Time Before Time

[Orstio]

http://sciencenow.sciencemag.org/cgi/content/full/2007/705/3?rss=1

A cosmologist has created a mathematical model that he says shows space-time, contrary to common wisdom, did not begin with the Big Bang. Instead, the model suggests a universe pretty much like the one we live in today existed before the event, except it was contracting instead of expanding. If ever proven, the idea could force a complete rethinking of the origins of the cosmos and perhaps even open a doorway to an endless future.
The Big Bang--the sudden and extremely rapid expansion of space-time that began 13.7 billion years ago--is generally accepted among scientists as the beginning of the universe. However, they have long puzzled over a paradox that the event caused in the mathematical calculations of Einstein's Theory of General Relativity. At the moment of the Big Bang, everything was thought to be crammed into a singularity--a space with no dimensions--that also contained infinite density. Einstein couldn't explain how such a state could give rise to a universe of finite density and possibly finite dimensions. Theoretical physicist Sean Carroll of the California Institute of Technology in Pasadena put it more succinctly: "Everyone's calculations show the universe started from a singularity," he says, "but no one believes it."

[kanzure]

It has been my understanding that the common conception of the Big Bang being the beginning of spacetime is entirely wrong and contrary to the actual theories published in scientific journals. From my queries over at arXiv.org, it looks like people do not actually think the Big Bang was the origin of the universe.

- Bryan

[Orstio]

There is certainly a lot of specualtion about it.  The book The Big Bang Never Happened is an interesting read.  I don't have it with me now, but I seem to recall the claim that if you removed every bit of space between every proton, electron, and neutron in the visible universe (that which we have already seen), it could not be condensed any smaller than a ball several light years across.  Keep in mind that it would not only be impossible to do this, but that bringing so much mass together would also warp space and time in very unknown ways, so I don't think any of it can really be ascertained.