@Bracewell,
It seems we know about galaxies that are 13.5 light years distant, which if we take the best possible rate for the transmission of information then it makes the big bang not less than 13.5 billion years old. So, can we assume that the cosmos is contained in a volume with a diameter of 27 billion light years? Well, maybe. However, if it is assumed that in that far away galaxy there is a telescope looking at us then is it reasonable to expect that the view thru that telescope would be the same as our view? And again, if we turned our telescope to look in the opposite direction might we not possibly see another similar situation? Hopefully, you are now ahead of me and you can see there is a potential at each distant telescope to increase the diameter of the cosmos by an infinite amount but in jumps of 13.5 billion light years. Now, is that not an awful lot of potential volume to be considered as closed?
The above was my post on this thread (13th) but since then I've had a further blunderment in that I can think of another another possiblity.
Lets say that our telescope is position A and primitive galaxies can be seen at an extreme distance at position B. Our telescope is then turned to look in the opposite direction and again primitive galaxies are observed at an extreme position C.
So, what can reasonably be assumed -
Does the telescope at B have the same view of A as A has of B?
Similarly, does the telescope at C have the same view of A as A has of C?
Now crucially. does B have the same view of C as A has of B and C, and does C have the same view of B as A has of B and C?
The quick answer is to say no, because the distance is doubled and the universe is not old enough for the light to have travelled that far. This is a real time, now question that cannot involve inflation.
I think it is reasonable to assume that the views at B and C would be no different to the view at A, which would mean that light would have to travel at a much faster speed but that would be OK because time would stretch to allow it.
Ok, so playing with this, then in order for the unverse to look the same in every direction and from every view point there must be conditions where time virtually slows to a stop to allow light to travel from every view point. The boundry of the universe would then be dependent on the rate of time.
I hope you are now suitably boggled because I am.