When it comes to physics one of the first facts that we learn is that there is nothing faster than the speed of light which is roughly 3,000,000 m/s. To put that into perspective, a train travelling at the speed of light would travel around the earth 7.5 times in just 1 second.

But would it be actually like for the passengers sitting in the train?

Scientists have come up with many theories by following the Time Dilation Theory of Einstein. According to which we can come up with the idea that as we approach towards the speed of light the time tends to approach to zero. In our example, it would mean that the passengers inside the train would experience less time compared to one on outside as we come closer to the speed of light.

For a better explanation, let us take our example to outer space.

The closest solar system (star system)  outside our solar system is Alpha Centauri which is about 4.2 light years away. If we travel in a spacecraft that can achieve the speed of light then it would take us nearly 4 years to reach our destination but here comes an interesting part. Though the time taken to reach our destination will be 4 years the time experienced by you would be entirely different. Taking in time dilation factor which is roughly 4.47%, the actual time experienced by you would be only 65 days.

Now assuming you instantly decide to make a return trip to earth which would cost you another 65 days but when you reach earth everyone would be older by 8 years whereas you, on the other hand, would be just older by 130 days.

Weird right?

I know it is quite difficult to wrap around our heads on these facts but that’s how our universe works. And that's the beauty of it.