International Business Times

Going into the future is definitely possible, but going back to the past, that's difficult," Professor Jerome Gauntlett, chair in theoretical physics at Imperial College, tells IBTimes UK.

"There are two ways to go into the future – One way is to hop into a rocket. If you accelerated near the speed of light and then turned around and came back to Earth, as long as you're going close enough to speed of light, you will come back and everyone will have aged as many years as you like, e.g. if you wanted to come back in 30 years.

"It's a theoretical possibility, but it's difficult as you have to get in a rocket that can go close to the speed of light."

The second way, Gauntlett explains, is to take a spaceship very close to a black hole, which is known as an "event horizon". According to physics, if you cross the event horizon, you can never come back, but if you were to take the spaceship close to the black hole and then come back to Earth, you would find that the people on Earth would have aged.