Is a wristwatch worth more than half a million dollars? If it belonged to Albert Einstein, the answer isn't relative.

An anonymous bidder has coughed up $596,000 for a gold wristwatch worn by the physicist whose special theory of relativity proposed that time slows down or speeds up depending on how fast things are moving.

Perhaps the buyer hopes its magic will rub off; Einstein took his inspiration from concrete problems of timekeeping, Peter Galison notes in his book Einstein's Clocks, Poincare's Maps.

Einstein received the watch in 1931, as a gift from a rabbi during a luncheon of a Zionist convention at the Ambassador Hotel in Los Angeles, says Michelle Halpern, a spokeswoman for New York auctioneer Antiquorum, which sold the 81-year-old watch yesterday. Einstein emigrated to the United States two years later.

But buyer beware: Don't wear your new watch next to a black hole. It'll stop ticking.

(Image of Einstein in his watch courtesy of Antiquorum)