Excerpted fromMany Worlds in One: The Search for Other Universesby Alex Vilenkin. Copyright 2006 by Alex Vilenkin. Published in July 2006 by Hill and Wang, a division of Farrar, Straus and Giroux, LLC. All rights reserved. Prologue The stunning success of the book took everybody by surprise. The author, a quiet, even demure physics professor named Alex Vilenkin, has become an instant celebrity. His talk show engagements have been booked solid six months in advance. He had hired four bodyguards and has moved to an undisclosed location to avoid paparazzi. His sensational bestseller, titled Many Worlds in One, describes a new cosmological theory that says that every possible chain of events, no matter how bizarre or improbable, has actually happened somewhere in the universeand not only once, but an infinite number of times! The consequences of the new theory are mind-boggling. If your favorite football team did not win the championship, don't despair: it did win on an infinite number of other earths. In fact, there is an infinity of earths where your team wins every single year! If your discontent goes beyond football and you are completely fed up with how things are, again Vilenkin's book has something to offer. According to the new theory, most places in the universe are nothing like our Earth and are even ruled by different laws of physics. The most controversial aspect of the book is the claim that each of us has an infinite number of identical clones living on countless earths scattered throughout the universe. Much sleep has been lost over this issue. People feel their unique identities have been stolen. So attendance at psychoanalysts' offices has doubled, and sales of the book have soared. Using his theory, Vilenkin also predicted that on some earths his book would be a phenomenal success. But to be fair, he had to admit there were infinite others where it would be a complete flop... * * * We live in the aftermath of a great explosion. This awesome event, called somewhat frivolously "the big bang," occurred some 14 billion years ago. The whole of space erupted in a hot, rapidly expanding fireball of matter and radiation. As it expanded, the fireball cooled down, its glow steadily subsided, and the universe slowly descended into darkness. A billion years passed uneventfully. But gradually, galaxies were pulled together by gravity, and the universe lit up with myriads of stars. Planets revolving about some of the stars became home to intelligent creatures. Some of the creatures became cosmologists and figured out that the universe originated in the big bang. Compared with historians and detectives, the great advantage cosmologists have is that they can actually see the past. Light from remote galaxies takes billions of years to reach our telescopes on Earth, so we observe the galaxies as they were in their youth, when their light was emitted. Microwave detectors pick up the faint afterglow of the fireball, yielding an image of the universe at a still earlier epoch, prior to the formation of galaxies. We thus see the history of the universe unfolding before us. This wonderful vision, however, has its bounds. Even though we can trace the history of the cosmos to less than a second after the big bang, the bang itself is still shrouded in mystery. What triggered this enigmatic event? Was it the true beginning of the universe? If not, then what came before? There is also a fundamental limit to how far we can see into space. Our horizon is defined by the maximum distance light could have traveled since the big bang. Sources more distant than the horizon cannot be observed, simply because their light has not yet had time to reach Earth. This leaves us wondering whVilenkin, Alex is the author of 'Many Worlds in One The Search for Other Universes', published 2007 under ISBN 9780809067220 and ISBN 0809067226.