The Big Crunch Theory

The Big Crunch theory is a 'death and rebirth' theory that shoots off from the Big Bang Theory.  In the Big Crunch, our Universe moves in a cycle of sorts.  The cycle begins with The Big Bang(a superheated, superdense egg expanding to over a billion times its original size), and ending with the Big Crunch, which is the Universe expanding so much that, like a rubber band, it snaps back an gets small again.  How exactly is this a cycle?  The Big Bang and the Big Crunch repeat constantly, shrinking and expanding an infinite number of times.  There is not much evidence to dispute this theory, apart from the fat that we are assuming there would be enough gravity to pull the Universe back int that teeny tiny ball.