Intro: Have you ever wished to see your future or change your past? So let's find out: "Can we really travel through time without breaking the laws of physics?" Albert Einstein's Theory of Relativity is one of the most famous and widely accepted theories in the world, and one of its most exciting components is time dilation. So let's see what time dilation is…
Imagine you are receding away from a clock at the speed of light, and it is 2 o'clock. In this case, the time will always be 2 o'clock for you since you are moving at the same speed at which the light emitted from the clock (when it was 2 o'clock) is moving. On the other hand, for people who aren't moving at the speed of light, time is moving normally for them. This was
about travelling into the future, but what about travelling into the past??
Time travel into the past complicates matters; First, let's look at how we can truly travel back in time. The process is the same as travelling into the future, so you are receding away from a clock and your speed is way faster than light. Let us suppose you started receding at 2 o'clock. Here you are moving at 2x the speed of light, so just 1 second after you have started receding from it, you will travel 1 sec into the past. This is because you were moving twice as fast as the light emitted by the clock (at 2 o'clock). You'll end up facing the light emitted by the clock when it was 1:59:59 o'clock because you're moving twice as fast as it. But like everything else, this also has a catch. Traveling back in time breaks the laws of physics, as one cannot move faster than the speed of light, and it also creates complex paradoxes such as the famous grandfather paradox.
This allows us to come to the conclusion that 'The Faster You Move Through Space, The Slower You Move Through Time' and also that 'Time Slows Down Near Heavy Objects'. The second conclusion is because of the curved bend created by heavy objects in the fabric of space and time. Due to this bend, the fabric of time also gets stretched and slows down near heavy objects. The same phenomenon was seen in the Interstellar movie: when the protagonist lands on the Blanet (planets that revolve around a black hole), time slows down due to the tremendous gravity of the black hole, where 1 hour on the Blanet is equal to 7 years! Following this line of thought, you could also conclude that your head is slightly older than your feet and the earth's surface is 2.5 years older than its core!