There are a lot of theories on time travel. Some people think it is possible, while others write it off as a concept best left to sci-fi movies. However, some of the greatest minds in history stated that they believe time travel is possible. This idea just got a huge push back into the “true” category of things after scientists at the University of Queensland sent a particle of light travelling back in time to meet its former self.
The scientists published their findings in Nature Communication. The research involved sending one photon, which is a particle of light, back in time to meet its former self. After the experiment was a success, it left a lot of people wondering if time travel for humans is really possible.
Physics professor Tim Ralph, at the University of Queensland, said that time travel was simulated by using a second photon that played the part of the past incarnation of a time travelling photon. The experiment was done to test out Einstein’s theory of relativity.
PhD student Martin Ringbauer said that the question of time travel relies on two physical theories: Einstein’s general relativity and quantum mechanics. According to Einstein’s relativity theory, it may actually be possible to travel backwards in time. This would be done following what he called a “space-time path.” A space-time path would double back and return to its starting point. So following the path would spend an object back to an earlier point in time. Physicists refer to this path as a “closed time-like curve.”
During the experiment, researchers ran two different tests. The first involved looking at what would happen if a photon that was travelling through a wormhole ended up interacting with its older self. The next case involved them investigating what might happen if a photon travelled through normal space and time and interacted with another photon that was trapped inside the closed time-like curve forever.
Science Alert explains that, for a long time, physicists and philosophers believed in what they called a grandparent paradox. The theory is that if a person travelled back in time and kept his grandparents from ever meeting, it would prevent the time traveller form ever being born. If the time traveller kept his grandparents from meeting, he was never born. However, if he was never born, he never went back in time in the first place. As a result, he would have not kept his grandparents from meeting.
Of course, do not pack your bags for time travel just yet. Although this new research suggests that these kinds of paradoxes might not render time travel impossible, time travel is only possible on a quantum level for now. So, for now, there will be no way a person could go back in time and give himself the winning lottery number.