British physicist Brian Cox argues that people can travel in time, but only to the future, without the ability to go back.
"Can we create a time machine?" - said a professor from the University of Manchester during his speech at the British Science Festival. “The answer is yes. We can move to the future, we have complete freedom to move to the future."
Such a statement, however, is not a revelation for those familiar with Einstein's special theory of relativity.
To travel hundreds or thousands of years ahead, a person must move in a super-fast spacecraft at a speed close to the speed of light.
Special theory of relativity
This idea is described in the famous "twin paradox":
Promotional video:
Imagine twins, one of whom remains on Earth (twin A) and the other (twin B) travels in a spaceship traveling at near light speed.
Compared to Twin A's time frame, Twin B's time will slow down. If time passes more slowly for Twin B, he will return to Earth when much more time has elapsed, and Twin A is significantly old. The mechanism behind this is called "time dilation," and its effect is stronger the closer you move to the speed of light."
Traveling back in time through a wormhole
Returning from the future or traveling to another point in the past is much less likely, said Professor Cox.
To return to the past, people would have to find the so-called "wormhole". However, the existence of a theoretical bridge or shortest path through space-time proposed by general relativity has not been proven. But even if such a "wormhole" was discovered or created, this does not mean that people could use it to travel in time.
Another scientist, Eric W. Davis, also thinks that a wormhole would be the best way to travel back in time. However, it would take an incredible effort to turn it into a time machine.