How do we deal with the concept on infinity? It seems to linger about the limits of everything. For me, this is the biggest problem in some sense. I wanted to ask the question in the context of the the multiverse. This is a big trend now in physics and cosmology and usually gets lots of people excited Since we have now started saying that our Universe might not be the only one, haven't we simply pushed up the problem into a higher category. Let's just imagine that the Universe is a finite soap bubble and so as in common analogy, there are many bubbles/universes in the multiverse but if I ask whether all these bubbles are in finite bath tub? then the answer is equivalent to saying that our single Universe is infinite. Suppose we did start saying that someday that our Multiverse is also a finite one, a really big bubble with lots of bubbles in it which share some common properties (superset, subset), then there would suddenly be the multi-multi verse! So really at this point, aren't we just pushing infinity higher and higher to avoid dealing with it? Now suppose we take the brane theory and there are all these parallel branes stacked and they touch every once in a while creating big bangs, well these branes are supposed to stretch infinitely so where would they touch? Not to mention, there is an infinite stack of these membranes. Then there is the black hole-white hole theory. Ok, some our Universe might be in a black hole opening into another realm the opposite side of which is a white hole and we see it as the big bang. So its like branching since we know lots of black holes are there in our Universe. Where then does the first black hole com from? Of course, there are many theories but this infinity thing runs as a common thread. For me, dealing with infinity is the same as studying a black hole. The gravitational singularity comes into play right at the start of our Universe and we encounter the same thing at the center of black holes. Why aren't we all just working on figuring out what happens at singularities. At this point we're pretty sure that black holes DO exist but how is infinite density possible/zero volume possible? What is its nature? Can it be described definitely rather than in infinite terms? if something falls towards a singularity, what happens to it? does it emerge elsewhere in another form? We we could know, wouldn't we automatically know how things can come out of singularities like out Universe? Is there a conceivable limit to what we can know and answer quantitatively and qualitatively? Also, just a side question about our Universe itself? Isn't it supposed to have finite matter/energy? and there is a definite rate of expansion so it must be finite in the sense that it has only stretched so much? also, it has a definite age so it seems like that itself must impose a limit/boundary. I'm not hinting towards the sort of thing where I then ask what exists outside this boundary? I've seen posts before that asked this question and it was frowned upon but is there a distance from our point of view in every direction where the Universe has still not expanded to? The CMBR should not exist at a certain point or rather, there should be a point where there is no temperature.