Space and time form the very fabric of the cosmos. Yet they remain among the most mysterious of concepts. Is space an entity? Why does time have a direction? Could the universe exist without space and time? Can we travel to the past? The author uses these questions to guide us toward modern science's new and deeper understanding of the universe. From Newton's unchanging realm in which space and time are absolute, to Einstein's fluid conception of spacetime, to quantum mechanics' entangled arena where vastly distant objects can bridge their spatial separation to instantaneously coordinate their behavior or even undergo teleportation, Greene reveals our world to be very different from what common experience leads us to believe. Focusing on the enigma of time, Greene establishes that nothing in the laws of physics insists that it run in any particular direction and that "time's arrow" is a relic of the universe's condition at the moment of the big bang. And in explaining the big bang itself, Green shows how recent cutting-edge developments in super-string and M-theory may reconcile the behavior of everything from the smallest particle to the largest black hole. This startling vision culminates in the vibrant eleven-dimensional "multiverse," pulsating with ever-changing textures, where space and time themselves may dissolve into subtler, more fundamental entities.