Monday, Dec. 17, 2001
No Time Like The Present
By MICHAEL D. LEMONICK
Albert Einstein stood common sense on its head when he proclaimed time to be just another dimension, like height, width and depth, and went on to declare that it can be stretched and warped like taffy. But that notion is much too mundane for Julian Barbour. According to the 64-year-old British physicist, there's no point in trying to describe time, because it simply doesn't exist. "The passage of time," he says, "is simply an illusion created by our brains."
This unconventional theory comes from an equally unconventional man. After completing his doctorate in physics in 1968, Barbour balked at working in a university, where he would have had to teach, worry about raising grant money and persuade deans to give him tenure. Instead he started earning money by translating Russian articles into English--and did theoretical physics on the side.
The riddle of time had fascinated him all along, and about 15 years ago he tackled it in earnest. Recalls Barbour: "I asked myself, 'How do you get hold of time? It's invisible; you can't really get your hands on it. So what is it really?'" There wasn't any good answer. Although physicists work with time all the time (as it were), they never define precisely what it is. Barbour also knew that at least one physicist, an American named Bryce DeWitt, had managed to meld general relativity and quantum mechanics into a single consistent theory--a major goal of modern physics--by removing time from the equations. But that was generally considered a mathematical trick with no basis in reality.
Barbour thought otherwise. Every "moment" we experience is real, he says, but these moments exist only for that brief instant, during which time literally stands still. The passage of time is as illusory as the sense of movement created by the succession of still frames in a motion picture.
Most scientists are wary of abandoning time, but Barbour's idea is taken quite seriously by such respected physicists as Penn State's Lee Smolin and the University of Alberta's Don Page. There may even be a way to test it experimentally; a consequence of Barbour's theory is that the universe would be filled with more black holes and neutron stars than experts believe. If so, we could know within a decade whether his theory is supported by astronomical observations--and whether the ideas of time we've clung to for most of human history will go the way of the ether and the flat earth.
--By Michael D. Lemonick