Prof Ronald Mallett thinks he has cracked time travel. The secret, he says, is in twisting the fabric of space-time with a ring of rotating lasers to make a loop of time that would allow you to travel backwards. It will take a lot more explaining and experiments, but after a half century of work, the 77-year-old astrophysicist has got that down pat.
His claim is not as ridiculous as it might seem. Entire academic departments, such as the Centre for Time at the University of Sydney, are dedicated to studying the possibility of time travel. Massachusetts Institute of Technology (MIT) is working on a “time-reversal machine” to detect dark matter. Of course there are still lots of physicists who believe time travel, or at least travelling to the past, is impossible, but it is not quite the sci-fi pipe dream it once was.
However, the story of how Mallett, now emeritus professor at the University of Connecticut, reached this point could have been lifted straight from a comic book. A year after losing his father, Boyd, at the age of 10, Mallett picked up a copy of HG Wells’s The Time Machine and had an epiphany: he was going to build his own time machine, travel back to 1955 and save his father’s life.
Mallett still idolises his dad, and thinks about him every day. He had been exceptionally close to Boyd, whom he describes as a handsome, erudite and funny “renaissance man” who would try to inspire curiosity in Mallett and his two brothers and sister. “When he passed away, it was like this light went out. I was in shock,” Mallett says down the line from his study in Connecticut.
Boyd had gone to bed with his wife, Dorothy, on the night of their 11th wedding anniversary and let out a deep sigh. It was only when she nudged him and his head flopped off his pillow “like a sack of flour” that Dorothy realised something was wrong. Mallett woke later that night to his mother crying uncontrollably and the news that his father had died of a heart attack. “I couldn’t comprehend how this was possible. To this day, it’s hard for me to believe he’s gone. Even after 60 some years,” he says.
Boyd had fought in the second world war and then, on his return home, used the GI bill, which helped qualifying military veterans with their tuition fees, to retrain in electronics. He would bring home gyroscopes and crystal radio sets, taking them apart and explaining how they worked to his children. After the family moved to a new apartment complex in the Bronx in the late 40s, Boyd took on work as a TV repairman.
“I adored him,” says Mallett. “One of the great pleasures for me was meeting him when he got off the subway and carrying his toolbox home with him. He just literally lit up the room when he would come in.”
Even though Boyd earned a modest living, he spoiled his children and their mother. “He worked very, very hard, he loved having a family, and he loved playing with us,” Mallett says. “One of the last things that I remember was – [on] one of the last Christmases – we wanted a bike, and he took on extra work. And all three boys got a bicycle; it was incredible for him to do that.”
After Boyd died, the bubble of safety he had created for his family vanished. Dorothy and the children moved to Altoona, Pennsylvania, to be closer to her parents. One day, as Mallett and his brothers were walking around their new neighbourhood to meet friends, they saw four white boys playing nearby and approached them to say hello. When they got closer, one of the kids spat the N-word at them. No one had ever called Mallett that before. Something in him snapped and he punched the boy until he apologised. “I was in the dark already. And that just added to that, I think. I was becoming unravelled because I was in a very deep depression after he died,” says Mallett.
Mallett never had cause to contemplate his race in the Bronx. “The neighbourhood that we lived in was predominantly a white Jewish neighbourhood. And I’d never experienced any feeling of prejudice. I was actually the only African American in the predominantly white Jewish Boy Scout troop, and I felt I was not treated any differently from any of the others,” he says.
Mallett became a truant and withdrew into the comforting fantasy world of books and magazines. One of these books was The Time Machine. “It somehow just spoke to me,” he says. “The very first paragraph changed my life. I still remember the quote: ‘Scientific people know very well that time is just a kind of space and we can move forward and backwards in time, just as we can in space.’” Inspired by the picture of the time machine on his illustrated copy, Mallett cobbled together a replica from his bicycle and his dad’s spare TV and radio parts. But, of course, it didn’t work.
In films, travelling through time is as easy as sharing a phone box with George Carlin, à la Bill and Ted; hitting 88mph in a DeLorean kitted out with a flux capacitor as in Back to the Future; or spilling a supercharged energy drink over a hot tub’s control panel, as in the 2010 film Hot Tub Time Machine. In reality, it’s slightly trickier. Well, travelling into the future is easy – we’re all doing it now in fact – but going back in time presents a far bigger problem.
Undeterred, Mallett kept reading. He came across an Einstein paperback. Even at age 11 he got the gist that, according to Einstein, time is not absolute. Mallett rationalised that the key to seeing his dad again was understanding everything in that book, so back to school he went, rising quickly to the top of his classes and graduating with straight As. Without the funds to go straight on to college, he joined the air force, intending to use the GI bill as his father had. “It was a very, very solitary life,” he says. He chose the graveyard shift so that he could study and “was just in my world, in my books”.
After the air force, Mallett enrolled at Pennsylvania State University and became one of the first African Americans to receive a PhD in physics. However, despite his academic success, he didn’t have the confidence to publicly discuss time travel. It was the 1980s and talking about it was still unheard of in “serious” academic circles; doing so could be career suicide. Plus, growing up in white America had taught him that no matter how high he climbed, he was still in danger of being disrespected.
It wasn’t until the mid-90s, when people were starting to talk about the possibility of time travel, that Mallett felt ready to be more open about his endeavour. Heart problems meant he had to have angioplasty surgery and he spent his months of recovery poring over his research. Mallett found his eureka moment in a black hole.
“It turns out that rotating black holes can create a gravitational field that could lead to loops of time being created that can allow you to go to the past,” says Mallett. Unlike a normal black hole, a spinning black hole has two event horizons (the surface enclosing the space from which electromagnetic radiation cannot escape), an inner one and an outer one. Between these two event horizons, something called frame dragging – the dragging of space-time – occurs.
“Let me give you an analogy,” Mallett says, with patience. “Let’s say you have a cup of coffee in front of you right now. Start stirring the coffee with the spoon. It started swirling around, right? That’s what a rotating black hole does.” But, he continues, “in Einstein’s theory, space and time relate to each other. That’s why it’s called space-time. So as the black hole is rotating, it’s actually going to cause a twisting of time.”
Although black holes are in short supply in this corner of the Milky Way, Mallett thinks he may have found an artificial alternative in a device called a ring laser, which can create an intense and continuous rotating beam of light – “light can create gravity … and if gravity can affect time, then light itself can affect time,” he explains.
Some of Mallett’s critics have objected that his time machine would have to be the size of the known universe, thus completely impractical. I put this to him. “You’re absolutely right; you’re talking about galactic types of energy in order to do that,” he acknowledges.
So, how big would your time machine be? “I don’t know that yet. The thing is that what is necessary first is being able to show that we can twist space – not time – twist space with light.” Only then, he says, will he know what is necessary to do the rest. Mallett likens it to asking the Wright brothers, straight after their maiden flight, for their predictions for how humans will reach the moon. All Mallett can tell us at the moment is that his time machine, however big, will look like a cylinder of rotating light beams.
Such an endeavour would, of course, not come cheap, but it’s highly unlikely that any government would pour its resources into time travel, and the only billionaire wacky enough to potentially fund such a project is busy with Mars and Twitter. Plus, here’s the rub. Even if clever engineers and barmy billionaires put Mallett’s theories into practice, it would only allow travel back in time to the point when the time loop was created, which could never be 1955. For all Mallett’s work and theories, there is no possibility of him travelling back to see his dad again.
How did he feel when he realised? “It was sad for me but it wasn’t tragic, because I remember that there was this little boy who dreamed of the possibility of having a time machine. I have figured out how it can be done.” Mallett also takes comfort in the enormous potential his machine could have for the wellbeing of life on our planet. “Let’s suppose that we had already had this device going on some years ago, and now we have medicines that can cure Covid. Imagine if we could predict precisely when earthquakes are going to occur, or tsunamis. So, for me, I’ve opened the door to the possibility. And I think that my father would have been really proud about that.”
