Time travel has always been a fascinating topic to discuss with a group of friends. But every time, we simply end up with, “I wish that was possible, so we could travel back in time.” Let’s discuss it in more detail. According to Einstein’s theory of relativity, any object having mass cannot travel faster than the speed of light, and we know that almost every object in this universe has some amount of mass. Even if we want to accelerate an object of mass faster than the speed of light, we have to provide energy not equivalent to but twice the speed of light to make time travel possible for it. But that’s practically not possible because our universe contains a finite amount of energy, which is always less than the speed of light. This means that we cannot move faster than the speed of light.

However, an interesting phenomenon that is worth mentioning here is that there are some hypothetical particles known as “tachyons” that have “imaginary mass.” Human beings haven’t discovered the existence of tachyons through experiments or research yet, but if we just “suppose” that they exist in one way or the other, then we can simply accelerate them more than the speed of light. It would also be possible for them to travel back in time easily because of having no mass.

In other words, they cannot be slowed down to travel less than the speed of light, i.e., 3×10 (8) m/s, and that is the reason why tachyons are always associated with time travel in fiction movies and books. As we have stated before, it is “imaginary,” so it would always be possible in “fiction” because human beings are unable to explore the possibility of their existence as of now.

Let’s just think about what would happen if we could actually travel faster than the speed of light. There are endless possibilities to consider, but the fact here is that even if we could travel, the nearest star to Earth that we could reach is 4.35 light-years away, which means that it would take us more than four years to arrive there even if we were traveling twice the speed of light. Researchers believe that there are “wormholes,” which is the shortest distance between any two points in space.

So, we can say that, through wormholes, we could really go to another star in just a few hours. That’s breathtaking, isn’t it? Yes, but only in fiction.