It has long been a mainstay of science fiction adventures like HG Wells's The Time Machine and Hollywood Blockbusters like Back to the Future, but is time travel real? Have people traveled through time in any way outside of their memories? There is no irrefutable proof of time travel, but there is some evidence supporting the possibility it could happen. However, like most things, if time travel is real, it's probably nothing like you see in movies.
Is Time Travel Into the Future Possible?
According to Einstein's theory of special relativity, time travel into the future is possible. For example, if you could travel in your spaceship at the speed of light, then you could take off from earth and accelerate until you reach the speed of light in outer space and then turn around and come back to Earth. In human years, you would have lived 40 years aboard the ship. However, when you get back to Earth, you'd discover that while you were gone 50,000 Earth years had passed.
What makes this happen? Einstein called it time dilation. His theory of special relativity states that the faster you travel, the slower time passes. He called this spacetime, a term used in most science fiction, only it isn't fiction. Scientists tested Einstein's theory of special relativity, time dilation, and spacetime with a very simple experiment. They used identical atomic clocks, placing one onboard a jet and the other stationary on the ground. The clock on the jet ran slower, although it was an infinitesimal difference. However, it was enough to prove Einstein's theory. Because of the results of the experiment, scientists surmised that if you were in a spaceship traveling at least 90% of the speed of light, time for you would be 2.6 times less than the passing of time on Earth.
Of course, current technology doesn't exist that could actually take a human being that far into space with enough power to approach the speed of light. And there's no technology that could protect the person traveling in the spaceship from disintegrating under the force of such velocity. So, barring some top-secret projects of which no one is aware, nobody is known to have accomplished this. Still, Einstein's theory of special relativity means time travel into the future is possible.
What About Time Travel Into the Past?
The math equations used in Einstein's theory of general relativity also indicate that it may be possible to travel into the past. However, to throw a wrench into the traveling back in time, scientists debate the elephant in the room-the grandfather paradox. The typical argument for going back in time is to alter the course of history by preventing some event that had horrific human consequences, such as Hitler or 9/11. The grandfather paradox claims that if you were to travel back in time and kill your grandfather, then you would never be born, creating a paradox. For example, if you can go back in time in one of the closed timeline curves and meet yourself and even interact with your past self, it could result in hurting or even destroying yourself, since both of your past and future selves can't occupy the same space.
Science fiction movies have been made and books written about the grandfather paradox. But a University of Queensland undergraduate student, Germain Tobar, under the supervision of UQ physicist Dr Fabio Costa, says the math indicates there is no chance of a paradox in traveling back in time. The duo claim they've disproved the grandfather paradox, stating their math shows there wouldn't be a paradox because time would automatically course correct. It wouldn't matter what you do when you travel back in time to alter or change events, because time and the events that happened in the past would automatically adjust themselves. The end result would still be the same. The circumstances that caused the event might be different, but you couldn't alter the outcome.
Is There Any Real Time Travel Proof?
There is no public proof that anyone has actually traveled in time. But there is quite a bit of anecdotal evidence that time travel has occurred. Some of the tales are quite compelling. One of the best-known evidence is the video footage that ostensibly offers intriguing evidence supporting possible time travel into the past. Known as the Chaplin Time Traveler, the footage was brought to public attention in 2010 when a film producer saw an outtake from a Charlie Chaplin film from 1928. In the clip, a woman appears to be walking past the camera while talking on a cell phone. Some feel this is evidence of time travel, although the more likely explanation is that she is carrying some type of hearing device that was available in the 1920s.
Attorney Andrew Basiago claims to be a chrononaut (time traveler). Among Basiago's claims, he states that in the 1960s he participated as a child in the U.S.-led time and space travel research called Project Pegasus, and that he time traveled as part of this program on multiple occasions. Among his many claims, Basiago says he traveled back in time to attend the Gettysburg Address and points to a photo of a young man as evidence that he was there. Basiago also claims that as part of another U.S.-led space-time exploration initiative, he teleported to Mars. It's easy to discount such fantastical claims, but when you take a closer look at Basiago's credentials, you discover a highly intelligent person (former Mensa member) who holds five degrees and was a protégé of editor Norman Cousins of the Saturday Review.
The Time Travel Hipster appears in a photo from 1941 in British Columbia, Canada at the opening of a bridge. In the photograph, typical 40s looking people surround a decidedly modern looking young man with sunglasses, an apparently modern camera in his hands, and wearing clothing and a hairdo that looks like hipster fashion. And while many people believe that everything in the images that points to the young man being modern can be explained by items available in 1941, others argue it is evidence of time travel.
No Proof of Time Travel
Some people claim to have time traveled, while others point to photographic/video evidence that can be explained away. While time travel is scientifically possible, so far, no one has offered irrefutable evidence they have traveled back or forward in time.