What if the Big Bang was just a Bounce?
. Researchers found that the expansion of the Universe with each cycle dilutes entropy sufficiently to return the Universe to its original state before the next bounce.
Kinney and his colleague, physicist Nina Stein, also of the University at Buffalo, conducted a series of calculations, and found that a cyclic Universe can't stretch endlessly back into the past. That doesn't mean that the cyclic Universe is dead in the water. The team notes that their work does not apply to physicist Roger Penrose's model of the cyclic Universe, called. According to his version of a repeating universe, each cycle expands infinitely with no period of contraction. That is pretty complex stuff, and is going to require further poking.