In fact, if the Universe was high in entropy at the Big Bang, it couldn't exist as we know it.
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."Our proof shows in general that any cyclic model which removes entropy by expansion must have a beginning.".
The team notes that their work does not apply to physicist Roger Penrose's model of the cyclic Universe, called conformal cyclic cosmology. According to his version of a repeating universe, each cycle expands infinitely with no period of contraction.