Q: Briefly describe what is big bang theory. (CSS-2011)
The Big Bang
Once it was understood that the Universe had a beginning, scientists began to ask “how did it come into existence, and what existed before it?”
Most scientists now believe that the answer to the first part of the question is that the Universe sprang into existence from a singularity — a term physicists use to describe regions of space that defy the laws of physics. We know very little about singularities, but we believe that others probably exist in the cores of black holes.