There are many interesting theories and topics that exist in the world of science, one of these is the concept of time travel.
You must have head about it or seen it in a science fiction movie. Is this concept a fairy tale or is it possible that man can travel back in time?
To understand this concept, we would have to take a closer look at the concept of time dilation and Albert Einstien’s laws of relativity.

It has been proved that the faster you move through space, the slower you move through time ie time moves relative to speed. A little confused. Let’s break it down.

Let us consider a moving truck with two kids playing catch with a golf ball.

Photo Credits: London City Girl

The truck is moving at a constant speed of 50 miles per hour, but as the kids are also moving 50 miles per hour they could think they are standing still as they play the ball towards each other, when they throw the ball 10 miles per hour they observe that the ball moves 10 miles per hour (relative to their position) but an observer outside of the truck observes that the ball, in fact, moves at 60 miles per hour.
The speed of the truck (50miles) + the speed of the ball(10miles) = 60(miles).

But is the outside observer really standing still? No. The earth is constantly moving, the galaxies, the sun are all constantly moving this is otherwise known as classical relativity. Every object moves relative to each other. Even if you stand still, you are still in motion because you have your foot on earth and the earth is constantly in motion and time passes at different rates relative to each other the effect only becomes large when we approach the speed of light.

The speed of light is the same for all observers but time is relative.

Still confused? Hang on.

The Hafele and Keating Experiment.
In October 1971, an experiment was carried out with four cesium super-accurate atomic beam clocks, they were flown on regularly scheduled commercial jet flights around the world twice, once eastward and once westward, to test Einstein’s theory of relativity with macroscopic clocks.
When the clocks returned and were compared to the reference clock, they were no longer in sync and the differences were consistent with the theory of general relativity.

Photo Credits: Droid Sector

This is where things get interesting, let’s say an astronaut travels at the speed of light in space and comes back to earth, many years would have passed on earth whereas the astronaut only spent few years. Never forget time slows down for objects in motion.

Einstein proposed that space and time are not two separate entities but one entity, He called it spacetime.
Time slows down for objects travelling close to the speed of light, and time stops altogether for objects travelling at the speed of light, this then goes to say that time would go backwards for objects travelling faster than the speed of light.
So far, no object has been able to travel at the speed of light, rather than the speed of objects to increase, the mass has been found to increase for objects travelling close to the speed of light.
This is the only reason we’ve not been able to travel back in time. To travel back in time, a speed greater than the speed of light has to be attained.

We would need an infinite amount of energy to be able to attain and move past the speed of light, once we can attain this then we’ll be able to go back in time.

My takeI have had the conversation with folks as to if we can achieve an amount of energy so great that it can move a particle as fast or faster than the speed of light. Many argue that it is not possible and I understand their reasons.
But, let me remind you the breakthrough made by e = mc². It was proposed that it would take a great amount of energy so great to break through the nucleus of an atom to create the nuclear atomic bomb, in fact, the energy required would be so great that it would be more than the energy we’ll ever get back from the nucleus to form a chain reaction. But baam Albert Einstein’s equation changed the whole game and this was achieved with the equation of life and death e = mc².
What if a scientific breakthrough in the 21st century is able to come up with something big?
Hold that thought.