Is our universe just one of many? The most fascinating mysteries in modern physics seem to point us in that direction. As impossible as it seems-that other universes came before ours, float alongside ours, or even mirror ours-the evidence is surprisingly convincing. In his most mind-blowing, sweeping work since Schr dinger's Kittens and the Search for Reality, acclaimed science writer and astrophysicist John Gribbin...