Is Time Travel Really Possible?

Marty McFly and Doc Brown did it with a plutonium-powered DeLorean back in the eighties. But is it really possible? Is there really a chance that one day people will be able to travel in time.

Imagine the possibilities. What if you had a machine which could take you back to say Victorian London or maybe Ancient Greece. Alternatively, perhaps you would use it to head into the future and get a glimpse of how things are going to change for mankind. Wherever or whenever you chose to go, it would certainly make for a thrilling ride.

Time travel has been a theme of science fiction for many years. In 1895, HG Wells wrote The Time Machine, a novella in which an English inventor travels into the distant future. In The Time Machine, Wells wrote: "there is no difference between time and any of the three dimensions of Space, except that our consciousness moves along it."

If we are going to talk about the science of time travel, the we have to talk about Einstein. Albert Einstein put forward his general theory of relativity in 1910, ten years after the publication of The Time Machine.

It was Einstein who first came up with a mathematical equation which related both time and space in the form of 'space-time.' The equations and theory suggest that time travel is not impossible.

In his 2002 book How to Build a Time Machine British physicist Paul Davies details some ideas on how time travel might be possible.

Davies reckons that to travel into the future you need a spaceship that can reach speeds just under the speed of light. For travelling back in time, he suggests that wormholes could be adapted to create time machines.

A wormhole is like a blackhole, but with an exit, as well as an entrance. Theoretically, travelling through a wormhole would enable somebody to travel through space-time. This means they could travel from one part of the Universe to another in an instant. This is all theory though and no one quite knows how to change a black hole into a wormhole.

Making wormholes is the tricky part, but there is a chance that they might be created by accident. Some think that the Large Hadron Collider at CERN in Switzerland may hold the key to time travel.

The LHC is the world's largest and highest-energy particle accelerator. It was built to explore the forces that exist at the level of sub-atomic particles. The main purpose of the LHC was to find the Higgs boson, a particle that physicists use to explain why particles like protons, neutrons and electrons have mass.

Some scientists proposed that the LHC could create the conditions for time travel. They suggested that additional particles would be created, which would have the ability to jump into an extra fifth dimension. They could then move forward or backward in time and reappear in the future or past.

However, if this were at all possible, it would still only mean that nothing bigger than a single particle could be sent through time.

Because the LHC could not send anything back in time smaller than an atom it rules out one of the big paradoxes of time travel.

What would happen if somebody travelled back in time and did something to prevent their own existence? Since, the LHC isn't going to be sending anything bigger than an atom, that's not something we need to worry about. We shouldn't be expecting any visitors from the future any time soon. In fact, Most scientists have ruled out time travel backwards.

Theoretically, time travel into the future is possible. Just because it is possible though doesn't mean that it will happen. It may be possible in theory, but the practical problems make it highly unlikely.

The chances of a time machine, like the one in HG Wells' classic 1895 story, becoming anything more than science fiction are very slim indeed.