Thread: ?

Hi guys, I've been reading quite a bit about the 'Big Bang' and of course I can see how this could be feasable. But I still have a BIG ? about the theory.

If indeed the universe began with a Big Bang and as a consequence the universe is still moving away from the source of the Big Bang, what is this universe expanding into ? Does EVERYTHING move away from the Big Bang centre to accomodate the resulting universe ?

BARCUD

Everything is the "source" of the big bang, and the big bang "centre" is now everywhere. There was no space outside the big bang, and all space that exists now was inside the big bang.

I hope this incoherent explanation is somehow clear

Thanks for the reply.

This is my 3rd attempt at replying to you but for some reason none of them uploaded ! So here goes again.

Okay, after the big bang no space was needed to expand into as the big bang is the expansion. BUT, what if the expansion slows down and grinds to a halt and perhaps the expansion reverses ? Would the reverse leave behind a space that was once filled by the big bang ? I'm picturing a ballon being blown up BUT having no space to expand into !

any thoughts ?

BARCUD

Originally Posted by BARCUD

Thanks for the reply.

This is my 3rd attempt at replying to you but for some reason none of them uploaded ! So here goes again.

Okay, after the big bang no space was needed to expand into as the big bang is the expansion. BUT, what if the expansion slows down and grinds to a halt and perhaps the expansion reverses ? Would the reverse leave behind a space that was once filled by the big bang ? I'm picturing a ballon being blown up BUT having no space to expand into !

any thoughts ?

BARCUD

The problem that you are having is the assumption that the universe is contained in something else.

Rather by definition, the universe is all that there is, all that can affect us or affect anything that can affect us or affect that .....

If one accepts general relativity then the universe is a 4-manifold with some additional structure. That entity, called space-time describes the causal structure and physics of the universe, It is not contained in anything else, or at least not anything that can affect it. To expand it does require any space into which it expands and if it contracts it does not leave space behind.

To get your head around this you need the idea of an intrinsic manifold, or just the more simple notion of a universal set from elementary set theory in the sense of Venn diagrams. The universe is as big as it gets, the whole sheet of paper in the case of Venn diagrams that you have dealt with in a school lesson on sets.