, the answer to this question is 100% dependent on how you define "tne universe." :wtf:

If "the universe" is "everything", then it by very definition infinite. Everything would include anything beyond our understanding or perception. Even if it "loops back onto itself" as has been postulated, it would still be by definition infinite.

If however, "the universe" only refers to this particular "bubble" then it would have identifiable limits and thusly be finite. Any other "parallel's" or "multi-'s" would be beyond THIS universe :san:

The universe is finite or infinite based on our description of it. :thinking:

Words = meaningless constructs that define reality -- Welcome to the world of the dialectic

Peace,
dave

The question is unanswerable empirically.

One upon a time, in this universe, inside an infinitesimal solar system in a small spiral galaxy, on a nearly imperceptible blue planet, on a planet-wide computer network, on a forum called laserpointerforums.com, a guy called niko started a thread about human perception of the universe IN THE WRONG SECTION...

this section is for science pertaining to lasers, so I believe this should be in the "other" section...:na:

ElektroFreak said:

One upon a time, in this universe, inside an infinitesimal solar system in a small spiral galaxy, on a nearly imperceptible blue planet, on a planet-wide computer network, on a forum called laserpointerforums.com, a guy called niko started a thread about human perception of the universe IN THE WRONG SECTION...

this section is for science pertaining to lasers, so I believe this should be in the "other" section...:na:

Click to expand...

:banned: LOL! I didn't even notice :banned:

Curse you , recent posts list! :gun:

Peace,
dave

Finite. Although trying to reach "an end" by going in one direction wouldn't succeed. I believe the universe is much more than "space", although I really can't say what would happen if you traveled until something happened xD

I have severe problems when trying to put in words something that I don't understand at all myself xD

All in all, there must be a finite amount of energy out there!

PD: That's why I love this forum so much. Post this same thing anywhere else and people will laugh at you or answer lame things. It's incredible that a laser pointer forum has such a "high" intellectual level

ElektroFreak said:

One upon a time, in this universe, inside an infinitesimal solar system in a small spiral galaxy, on a nearly imperceptible blue planet, on a planet-wide computer network, on a forum called laserpointerforums.com, a guy called niko started a thread about human perception of the universe IN THE WRONG SECTION...

this section is for science pertaining to lasers, so I believe this should be in the "other" section...:na:

Click to expand...

Wrong, the purpose of this section was to discuss topics just like this.

How do I know that? Because I proposed it back in 2007-2008 when threads that discussed spirituality/science between dave, ace82, PBD and me were emerging

As we stopped creating such threads, the discussions stopped as well and in consequence newer members only see this section as one to discuss science of lasers only, which indeed is was not the original purpose of its creation


In conclusion, carry on






This is my loop, which makes me angry because I can't reach anywhere:

1) If the universe isn't infinite, then it's inside something bigger, or it's on the side of something else.

2) If we were to reach an edge or end of it, then we could somehow "break the wall" and see what's on the other side.

3) But according to Physics there's no way space is infinite, so it must be finite, which leads me to 1)...

EDIT: I also believe it has something to do with it being a 4 dimensional space. The ant in a balloon analogy doesn't do it for me, because the ant is walking on the very edge of the universe then, and it could somehow break it to see the "outer" world/space.

nikokapo said:

Wrong, the purpose of this section was to discuss topics just like this.

How do I know that? Because I proposed it back in 2007-2008 when threads that discussed spirituality/science between dave, ace82, PBD and me were emerging

As we stopped creating such threads, the discussions stopped as well and in consequence newer members only see this section as one to discuss science of lasers only, which indeed is was not the original purpose of its creation


In conclusion, carry on

Click to expand...

Appeal to tradition = logical fallacy

nikokapo said:

This is my loop, which makes me angry because I can't reach anywhere:

1) If the universe isn't infinite, then it's inside something bigger, or it's on the side of something else.

2) If we were to reach an edge or end of it, then we could somehow "break the wall" and see what's on the other side.

3) But according to Physics there's no way space is infinite, so it must be finite, which leads me to 1)...

EDIT: I also believe it has something to do with it being a 4 dimensional space. The ant in a balloon analogy doesn't do it for me, because the ant is walking on the very edge of the universe then, and it could somehow break it to see the "outer" world/space.

Click to expand...

[echo] Welcome to the world of the dialectic[/echo]

Peace,
dave

@Niko: As I said, I think we're wrong when thinking in the Universe as a "3D space".

nikokapo said:

Wrong, the purpose of this section was to discuss topics just like this.

How do I know that? Because I proposed it back in 2007-2008 when threads that discussed spirituality/science between dave, ace82, PBD and me were emerging

Click to expand...

then someone needs to change the name of this section, because it clearly states "Discuss physics, metaphysics and science applied to lasers." I don't really care, though.. I only brought it up to be silly.