A WORLD WITHOUT TIME: The Forgotten Legacy of Gdel and Einstein

What if time is only an illusion, if it doesn't actually exist? Yourgrau, a Brandeis professor of philosophy, explains that Einstein's general theory of relativity may allow for this possibility, first realized by the great logician Kurt Gödel. Gödel is best known for his incompleteness theorem, one of the most important theorems in mathematical logic since Euclid. In a typically brief paper written for a Festschrift to honor his friend and Princeton neighbor Einstein, Gödel theorized the existence of what have come to be called Gödel universes: rotating universes in which time travel is possible. But if one can travel through time, how can time as we know it exist in these other universes, since the past is always present? And if time doesn't exist in other universes, then it may not exist in ours either. Yourgrau (The Disappearance of Time ) writes that Gödel's paper was almost universally ignored, and he claims that since the logician's death, philosophers have gone out of their way to try to denigrate his work in fields other than logic. This book will appeal to fans of Douglas Hofstadter's Gödel, Escher, Bach and to Einstein junkies, and makes a fascinating companion to Rebecca Goldstein's Incompleteness (Forecasts, Dec. 20), but all readers who enjoy a good thought experiment or having basic preconceptions about their world challenged will enjoy this. (Jan.)