Edward Farhi, the director of MIT’s Center for Theoretical Physics, isn’t familiar with Mallett’s work, but takes a dim view of time travel’s plausibility. Yes, “there’s absolutely not the slightest doubt that time is a flexible thing,” he says. “And there’s also not the slightest doubt that you could go into the future (illustrated by the spaceship example above). But what seems to be unlikely, or impossible, is for you to go back in time. I’ve seen no evidence for it in anything I’ve studied in physics. I’ve seen evidence against it. If you could go back in time, the whole causal structure of physics would change: presumably you could affect things before they occurred, and it’s very hard to imagine a consistent way of doing physics if that could happen.” (As explained by Mallett when discussing any future time machine’s limitations, the two men’s conceptions of travel to the past are not mutually exclusive.)
Nonetheless, recent years have seen Mallett — in a relatively rare collaboration between theoretical and experimental physicists — working with his UConn physics colleague Chandra Roychoudhuri, a research professor who specializes in lasers, on a prototype that might test his theories, which involve laser beams twisting space and time into a traversable loop.
He’d be starting small. “Not only do you want high-intensity laser beams, but over a very small region,” he explains. “The effect becomes greater the smaller the area.”
If that experiment succeeds, then it would be on to the next: trying to confirm that that twisting of space leads to the twisting of time. The idea is to drop tiny neutrons into that tortioned space. If Mallett’s theories held water, the subatomic particles would travel fractions of a second backward in time.
The actual science behind all this is dauntingly complex. And —though he once took out a provisional patent for what he called a LOTART (Laser Optical Time Machine and Receiver Transmitter), an early-warning device that might allow the reception of signals from the future that could warn us of disasters — Mallett concedes that any practical implementation of his ideas is a ways off.
But, he asserts, his theories are sound. “Any criticisms I’ve had have not been about the physics of it. They’ve been questions like, ‘Are you going to [harness] enough energy to do this?’ Technological, engineering questions. Not fundamental physics questions.”
No, Ronald Mallett isn’t building a sleek metallic vessel, into which some intrepid explorer could step for a quick jaunt to the Pleistocene Epoch. “What I have developed is the basic equations that show there is a beginning,” he says. But “the [amounts of] energy and technology that will be needed for [human time travel] are going to be extremely great.”
Also, it’s very expensive. Just the start-up costs for these experiments exceed a quarter of a million dollars. To actually see everything through to completion might cost $11 million.
“What we need is a major benefactor, on the level of Bill Gates,” says Mallett. He sees no reason why someone with loads of filthy lucre shouldn’t want to help. After all, in a world where the much-ballyhooed Large Hadron Collider cost $10 billion, $11 million is pocket change. “This potentially could be a complete revolution in the way the world is,” he says. “That money would be a drop in the bucket for them.”