Johnny Galecki plays a character with a Ph.D. in The Big Bang Theory.
 In the latter model the Big Bang was preceded by a Big Crunch and the universe cycles from one process to the other
=== PreBig Bang cosmology ===The Big Bang explains the evolution of the universe from a starting density and temperature that is well beyond humanity's capability to replicate, so extrapolations to the most extreme conditions and earliest times are necessarily more speculative

