Professor's time travel idea fires up the imagination

By David Abel, Globe Staff, 4/5/2002

Ronald Mallett, a physicist at the University of Connecticut, believes he knows how to build a time machine - an actual device that could send something or someone from the future to the past, or vice versa.

He's not joking.

Unlike other physicists who have pondered the science of time travel, the 57-year-old professor has devised a machine he believes could transport anything from an atom to a person from one time to another.

''I'm not a nut. ... I hope to have a working mockup and start experiments this fall,'' says Mallett, who will detail his ideas about time travel tonight at Boston's Museum of Science. ''I would think I was a crackpot, too, if there weren't other colleagues I knew who were working on it. This isn't Ron Mallett's theory of matter; it's Einstein's theory of relativity. I'm not pulling things out of the known laws of physics.''

But Alan Guth, a physics professor at MIT who has studied the theory of time machines, says he isn't sure it's even theoretically possible to travel through time. As far as whether time travel is a possibility, he says: ''Definitely not within our lifetimes.''

Another physicist, Stanley Deser, a professor at Brandeis University who recently co-authored a paper titled ''Time Travel?,'' says the problem is not the physics, it's the feasibility of making time travel work. ''This is about trying to amass all the matter of the universe in a very small region,'' he says. ''Good luck.''

After 27 years at UConn, Mallett has the confidence of his boss, William Stwalley, chairman of the university's physics department. ''His ideas certainly have merit,'' Stwalley says. ''I think some of his ideas are very interesting and they would make nice tests of general relativity.''

Mallett's plan doesn't require some sort of sleigh, the means of transport in H.G. Wells's ''The Time Machine,'' or reaching 88 miles per hour in a flying DeLorean as in the movie ''Back to the Future.'' His time machine merely uses a ring of light.

According to Einstein's theory of gravity, anything that has mass or energy distorts the space and the passage of time around it, like a bowling ball dropped on a trampoline. Circulating laser beams in the right way, by slowing them down and shooting them through anything from fiber-optic cable to special crystals, might create a similar distortion that could theoretically transport someone through different times, Mallett believes.

The professor and his UConn colleagues plan to build a device to test whether it's possible to transport a subatomic particle, probably a neutron, through time. The energy from a rotating laser beam, Mallett hopes, would warp the space inside the ring of the light so that gravity forces the neutron to rotate sideways. With even more energy, it's possible, he believes, a second neutron would appear. The second particle would be the first one visiting itself from the future.

While Mallett acknowledges that sending a person through time may require more energy than physicists today know how to harness, he sees it merely as ''an engineering problem.'' If it's possible to use light to send a neutron through time, a feat that doesn't require as much energy as sending a human, he believes it wouldn't be long before engineers figure out a way to send a person.

''What we're talking about is at the edge of current technology, not beyond current technology,'' he says.

Since his father, a heavy smoker, died at the age of 33 when Mallett was 10 years old, Mallett has longed for a way to travel back in time to warn him about the dangers of cigarettes.

For most of his career, however, Mallett kept secret that his desire for time travel had drawn him to become a physicist. It wasn't until a few years ago, when he began researching a book on the topic, that he arrived at his idea of how to build a time machine.

If his idea pans out, won't there be a host of potential paradoxes, such as time travelers killing their parents and making it impossible for them to exist? No, he says, explaining that those travelers would continue to exist in a ''parallel universe.''

And what about the ethics of changing history?

There would be government laws to control time travel, he believes.

''Any technology has a potential nefarious side to it,'' he says. ''But I don't think there's a way to stop it. We as a species have always reached out. We've been doing that since the caves. I say let's make it so that we better reality. I think we can bravely do that.''

David Abel can be reached at dabel@globe.com.

This story ran on page B1 of the Boston Globe on 4/5/2002.
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