A WORLD WITHOUT TIME

It is a widely known but little appreciated fact that Albert Einstein, the twentieth century's greatest physicist, and Kurt Gödel, its greatest logican were best friends for the last decade and a half of Einstein's life. They walked home together from Princeton's Institute for Advanced Study every day; they shared ideas about physics, philosophy, politics, and the lost world of German-Austrian science in which they had grown up. What is not widely known is the discovery that grew out of this friendship. In 1949 Gödel published a paper proving that there exist possible worlds described by the theory of relativity in which time, as we ordinarily understand it, does not exist. He went further: if it is absent from those theoretical universes, he showed, time does not exist in our world either. Einstein's great work has not explained time, as most physicists and philosophers think, but explained it completely away.
Einstein recognized Gödel's paper as "an important contribution to the general theory of relativity." Physicists since then have tried without success to find an error in Gödel's physics or a missing element in relativity itself that would rule out world models like Gödel's. Stephen Hawking went so far as to propose an ad hoc modification of the laws of nature--a "chronology protection conjecture"--specifically to negate Gödel's contribution to relativity. Philosophers have been largely silent--and their silence, says Palle Yourgrau, is one of the intellectual scandals of the past century. (book jacket excerpt)

A World Without Time: The Forgotten Legacy of Godel and Einstein
hat tip Tom Harris