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Time travel is 'possible' -- mathematically anyway

A researcher crunches the numbers on time travel using his own TARDIS. Also, a weird new material could be the real-world version of a flux capacitor.

The math backs up Doctor Who's favorite means of travel.
TARDIS image by Sceptre, CC BY-SA 2.5; Boomerang Nebula image by ESA/NASA, public domain

Pull out your list of regrets, mistakes and runs of just plain bad luck, because it turns out you can go back. A University of British Columbia professor has run the numbers on the feasibility of time travel, and he says they check out.

"People think of time travel as something fictional," math and physics instructor Ben Tippett said in a news release Thursday. "And we tend to think it's not possible because we don't actually do it. But, mathematically, it is possible."

It's a finding that's sure to inject new energy and vigor into late-night, half-sober arguments about the morality of traveling back in time to assassinate Adolf Hitler before his rise to power.

Tippett created a formula based on Albert Einstein's theory of general relativity, which states that huge cosmic objects like stars and black holes distort space and time. The recent detection of gravitational waves created by distant colliding black holes confirmed Einstein's theory.

Large stars can actually cause the fabric of the space-time continuum to curve, which Tippett says contributes to the curved orbits of planets as they move through space.

"The time direction of the space-time surface also shows curvature. There is evidence showing the closer to a black hole we get, time moves slower," he explains. "My model of a time machine uses the curved space-time -- to bend time into a circle for the passengers, not in a straight line. That circle takes us back in time."

Oh, cool. So all we have to do is build this time-bending machine and we're off to 2012 to bet everything we have on the then-laughably long odds of a European Union without the UK, a US president named Trump and the world champion Chicago Cubs.

Actually, Tippett says not so fast, McFly.

"While is it mathematically feasible, it is not yet possible to build a space-time machine because we need materials -- which we call exotic matter -- to bend space-time in these impossible ways, but they have yet to be discovered."

Tippett's research was published in a recent issue of the journal Classical and Quantum Gravity.

Of course, not all physicists are ready to climb aboard Tippett's hypothetical time machine, which he cleverly named the "Traversable Acausal Retrograde Domain in Space-time," or TARDIS, in a nod to the iconic time-traveling booth from "Doctor Who." No less than the world's most famed cosmologist, Stephen Hawking, has said that if time travel is possible, we certainly wouldn't be able to go backward in time.

But Tippett's calculations show that his TARDIS, which is really just a conceptual bubble of space-time, can move backward and forward by moving at speeds that would exceed the speed of light at times.

I seem to remember another famous brainiac concluding that nothing could travel faster than the speed of light. In fact, it was the same Mr. Einstein that inspired all this far-out speculative math to begin with. However, if it were possible to break that barrier, Einstein said it would be essentially equivalent to time travel.

So now that we may have the math down, are we actually any closer to building a time machine and visiting a certain field near Roswell, New Mexico, in 1947 just to see who shows up? All we need to do is break the speed of light barrier and get ahold of some physics-defying exotic matter that may or may not be real.

As it turns out, just this month researchers said they have created a fluid that possesses negative mass, one of the characteristics of the type of exotic matter we'd need to bend time.

So you might say we're progressing quite nicely toward making time travel a reality, but it sure would be nice if someone from a future where they've already got it figured out came back to help us out. Time to keep a close eye out for any real-world TARDISes and Time Lords.

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