Yeah, but what happened before the Big Bang? 
Supermassive blackhole collision in another universe! 
The word “where”, just like the word “when” is meaningless in the context. Everything - all of space - was in that singularity; the singularity wasn’t located somewhere in space - rather all of space was located inside it.
So it occurred everywhere, by definition. Every part of the universe was in that infinitessimally small point. Then that point expanded.
Regarding the expansion of space now - everything isn’t moving away from a single point. Everything is moving away from everything else. Wherever you stand in the universe, everything is moving away from you.
Bit of a nitpick, but does it make sense to talk about space being “inside” the singularity? If there is an “inside”, then there is an “outside”.
Yeah. But I don’t think there are words which actually work. I imagine physics theorists could point us towards equations which describe it, but I don’t myself know of the right words.
I think it’s best to just say: the singularity is space-time. The best analogy I’ve seen, as already mentioned, is the 2D analogue of the surface of the balloon.
Well, now that I’m a bit more sober…
Actually, a singularity simply is a term that means ‘no one knows’. There are various theories about what the universe may have looked like before the big bang, but the problem is that (at least from my limited understanding) the physics and equations all break down before the big bang started, so there is nothing to actually describe what was there ‘before’.
While my OP was confused, I actually DO understand that there was no space or anything else for the universe to expand into…that in fact it was space/time itself that did the expanding and continues to do so. I’m not sure what I was getting at exactly with my own question (which should tell you a bit about my state last night), so I’ll just say that it was a silly question in retrospect and that I do understand the explanations, at least to the extent I’m capable of doing so without understanding the math involved.
Well, except the parts that aren’t. I understand that our own galaxy is destined to smash into another in a mere couple of billion years (Andromeda?).
Anyway, I want to thank everyone for the explanations and the patience with my silly question. It’s appreciated. Next time I do something this incredibly silly I’d appreciate it if someone would ask ‘XT? Are you drinking again??’…
-XT
So, didja beat up a Cosmos or two this time?
Sadly, no. I’m still recovering from my last beating. But thanks for asking.
-XT
Only on a very local scale (and that is, beleive it or not, a very lcoal scale compared to the universe) If I walk towards you, I’m obviously not moving away from you.
But on a large (universal) scale, everything’s moving away from everything. But some thinkgs may be moving closer to each other on a local scale.
Nitpick: We know that we’re getting closer to each other, but that doesn’t necessarily imply that we’re going to collide, and in fact we probably won’t. It’s more likely that we’ll just pass each other and then start moving further away again, starting another orbit.
I think it does make some sense to talk about “inside” vs “outside” though those might not be the best terms to use. As I understand it, even the emptiest space still has energy associated with it. So, the mere fact that there is a there takes some degree of structure/energy/whatever to make it exist.
Thus, you can distinguish between space (that which is “inside”) and not-space (that which is “outside”). But, of course, you can’t see, detect, measure, etc. the not-space because it is not.
Colibri said:
This is the part I have trouble with. I accept that there is no location in space that the Big Bang occurred, that the universe itself as a whole is the Big Bang. But what bugs me is the external question.
Cosmologists argue there is no space outside the universe, so the universe is not expanding into anything. But then they say that at the moment of the Big Bang, the universe popped into existence as a tiny, microscopic spot of energy. So where was that spot?
If the universe is expanding, it must be expanding into something. That something isn’t the universe, but what is it?
Similarly, cosmologists will simultaneously state that the Big Bang was the begining of time, so it makes no sense to talk about “before the Big Bang”, and yet then they will speculate that our universe was born out of a cyclical pattern of bangs and crunches, or that there are other “universes” out there. But if there is a cyclical pattern or other alternates, then there is an out there and a before.
I can accept an answer “we don’t know” and “it is useless to speculate”, but I have difficulty accepting the answer “there is no there there” and “there is no before”. Cosmologists aren’t even self-consistent, no wonder the public thinks they’re full of it.
Different cosmological theories are not consistent with each other, but each theory (or at least, so far as we know, each theory that’s taken at all seriously) is consistent within itself. The fact that there are still competing theories is a sign that we don’t know everything yet, but I don’t think you’ll find a cosmologist who claims that we do.
Irishman, the idea that the Big Bang is cyclical has been pretty well disproven at this point. Everything we know says that it is not cyclical. (Which is not to say that they won’t discover something new in 10 years and change their minds).
The fact that we can think about the universe expanding into something surrounding it really doesn’t make it true. You just have to come to a point of understanding that a chunk of deep outer space is still a thing. It may be devoid of planets, dust, atoms and even photons, but it is brimming with virtual particles that pop in and out of existence because technically they never did exist. Furthermore, it has dimensions - height, width, depth and time.
If you want to think of something outside, I think you have to realize that it isn’t even empty space. Not only is nothing in it, there are no virtual particles. It has no height, width or depth and no time. There are no laws of physics that govern it.
Imagine that you went to an art gallery and saw a blank sheet of paper hanging on a blank wall. You could say “There’s nothing there,” when in fact there is a piece of paper. Imagine the artist comes up to you and says “You can’t see it, but the real art was drawn outside the paper.” You’d call him insane, right? There’s no way to draw anything outside the page because there’s not even something there to draw on.
Partly these are language issues. We can’t imagine, and therefore haven’t developed the language to describe what we mean - so we use words like “into something” and “outside” and so forth. But they’re just words.
The only way it can be described is via lots of horrible complicated equations. The best we can do to describe the meaning of those equations is create crude analogies, etc. - but that’s all they are: analogies described with limited language. So it’s no wonder that fokls have difficulty with the concepts, because we simply can’t imagine or verbalize it.
But we can write equations which describe our theories. And then some very clever people attempt to sumamrise those equations into layman’s terms using analogies and words like “expand into” and “inside” and “before” and so forth, and of course those anaologies fail to accurately describe the equations. But they come close enough that we can attempt to discuss the vague concepts in very general terms - and end up with threads like this. 
Chronos said:
I’m not talking about the theories themselves, I’m talking about the meta topic, the way cosmologists talk about the topic to people. When people ask “What is the universe expanding into”, the cosmologists explain “Nothing. The universe is everything.” But then when trying to discuss the ultimate beginning and ending, those same cosmologists will bring up either cyclic universal bangs and crunches, or that there are other “universes” with different natural laws, or whatever. That is inconsistent to me.
dracoi said:
Tell that to the physicist I heard repeating it just the other day (Discovery Channel program about the Big Bang called, IIRC, “The Universe”).
I know, the universe appears to be expanding, and the rate of expansion increasing. I was puzzled, too, but that guy still said it like it was a current possibility.
Candyman74 said:
Fair enough. The words we use have inherent assumptions based upon the context in which we live and experience the world, so the concepts we are trying to discuss are outside that framework, and thus the words don’t exist. Still makes it durned confusing.
Its inconsistent because we don’t have the language to talk about it in a self-consistent way. Current cosmological theory [at the bleeding edge which probably hasn’t made it into pop culture/science yet, (and yes, The Discovery Channel is pop science)], suggests that we’re not in a cyclic universe but a universe that’s expanding at an accelerating rate. However, we have precisely no way of knowing about other universes or indeed what, if anything is “outside”, our own – we just do not have the means to know. We can describe these cosmologies with mathematics in a consistent way, but heck, I know that even I probably wouldn’t understand said equations without getting a serious headache (and I deal with observational cosmology as the day job). Putting it into language that Joe Average understands is seriously difficult.
Not the same cosmologists.
And there are some current braneworld models which do include cyclical bangs, but I (and I suspect, most cosmologists) would maintain that they needlessly multiply entities.
When we were kids, my sister and I decided somehow that the space outside the universe is filled with cheese sandwiches, or at least that the universe is surrounded by cheese sandwiches. I have no idea where we came up with that from.