[TheGuardian] Back to the father: the scientist who lost his dad and resolved to travel to 1955 to save himAfter losing his beloved father when he was 10, Ronald Mallett read HG Wells and Einstein. They inspired his eminent career as a theoretical physicist - and his lifelong ambition to build a time machine.
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.
Of course! Dang!
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.
The experiments and explaining? Every tenured prof does.
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.
Skipping a lot of boo hoo about loss and grieving... to the science!
"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.
More at the Guardian.
