Time machines - what havoc we could wreak with one of those babies. While the often used staple of sci-fi flicks isn't going to happen anytime soon (or at all), astrophysicist Eric W. Davies says that we need to look to wormholes for our era-hopping antics.
While physicists have proven that particles like muons can be sent forwards in time by manipulating their gravity, the notion of going backwards in time encounters a heap of problems.
Davies, who works at EarthTech International Institute for Advanced Studies in Austin, says that a wormhole could open up a passage in space-time that could send you back in time.
Do Wormholes Actually Exist?
The problem is that there's no proof that wormholes exist, and if they do they're going to be minuscule, so you're not going to be able to jump into one. Still, Davies' paper in the American Institute of Aeronautics and Astronautics' journal outlines how a wormhole could be utilised for time travel.
"Time machines are unavoidable in our physical dimensional space-time," David wrote in his paper. "Traversable wormholes imply time machines, and [the prediction of wormholes] spawned a number of follow-on research efforts on time machines."
He continued, "It would take a Herculean effort to turn a wormhole into a time machine. It's going to be tough enough to pull off a wormhole."
The Quantum Back Reaction
So how exactly could a wormhole work? Well, they would be able to slice through space-time, allowing anything travelling through to reach their destination faster than a beam of light. The problem is that physics could try to do everything in its power to stop this from happening.
Turning a wormhole into a time machine would require huge amounts of energy, so much that it builds up and destroys the wormhole before it can be used as a time machine - which is known as a quantum back reaction.
It's All Relative
But there's still hope for the time travel wormhole hypothesis. General relativity could be the way forward, according to Davis: "I am confident that, since [general relativity] theory has not failed yet, that its predictions for time machines, warp drives and wormholes remain valid and testable, regardless of what quantum theory has to say about those subjects."
So you have two conflicting theories - quantum mechanics and general relativity. You can't just rely on general relativity and ignore the potential effects on a quantum level. The two must be reconciled for scientists to gain a better understanding of whether wormholes could possibly be made into time machines. We need a universal quantum gravity theory.
We've still got a long way to go until these two theories can be intertwined into a seamless single theory, and as elegant as that will eventually be, I doubt we will be zipping off into the past anytime soon.
Source: Live Science