Richard Feynman once quipped: "Time is what happens when nothing else does." But Julian Barbour disagrees: if nothing happened, if nothing changed, time would stop. For time is nothing but change. It is change that we perceive occurring all around us, not time. In fact, time doesn't exist. In this highly provocative volume, Barbour presents the basic evidence for the nonexistence of time, explaining what a timeless universe is like and showing how the world will nonetheless be experienced as intensely temporal. It is a book that strikes at the heart of modern physics, that casts doubt on Einstein's greatest contribution, the space-time continuum, but that also points to the solution of one of the great paradoxes of modern science: the chasm between classical and quantum physics. Indeed, Barbour argues that the unification of Einstein's general relativity and quantum mechanics may well spell the end of time--time will cease to have a role in the foundations of physics. Barbour writes with remarkable clarity, as he ranges from ancient philosophers such as Heraclitus and Parmenides, to such giants of science as Galileo, Newton, and Einstein, to the work of contemporary physicists such as John Wheeler, Roger Penrose, and Steven Hawking. Along the way, the author treats us to an enticing look at some of the mysteries of the universe and presents intriguing ideas about multiple worlds, time travel, immortality, and, above all, the illusion of motion. Turning our understanding of reality inside-out, The End of Time is a vibrantly written and revolutionary book.