The national bestselling author of The God Equation takes us on a thrilling journey to explore black holes and time machines, multidimensional space and the possibility that parallel universes may lay alongside our own. "A wonderful tour, with an expert guide. " --Brian Greene, New York Times bestselling author of The Elegant Universe Kaku skillfully guides us through the latest innovations in string theory and its latest iteration, M-theory, which posits that our universe may be just one in an endless multiverse, a singular bubble floating in a sea of infinite bubble universes. If M-theory is proven correct, we may perhaps finally find answer to the question, "What happened before the big bang?" This is an exciting and unforgettable introduction into the new cutting-edge theories of physics and cosmology from one of the pre-eminent voices in the field.