Opposite the Big Bang there is something called a big crunch, if a Universe does not have enough energy or power to keep expanding it recedes back to
its central point where the universe is 'consumed' by mega blackholes. Theoretically speaking this could trigger off the creation of a new Universe,
and this chain of Birth, destruction, birth, desctruction could be infintessimal so the Universe does not have a beginning.
Our Universe is actually continually expanding so it won't succumb to the Big Crunch, this Universe will exist till everything burns out and all
energy goes 'cold' to a state where it slows down.
Another way of thinking of the creation of the Universe is if nothing existed beforehand, no time. In a state of 'no time' everything
at once because there is an infintite amount of time for it to occur, so the creation of mass energy is probable, and the conditions of the Earth
would always turn out to be perfect for life as there would be no chance of us experiencing a bad one because we would never of existed to see a bad
universe (that last statement sort of answers the Creationists view on how a perfect Universe came into existence. Did it happen by chance? yes!)
I should have the links to the info in this topic ssomewhere, I'll post them if I find them. I hope this sort of made sense and was readable
[Edited on 2-7-2003 by MrEisenhower]