The Science Behind the Phenomenon of Time Travelling

Time travelling has been the base of many stories, films and shows for many decades now, each story involves someone or something getting into a machine, and the machine easily flies back and forth through time. Time travelling is a heavily debated topic in the scientific theory, with some scientists still hopeful it is possible. However, theories like Einstein’s theory of special relativity, proposed in 1905, make the idea of time travel seem to be an idea which may be staying in stories.

One theory for achieving time travel would be to try to get faster than the speed of light (3×10^8ms-¹), however when looking at Einstein’s special relativity equations (insert equations), they shows that by achieving over the speed of light the infinite mass and length would have to equal zero, which is not physically possible. Subatomic particles are able to get close to the speed of light, meaning they theoretically are able to time travel. When muons are produced from cosmic rays they do time travel but only by a tiny fraction of time.

The future is still being created, so there is no way of travelling to it, and to travel to the past the amount of space would have to decrease. The only time that space decreases are when stars explode and black holes evaporate, however when these events occur the decrease on time is infinitesimally. These two events are cosmic censorship, meaning they cannot be involved in time travel. (Muller, 2016) Other scientists like Michio Kaku, believe that the other side of blackholes could be other universes, or if something got into close proximity of a black hole, time would slow down enough for to it to pass into the future.

In all theoretical approaches there are many paradoxes that arise when looking at time travel to the past. One of these is the Grandfather Paradox, which links into the no choice paradox. When travelling back in time the person must not disrupt anything which would lead to the change of the present-day time. In the grandfather paradox the person would go back in time and kill their grandfather before he would meet his grandmother, meaning he would have no been created. However, if he was not created then who went back in time to kill the grandfather. It links to the theory that if time travel is real there must be a parallel universe to allow free will to still take place. There has been no proof of parallel universes yet, leading scientists to believe that time travelling must not be able to happen due to forbidden undiscovered laws of physics.

Another issue that is proposed is that never be able to go back in time to before the time machine was created. To be able to travel back in time there needs to be links of different times within spacetime, but before the time machine was created there will be no links.

For time travelling to the past to become a reality a better understanding of maths will be needed, as there are still many gaps in all the current theoretical approaches.