Paddy

I have heard on many occasions that "there is no such thing as an actual infinite", and having not been able to make an informed decision on this concept, I have generally let it go by the wayside. However, recently I have began to think about it, and it has more appeal now.

The question I have that makes me a tentative adherent to this idea is this:

If the antecedent factors that caused the universe are infinite, then why has it taken until now (or whenever the big bang was) to effectuate the existence of the universe? If we look at time (time is probably not the most appropriate word in this case, but it'll have to make do until somebnody can tell me what it is referred to pre-universe.) as being infinite, couldn't we dissect that infinite continuum at any two points and have an infinite span between them? Could we do this over and over, ad infinitum, and still have infinite spans between each point? If so, then on the earliest "dissected span", shouldn't the universe have began then. How could we arrive 'now' if the past infinite span could be broken up into sub-infinite spans, all of which could have resulted in the beginning of time?

Paddy

SlateGreySky

I want to restate your thought experimen to see if I have it right; I feel a little confused by your wording.

You seem to be saying (hypothetically) that we've got an infinite amount of time separating event A from event B. If we put event C, say, halfway between A and B, there is still an infinite amount of time between A and C, even though that's just half the distance from A to B. Just so for event D, placed halfway between A and C, and so on ad infinitum.

That's solid enough, but I'm not sure where your thought experiment takes you from there. It seems like you're asking why the big bang happened when it did, as opposed to sometime before then. As far as I know, most cosmologists (and philosophers) resist the notion that there was such a thing as 'time' before the beginning of the universe. To have time, you must have change, and to have change, you must have events. Since nobody is positing any events which took place before the beginning of the universe, there can't have been any time at which the universe did or did not begin.

Does this approximate the issue with which you're dealing? I think it's an interesting topic, but I'm afraid I've mistaken you.

xoc

The question is, why would a segmented infinite be infinite, or how could it? If it is segmented, it is a finite segment. If we define the infinity of an object as it's endlessness, to make "ends" of it(as is) is to make it finite, but finding the finite in the infinite does not make the finite infinite. The infinite "line" is still comprised of endless segments of arbitrary length.

<-----------------------0--------------------0------------------------->


The line is infinite, the point between the two is of a finite length(line segment). If the Universe can be said to have a "Beginning":


0-----------------------0------------------------0------------------------->

Is this considerable as a uni-directional "infinite?" If Time has a beginning but no End, could it be ascribed as infinite in the forward direction but not so in the backward direction(and taking note that the backward direction may not have any possibility in reality, ie. there is no-back-in-Time in reality(empircally observed), say, how do we define whether or not there is a finite or infinite status back-in-time?

Not understanding the beginning, perhaps this is best:

?--------------------0----------------------------0------------------------->

or more honestly (not knowing if Time has an end)

?-----------------------0---------------------0---------------------------?

maybe the most honest:
?????????????????????????????????????????????????? ???????
(last one is a joke perhaps)