David Stonehouse Features

Let's do the time warp again

Scientists conjecture that time travel could be more fact than fiction. Back to the future, or what?

By David Stonehouse

SHEDIAC RIVER, N.B. -- Paul Davies, a world-renowned scientist with the nickname Dr. Time, is on the phone from Australia explaining the subtleties of time travel to someone who barely understands the subtleties of science.

On one point, he is helpfully blunt: Throw out any ideas about climbing into a mechanical transporter, throwing the lever and enjoying a thrill ride through the vast reaches of the ages.

"You can't really do what H. G. Wells did," says Davies, who really has written the book on the subject -- a surprisingly small volume entitled How to Build a Time Machine (Penguin). "Clearly, it is not on."

If Davies is the doctor, H. G. Wells was the pioneer. The legendary writer slipped the idea of time travel into the collective imagination more than a century ago with The Time Machine -- the story of a scientist who amazes his dinner companions with an invention that rockets him 800,000 years into the future.

The story itself has endured through the ages: A modern adaptation of his 1895 tale hit the theatres yesterday, directed by great-grandson Simon Wells and starring Guy Pearce as the time traveller who invents a contraption that will transport him to the past so he can try to prevent his girlfriend's murder. The machine also takes him on a ride into the distant future where he comes face-to-face with creatures inhabiting the Earth.

The sci-fi action adventure is sure to reignite interest in the magical notion of travelling through the ages. In a twist of clever timing, Davies's book was released in the United States this week. It has been available in Canada and Britain since November.

Davies, a British-born physicist living in Sydney, Australia, makes it his mission to explain complex science to the masses. He is the author of more than two dozen books, including The Cosmic Blueprint, The Mind of God and The Fifth Miracle.

In How to Build a Time Machine, he maps out a four-step process to devising a time transporter that looks nothing like what you'll see in the movie. In fact, it's very conceptual. Davies himself admits that pulling something like his idea together is beyond the capabilities of modern society. But he'll argue that is not the point -- he just wants to explain to people how such a once-fanciful notion might someday become real.

"The wormhole time machine makes complete sense. You'd jump through the wormhole and you come out not only somewhere else, but somewhen else," he says. "You go through and you come out, say, 50 years ago."

A wormhole is a galactic shortcut connecting two different universes. No one knows for certain if they exist, though researchers surmise these cosmic tunnels connect not just disparate points in space but time as well.

Leading physicists around the globe are keenly investigating wormholes and how they might serve as time machines. The sudden interest in wormholes arose in the 1980s after an innocent inquiry by the late Carl Sagan. The noted astronomer and Pulitzer Prize-winning author was working on Contact, a novel about a young astronomer who stumbles on radio signals from space that turn out to be alien blueprints for a spaceship.

But Sagan had a problem: He wanted to put his main character onto the ship for a voyage to a distant star -- a trip that would span far beyond a human lifetime. So, he slung her through a black hole as a shortcut. But something nagged at him. It just didn't seem right.

He picked up the phone and called Kip Thorne, a friend who was an expert on black holes at the California Institute of Technology. Thorne was somewhat taken aback.

"I was a little upset because he had the heroine in his novel travelling through a black hole and I knew that you can't go into a black hole and come out somewhere else," Thorne recalled in an interview for a 1999 PBS documentary. "The fundamental laws of physics forbid it."

In fact, get sucked into a black hole and there is no coming out -- ever. The dark vortexes with tremendous gravitational pull destroy everything they pull inside. Sagan would be sentencing the young astronomer to death. But Thorne began working on an alternative, scribbling out pages of calculations before settling on the wormhole.

When Contact was transformed into a movie starring Jodie Foster five years ago, audiences watched a filmmaker's vision of a wormhole at work -- catapulting Foster on a furious ride through the galaxy to the star Vega, and doing it in record time.

Not long after Thorne made his suggestion to Sagan, he realized wormholes could be time warps too. It seemed such a simple finding that he was amazed it had not been discovered before. He published a paper on his research and set off a flurry of interest in wormholes as potential time machines.

"At last," Davies writes, "physicists had found a plausible way to travel back and forth in time. But how might a wormhole time machine be made?"

Davies sets out his ideas of how wormholes of outer space might be manufactured in the inner space of Earth, casting his eye to the microscopic dimensions within the atomic world where scientists believe there are all sorts of minuscule wormholes.

He believes those tiny wormholes could be isolated by being targetted with intense energy, zapped with a series of lasers to inflate them and keep them open, charged with electricity and whirled around at high speeds for several years. All that, he believes, would produce a wormhole large enough to allow a person or an object to ride through.

There's one big problem: We can't pull it off. Just to keep the wormhole from collapsing would require vast amounts of antigravity, also called negative energy. According to Washington University theoretical physicist Matt Visser, we would require negative energy equivalent to the mass of Jupiter just to keep one wormhole open. And that's just one step in the Davies wormhole factory.

"Clearly the way I suggest doing it, with a four-stage process, is something that would tax the resources of a super civilization," Davies concedes in the interview. "This isn't something that is going to happen in a 100 years -- or even in 1,000 years -- of technological development."

Unless, he notes, there is a revolution in physics that will reveal how these things might be done in a more manageable way.

There are some, though, who doubt the plan would work -- even if we had the tools.

"I tend to be pretty skeptical," says William Unruh, an expert in black holes at the University of British Columbia. "I think it is fascinating as a theoretical possibility, but that same theory says that it is pretty hard to accomplish."

Unruh, who worked with Davies for a year in the 1970s, worries that generating fields of negative energy to keep the wormholes from collapsing would create instability in the universe.

Technical details aside, there are some fundamental and troubling questions lingering over time travel itself -- particularly trips back in time.

"What happens if you went back and shot granny dead as a little girl?" Davies explains. "Well, then you would never be born. But if you were never born, you could not have gone back and done that anyway."

Going back and tinkering with history could have profound consequences, indeed.

This is why Davies says H. G. Wells's vision of roaming the ages in a time machine just doesn't work.

"This is a bit of a fantasy really. I could envision that a super civilization out there on the other side of the galaxy that has been around for a 100 million years might have got on top of this a while ago," he says.

"But the idea that we would all have time machines like we have cars I think is a bit fantastic. Because once you allow the idea of looping back into the past, all bets are off. The whole nature of our society, our relation to the world around us, would never be the same again," he says.

"I mean, for a start, supposing I had a time machine. I just have to go forward a week and check out the lotto winning number then come back and place a bet, then instantly I am rich. And I can do that any umber of times I chose. Very soon, I am going to be in charge of the whole planet," he says, and lets out a little laugh at the absurdity of it all.

"The notion of travelling in time is the most disruptive technology that we could ever imagine."

Such a dire warning sounds odd coming from a scientist who just wrote a book about how we might someday devise that technology. But he says it is important for science to understand the mechanics of time travel, if only to unravel more clues to the nature of the universe.

"This is a world away from saying we should actually build a device and allow people to use it."