- #106
fencewalker
- 17
- 1
the way i see it, the space between the galaxies is expanding within the universe. they are moving in relationship to each other. space itself doesn't change, just the distances between the objects within space.
If galaxies are moving away from each other which is proven and they are expanding into 'something' the furthest galaxies should be feeling this ultimate wall at some point? Well many theorists might disagree on the single universe idea but that is not the idea of this discussion.phinds said:Absolutely not. (1) As jbriggs said, there is no need for anything to expand "into", and (2) IF there is a multiverse (which I personally do not believe) there is no theory or evidence that different universes could be in casual contact with each other.
So this this realm the universe is infinite? How can this be proven?fencewalker said:the way i see it, the space between the galaxies is expanding within the universe. they are moving in relationship to each other. space itself doesn't change, just the distances between the objects within space.
No they are not. You need to read some basic cosmology. I recommend Googling "metric expansion" as a start.infinitebubble said:If galaxies are moving away from each other which is proven and they are expanding into 'something' the furthest galaxies should be feeling this ultimate wall at some point? Well many theorists might disagree on the single universe idea but that is not the idea of this discussion.
It is NOT known that the universe is infinite. The consensus these days seems to be that it is but there is no proof. Regardless of whether it is infinite or finite but unbounded, it is not moving "into" anything.infinitebubble said:So this this realm the universe is infinite? How can this be proven?
I completely agree with this. The balloon analogy is aimed showing the possibility of isotopic recession with no center. It happens to use a finite surface. You cannot meaningfully pretend it is infinite.russ_watters said:I'm aware.No, I'm aware it isn't a sphere.
Agreed, but that isn't what the analogy says: the analogy considers only the 2d surface. However:
That, again, is my problem: picking a clearly and exclusively finite object and calling it infinite is.
I agree completely. As I state in the referenced Insights article, the analogy is not intended to comment on the size of the universe.PAllen said:I completely agree with this. The balloon analogy is aimed showing the possibility of isotopic recession with no center. It happens to use a finite surface. You cannot meaningfully pretend it is infinite.
The goal is that many people have trouble picturing expansion everywhere in something already infinite. Marbles don't help this intuition problem - they just ask how all the marbles can make room for each other over an infinite surface. You can include marbles in my model. Cut the infinite grid of marbles into sections. In each one, move the marbles further apart. Now reassemble. I think breaking it into these steps make visualization easier for some people.fencewalker said:why cut up space itself, that is not what is moving. drop some marbles on ur infinite plane and watch them expand away from each other. the marbles are galaxies in ur infinite plane. as i c it...