Dispelling infinite universes

[Royston]

This may be a very silly and simple to answer question, but it's kind of bugging me.

 

When I was 12 I thought of the idea of infinite universes to try and get round the whole boundary of the universe problem. I found out later on in life I wasn't the only one that thought this could be possible.

 

However supposing the big bang was at the start of the universe, and for the possibility of infinite universes being created, wouldn't the rate of expansion have to be infinite ? If the rate of expansion is infinite, how would matter have time to cool and create uniformed bodies such as planets ? Wouldn't the highly disordered state at the beginning of the universe stay in that state due to the infinite rate of expansion.

 

If the rate of expansion isn't infinite, does this mean there is only one universe and the boundaries can be explained in some other way, maybe a vacuum (that's just an example of the top of my head).

 

I'm probably going to get a grilling for posting this, so be gentle I've got a screaming hangover.

[Nicholas]

Right on snail.

 

Einstein dealt with the boundary problem; the space-no space

problem; by introducing his gravity as a cosmology. If gravity

curves space everywhere then the whole universe can curve

back on itself. This is his finite but unbounded universe.

 

Stephen Hawking is the same way.

[Royston]

Time to brush up on GR.

[Ewen]

It would be like a balloon: expanding and appearing to be getting expand, but not having a boundary. What's north of the north pole?

[danny8522003]

When I was 12 I thought of the idea of infinite universes to try and get round the whole boundary of the universe problem. I found out later on in life I wasn't the only one that thought this could be possible.

I had that same revelation, i hate thinking of something only to find someone else thought of it first .. nevermind.

 

I understand the point your making, but why does the rate of expansion need to be infinite?

 

The way i see it, every decision spawns a new universe seperate to our own, like taking a turn in a road. Each of these universes is completely independant of each other (unless considering time travel paradoxes, but that's seperate) and therefore the rate of expansion for each universe would be independant of the other universes. I.e. just because this universe is expanding at a certain rate, what's to say a parallel one isnt contracting because of a different quantum "choice" made earlier in time?

[NeonBlack]

Once you get to the north pole there is no more north.

The finite bounded universe I believe is more like going east (or west).

[danny8522003]

I believe a universe in a shape you are describing is called a hypersphere (a 4D sphere), not that you could even begin to imagine what one looked like unless you do away with one of the spacial dimensions in your mind.