Mention “time traveler” in a discussion and the names H.G. Wells, Doc Brown, Albert Einstein and Stephen Hawking usually come up. Soon, that list may include astrophysicist Ron Mallett. He claims he’s built a prototype time machine that uses lasers to twist space and time, allowing trips back into the past. Does it require a flux capacitor and an extinct sports car?
"What Einstein meant by that is the stronger gravity is, the more time will slow down. If you can bend space, there's a possibility of you twisting space."
Ron Mallett is an astrophysicist and tenured physics professor at the University of Connecticut, so he knows he’s going up against Einstein’s special theory of relativity and general theory of relativity when proposing that it’s possible to travel backwards in time. As he tells CNN:
“So the upshot is that, according to the special theory of relativity, if you're traveling fast enough, you respectively are traveling through time. And effectively, that would be a representation of time travel."
Most people understand, or have at least heard of, the idea (and “Planet of the Apes” plot) that traveling at or near the speed of light causes one to age more slowly and the return to normal speed puts that person in the future. However, that doesn’t work in reverse, despite the plot of “Back to the Future.” Various theories on how to warp spacetime – wormholes, for instance – but a variation of the Fermi paradox begs for a concrete non-theoretical answer: if travel back into the past is possible, why don’t we see any visitors from the future.
"It turned out my understanding about lasers eventually helped me in my breakthrough with understanding how I might be able to find a whole new way for the basis of a time machine. By studying the type of gravitational field that was produced by a ring laser, this could lead to a new way of looking at the possibility of a time machine based on a circulating beam of light. Eventually a circulating beam of laser lights could act as a sort of a time machine and cause a twisting of time that would allow you to go back into the past."
Mallett is a laser expert, so it’s natural that’s the tool he used to build a prototype time machine. Building on the concept from the general theory of relativity which relates the gravity of massive objects to bending spacetime, Mallett built a ring laser -- two beams of light of the same polarization traveling in opposite directions in a closed loop – similar to the type used in gyroscopes. In a theory presented in a 2017 scientific paper, a ring laser can measure “the general relativistic effects of the rotation of the Earth, as manifested on the surface of the planet.” In Mallett’s way of thinking, a gravitational field of that size produced by a ring laser could theoretically be used to twist time.
So, does his prototype allow him to do a Doc Brown trip back to visit his deceased father, a longtime driving in Mallett’s work?
“You can send information back, but you can only send it back to the point at which you turn the machine on.”
The catch. There’s always a catch. Mallett’s twisted time loop is limited to the first time the time machine is turned on, so he can only travel back to 2019. That’s still a feat, isn’t it? CNN asked Paul Sutter, an astrophysicist who hosts a podcast called "Ask a Spaceman!"
"But every time we try to concoct a theoretical time travel device, some other bit of physics busts in and breaks up the party."
No one wants to break up the party, let alone spoil the plot of a good sci-fi flick. Neither does Mallett, who says his favorite time-travel movies are “Timecop” and “Interstellar.” He says a major production company has bought the rights to his story and admits that seeing his father on a movie screen will, in a sense, be a time machine for him.
Maybe, but a video of his ring loop laser time machine sending him ‘back to the future’ would be a blockbuster.