[JoJo the Clown]

OK, I'll buy what you said about the relationship between time and the existence of the universe, but what about the bigger point I raised? How can a singularity, which by definition, has no internal irregularity, i.e. is homogenous and uniform, transform into an irregular (non-uniform) universe? What accounts for the variation that exists post-Big Bang. It cannot be sound waves, gravity, or anything else, since whatever effects those things would have would have to be uniformly applied. No local variations would result, unless one contemplates manipulation from something other than the singularity itself. Don't you agree? If not, I would be very interested to understand why you do not?

[Darth Reagan]

By stepping in and trying to answer your question, I'm just setting myself up to be corrected by Physicist. But, my guess is that sound waves aren't uniform in the way you are thinking. Sure, the sound may have had a uniform wavelength and frequency, but by its very nature, the waves "bounce" off of the matter and energy erupting from the big bang. Picture the top of the sound wave moving up (actually rippling through) and thereby compressing matter above it (minutely, but enough). Then that more dense matter has greater gravitational pull than other matter around, and, BAM, matter starts to coalesce.

I hope I don't get beat up over this one....

[Physicist]

Don't you agree?

I do not.

If not, I would be very interested to understand why you do not?

To me, it isn't a question of how the universe, after the Big Bang, would lose its perfect uniformity, but how could possibly be maintained? The uniformity isn't stable, on any level. At the crude level of matter distribution, you have quantum fluctuations that are intrinsically random, and these are constantly being magnified exponentially by the "butterfly effect" (deterministic chaos).

But there are deeper levels of non-uniformity having to do with the structure of the vacuum that must be avoided when "growing" a universe. Early cosmological models were plagued by an unsupportable density of "flaws" in the vacuum: magnetic monopoles (analogous to point dislocations in the growing of a crystal), cosmic strings (analogous to screw dislocations), and domain walls (analogous to fractures). We do not observe any of these structures in the universe. At the level of quantum field theory, the universe is far more uniform than we would naively expect it to be.

Inflationary models solved this problem by starting with a tiny region of space containing a small number of flaws and stretching it to gigantic size; the number of flaws remains constant for topological reasons, so the density goes rapidly to something close to zero.