No one has yet managed to travel through time – at least to our knowledge – but the question of whether or not such a feat would be theoretically possible continues to fascinate scientists.
As movies such as The Terminator, Donnie Darko, Back to the Future and many others show, moving around in time creates a lot of problems for the fundamental rules of the Universe: if you go back in time and stop your parents from meeting, for instance, how can you possibly exist in order to go back in time in the first place?
It’s a monumental head-scratcher known as the ‘grandfather paradox’, but a few years ago physics student Germain Tobar, from the University of Queensland in Australia, worked out how to “square the numbers” to make time travel viable without the paradoxes.
The secret to reverse time travel without paradoxes is to go to a parallel universe. Einstein and certain others theories allow for the existence of multiverses, each with its own laws of physics, own timeline, etc. By travelling to a parallel universe, you would mess with the history of that universe, rather than this one. That way for example, you could prevent your grandfather from meeting your grandmother and still not fade from existence entirely. This is further supported by the fact that the most feasible time machine theoretically possible is the wormhole, and wormholes are thought to bridge two different eras and \ or universes.