The bestselling author of The Elegant Universe and The Fabric of the Cosmos tackles perhaps the most mind-bending question in modern physics and cosmology: Is our universe the only universe?\There was a time when "universe" meant all there is. Everything. Yet, a number of theories are converging on the possibility that our universe may be but one among many parallel universes populating a vast multiverse. Here, Briane Greene, one of our foremost physicists and science writers, takes us on a breathtaking journey to a multiverse comprising an endless series of big bangs, a multiverse with duplicates of every one of us, a multiverse populated by vast sheets of spacetime, a multiverse in which all we consider real are holographic illusions, and even a multiverse made purely of math--and reveals the reality hidden within each.

The bounds of reality: on parallel worlds -- Endless doppelgangers: the quilted multiverse -- Eternity and infinity: the inflationary multiverse -- Unifying nature's laws: on the road to string theory -- Hovering universes in nearby dimensions: the brane and cyclic multiverses -- New thinking about an old constant: the landscape multiverse -- Science and the multiverse: on inference, explanation, and prediction -- The many worlds of quantum measurement: the quantum multiverse -- Black holes and holograms: the holographic multiverse -- Universes, computers, and mathematical reality: the simulated and ultimate multiverses -- The limits of inquiry: multiverses and the future.