[xelasnave]

What a wonderful discussion.

Robert you raise an interesting aspect about the universe being infinite or not.

The big bang has a feature I feel folk overlook when they suggest that it may be infinite.

The difficulty in my view must be that if we start with a finite object, and it would seem that the big bang starts with a finite object, we can not grow that object to infinity.

I think the theory of inflation basically suggest a rapid doubling of size and I suggest that no matter how many times you double the size you can never reach infinity.

As I understand the term it is a situation where adding subtracting or to multiply can not alter infinity.

I think the big bang can suggest the universe is very big but its premise of an intial finite state must preclude the big bang universe ever being infinite.

My understanding of the size of the observable universe is that it is approximately 90 billion light years in diameter..If I can find authority I shall post same.

Raymo

I also am not sure about the prohibitions that may be found in the Standard Model however I think one must remember that the suggestion that the Universe may have come from nothing has no basis in so far as the Big Bang Theory only takes us to a time a short time after "the big bang" and at that time the theory deals with a hot dense something often refferred to as a singularity but a something nevertheless.

Why folk jump from there to speculating that what ever it was that was hot and dense came from nothing I really dont know..

I think to arrive at that conclusion is driven by a need with humans to identify a creation point...the big bang certainly does not do that but certainly given the need or expectation that humans hold that there is a begining one can understand speculation will go that way.

But we have no science model to suggest something came from nothing.

And really even those folk who speculate upon where the "stuff" came from invoke quantum fluctuation which is something and certainly not a condition where we could reasonably say " well this condition is nothing."

As to accepting anything is possible I suggest the concept of inflation goes way beyond anything we can observe and perhaps the concept is beyond comprehension...but as I have said, for myself I find the proposition that the universe could grow from the size of a basket ball to a diameter of over 90 billion light years in a zillionth of a zillionth of a zillionth of a second...which for all reasonable analysis one can consider to be instantaneous...a period so short what else could you call it but instant??? ...to be highly unlikely particularly as there is no evidence at all...zip.

Now irrespective of what this initial stuff was that inflated I dont know how one can accept that such could be remotely possible ...it is even beyond god like...and yet no one seems to stop and say "hang on this is the most extrodinary claim that has ever been made in all of history should I accept it on the basis that someone has created this view by math alone with absolutely not one piece of observational evidence."


My concern is that such an acceptance has prevented any further developement of cosmology.

The idea was needed to fix the sameness problem...I expect hastely and in a panic for the problem as perceived threatened to bring the big bang theory down...and I get the impression the theory of inflation was presented and accepted with sighs of relief and the matter never visited again.

I think the sameness problem could be looked at differently..perhaps rather than requiring an external cause confinned to a small region there could be an inherent quality of matter that causes it to be the same as other matter even if that other matter is at the opposite end of the universe...and could not such and approach be more reasonable than requiring an instant growth of the Universe?

Personally I favour a static universe as did DrA and am inclinded to think a steady stste universe is probably more likely..the steady state has its problems granted but nothing like needing the theory of inflation.

But the proponents guard the theory because in my view it gives the thinking man the answer he wants (and what all humans through out time have wanted) and that is a point of creation.. .which ironically the bbt actually does not do...but it is a short leap (a quantum leap☺) to find creation if not god.

I dont think there could be such a point oppting for the belief there has always been something...meaning no start, no end, no top sides or bottom...and as you ponder that consider the saying "it is a wise man who can imagine a stick without ends"☺.

Hi Ryan
Although the universe is thought to be 13.5 billion years old that does not mean its diameter is 27 billion years...why? well one must include expansion since the inflation...the expansion is not limited by the speed of light you see☺ as it is space that is expanding and as such not confinned to loght speed...and here I note inflation and expansion are best thought of as two greatly different eras...or so I believe.

I will try and find authority for the size of the observable universe but I would encourage you to search as it will be so much more satisfying for you to work it out.

I hope our discussion can continue as it is an intetesting matter and somewhat tied to what we do...although I must admit I still regard cosmology as a sport where no particular view can be said to be certain...
Alex