The idea of time travel, going back or forward in time is a concept that according to some is possible. While some believe that time travel is possible, others argue.
Dr Alastair Wilson of the University of Birmingham says that we already do so every day.
“Just by walking around we accelerate relative to our environment, which dilates time and causes us to effectively travel slightly faster than usual into the future,” he explains.
Dr Wilson is referring to Albert Einstein’s theory of special relativity, which states that as an object moves more quickly, time will appear to slow down.
However, for an object to truly travel forward in time, the object would need to move at a pace approaching the speed of light – or 186,000 miles per second – an impossibility according to the laws of physics.
Another method of time travel that has been proposed is via a wormhole – a shortcut linking two different times and places.
Einstein theorised that space and time are woven together into a single continuum known as “spacetime”. A wormhole is said to occur when spacetime has been warped, creating a tunnel between two points.
ARE WE ALONE IN THE UNIVERSE?
Professor Stephen Hawking says that these shortcuts spring up everyday. He said that they “constantly form, disappear and reform, and they actually link two separate places and two different times”.
Unfortunately for wannabe time-travellers, these tunnels are just a “billion-trillion-trillionths of a centimetre across”, far too small for a human to enter.
While some scientists have theorised that these wormholes could be enlarged to let a human, or even a spaceship, pass through, Professor Hawking has ruled out them being used for time-travel.
Writing for the Daily Mail, he said: “As soon as the wormhole expands, natural radiation will enter it, and end up in a loop. The feedback will become so strong it destroys the wormhole.
“So although tiny wormholes do exist, and it may be possible to inflate one some day, it won’t last long enough to be of use as a time machine.”
WHAT HAPPENS AFTER YOU DIE?
Will we ever be able to go back in time?
While scientists continue to debate whether we will ever be able to travel forward in time, they are mainly in agreement that it is impossible to reverse the clock.
Dr Wilson explained: “We can’t yet travel backwards in time and if physicists are on the right track then we never will be able to.
“The energies required to even get close to bending time enough to create a spacetime loop would demolish any living thing that tried to traverse the loop.
“My own view is that physical laws are necessary truths, so if time travel is ruled out by physics, then it’s completely, 100% impossible.”
WILL WE EVER FIND A CURE FOR CANCER?
Many experts believe that travelling backward through time could create impossible paradoxes.
Professor Hawking explained a situation where a man travels backwards in time by one minute.
“Through the wormhole, the scientist can see himself as he was one minute ago. But what if he uses the wormhole to shoot his earlier self? He’s now dead. So who fired the shot? It just doesn’t make sense,” he wrote.
The paradox would violate a fundamental rule of physics – that cause some before effect.
Dr Wilson added: “So, no doubt to the relief of Express readers, people won’t ever be able to travel back in time to shoot their grandfathers or kill Hitler.”