Is the Universe infinite or finite?

[Peso]

The universe was made 13.7 billion years ago in theory. It is also believed to be at least 93 billion light years in diameter. Is it infinite or finite?

in·fi·nite

Limitless or endless in space, extent, or size; impossible to measure or calculate: "an infinite number of stars".

[Activi-T]

I believe it to be both. An infinitely expanding finite closed system. What I mean by that is you can't go past the the 'bubble wall', or the outer edge if you were to suddenly be transported there, into the medium the universe is expanding into but the expansion of the closed system is infinite (no 'big crunch' point). That is my layman's opinion at least.[COLOR="red"]

---------- Post added 2012-12-21 at 10:02 PM ----------

I.e the stuff inside the universe is finite (energy and the likes) but the expansion (empty space/distance between things) will tend towards infinity.

[Elegiac]

I believe it to be both. An infinitely expanding finite closed system. What I mean by that is you can't go past the the 'bubble wall', or the outer edge if you were to suddenly be transported there, into the medium the universe is expanding into but the expansion of the closed system is infinite (no 'big crunch' point). That is my layman's opinion at least.[COLOR="red"]

---------- Post added 2012-12-21 at 10:02 PM ----------

I.e the stuff inside the universe is finite (energy and the likes) but the expansion (empty space/distance between things) will tend towards infinity.

Probably this. Space is infinite, the matter and energy filling it is not.

[Dezerte]

We don't know.

[SirRobin]

Everything is finite. It may be simply be to large for us to measure. So while we might perceive something as infinite, it is still actually finite.

[Sayl]

Why bother with a forum poll when you can directly consult cosmologists?

Is the universe finite or infinite? Will it recollapse or expand forever?
We don't really know in either case. Since the Big Bang happened a finite time ago (about 14 billion years), and since light travels at a finite speed, there is an unbreakable upper limit to how far away we can see in the universe. Up to the limits of the observable universe, what we observe is consistent with a uniform distribution of matter and energy that could easily extend forever. On the other hand, it might eventually turn into something very different, beyond what we can see; indeed, this might arise naturally as a result of inflation. Similarly, we can straightforwardly extrapolate the current evolution of our universe, dominated by dark energy, to predict a future in which the universe continues to expand for all time. However, the dark energy might someday change its character into something different, in which case the universe might very well collapse. So, given how little we currently understand about the nature of dark energy, we can't say anything for sure about the ultimate fate of our universe.

[Deleted]

IMO it's infinite because there will never be a away to measure it at any stage because its expanding.

[Destruktion]

For all intents and purposes, the universe is infinite. Technically, I think the universe is probably finite though because spacetime is expanding faster than we can track it we will never be able to estimate the size of the universe.

[Djuntas]

We'll I keep hearing about the sun blowing up or w/e inn was it 6 billion years...Until then

But yea, we will never know if its infinite.

[semaphore]

We don't know.

[Thage]

There's no way to know outside a currently-untestable hypothesis. Best I can figure, the universe is considered infinite, with the definition of infinite being constantly updated as the universe expands and will continue to do so until it starts contracting.

[semaphore]

Best I can figure, the universe is considered infinite, with the definition of infinite being constantly updated as the universe expands

The universe is often modelled as infinite but I'm not sure what updating infinity's definition means? Infinity would seem to be infinity.

[Deleted]

Physicist don't deal with infinity. There's nothing that you can observe to exist that is infinite. There's finite amount of particles in the universe.

[Lagwin]

Don't know why you would need a second thread about this.
It's infinite, people just focus on the known universe.
You should look at it like the entire known universe i just a dot in an infinite sea of black...the dot gets bigger slowly as the known universe expands, and there might be other dots out past out known universe.

[Thage]

The universe is often modelled as infinite but I'm not sure what updating infinity's definition means? Infinity would seem to be infinity.

Let's assume that the universe has a limit. It's so far and so rapidly advancing that you can call it the infinite universe without anyone really calling you on it. In this case, what can be considered infinite constantly grows along with the universe until it starts to collapse, at which point we know where the universe's limits are and it no longer qualifies for 'infinite.'

[semaphore]

Let's assume that the universe has a limit.

Not a reasonable assumption. You're basically talking about a finite universe. A finite universe that expands is still finite.

[Thage]

Not a reasonable assumption. You're basically talking about a finite universe. A finite universe that expands is still finite.

You hush with your logic. Alcohol's involved so this makes a lot more sense to me than it will come morning.

[Butler to Baby Sloths]

It is currently of a finite size, however its potential size is infinitely large.

[semaphore]

You hush with your logic. Alcohol's involved so this makes a lot more sense to me than it will come morning.

It is currently of a finite size, however its potential size is infinitely large.

If it's finite, that would seem to mean it will be finite... It's not like 1+1+1.....+1 can become infinite.

[Netherspark]

It depends on what you define as the universe. The term has actually become somewhat ambiguous recently.

Here's something to think about: if the universe is finite then it must have a boundry, an edge, a point where you could cross outside of the universe. But what is beyond that boundry - pure void? If so then is this void infinite?

I'm not sure if anything can ever really be infinite. Only nothing (void) can truly be infinite, but that's only because it doesn't really exist. Not to say it isn't there, but that the void simply IS non-existence iself, therefore it doesn't really exist and so is capable of being infinite.

Probably this. Space is infinite, the matter and energy filling it is not.

Actually if the universe is finite then so is what we call 'space'. Space is a part of the universe, it's not just emptyness - it is essentially an "omni-dimensional" object - space IS the universe itself. Anything outside of what we call the universe isn't space, at least not conventional space.

Space and void are two completely different things - Void cannot exist inside the universe, and space cannot exist outside of the universe.