The Big Bang
What happened before the big bang?
Discussion of the early universe inevitably bring up the question
"What happened before the big bang?" The answer is simply "We don't
know." As one goes back in time, the material in the universe becomes
denser and denser as well as hotter and hotter. Eventually, one
reaches the point at which things are so dense and so hot that our
current understanding of the laws of physics are unable to make
predictions about what occurs. What is worse, at sufficiently high
temperatures and densities, the two major theories which we think
describe the universe at this stage, general relativity and quantum
mechanics begin to actually contradict each other.
In order to know what happened "before the big bang" or even to know
if that question makes sense requires advances in our understanding of
high energy physics and will remain open until this understanding is
reached.
Joseph Wang (joe@athena.mit.edu) 1993-09-15