Another method might involve travelling in a rocket/spaceship at a very high speed, close to the speed of light. “We can’t establish equality with the speed of light but it is possible, in theory, to travel nearly as fast as the speed of light,” adds Dr Steane. 

So imagine you’re in a spaceship travelling very fast away from the Earth and you stay in orbit for a year. You'd age at the same rate as if you were still on the Earth, by a year, but when you returned, the earth may have aged hundreds of years. “This is way beyond the technology we have at the moment, but in theory, it's possible.” 

So we may one day be able to time travel forwards but what about going back?

“Here we hit the philosophical problem that always comes up when you discuss travelling back in time,” says Dr Steane. "Suppose you could go back in time and you accidentally killed your grandparents. Wouldn’t that mean you couldn’t exist either?"

So how could you go back in time and see people who’ve died - some of them hundreds of years ago?

It's very complex.

However, going back in time goes against the laws of physics- some processes are reversible and some irreversible.

Processes like an avalanche can’t unhappen. Likewise, on a smaller scale, if you drop an egg, you can’t unbreak it.

A spinning top or a pendulum, is reversible because it keeps moving, repeating itself. Nothing really happens. “Within physics, we’re very aware of these issues. The world is irreversible. And so are our lives. We grow, we age, we die,” says Dr Steane.

You can’t reverse the effects of a catastrophic event. And that’s why going back in time is not likely to be possible.

If you’re feeling disappointed that we can’t literally travel back in time then remember there’s nowhere you can’t go in your own mind.

Think about history lessons where you’re asked to imagine yourself in someone else’s shoes from long ago or when you look at old photos of fun times. That’s time travel. And what about when you read a book or listen to a story told by a grandparent?

You can transport yourself to anywhere back in time and the beauty is you can come back. Since isn’t the greatest fear of time travelling getting stuck in a different time zone and never being able to return?