Time Travel

Time travel is something which fascinates all of us. Although many people believe that time travel is strictly science fiction, it is not. Actually, as odd as this may sound, we are all time travelers. We are traveling from the present to the future. From the moment, you started reading this, we have already travelled 15 seconds into the future.

We measure our movement in time in arbitrary units. The measurement may be in seconds, minutes, hours, etc. During 2018, I’ve moved forward one year and so have you. Another way to say this is that we travel in time at the rate of 1 hour per hour. But the question is, can we travel in time faster or slower than “1 hour per hour”? Or can we actually travel backward in time, going back, say 2 hours per hour, or 10 or 100 years per hour?

It is mind-boggling to think about time travel. What if you went back in time and killed your grandfather. You would prevent yourself from ever having been born! But then if you hadn’t been born, you could not have gone back in time.

One of the very first time travel stories recorded in history appears in the Hindu epic, Mahabharata. The story follows a king Kakudmi, his daughter Revati and their search for a perfect match. Unable to find a suitable match for her daughter, Kakudmi took Revati to Brahmaloka, to seek Brahma’s advice about finding a suitable husband for her. Brahma was listening to a musical performance when they arrived, and so they waited for 19 minutes until the performance was finished. When they met Brahma, he told them that during the time they had waited to meet him, 27 chatur-yugas, or 116 million years had passed on earth. Brahma also explained that time is different on different planes.The King and his daughter were in grief as they had lost everything by then, but Brahma comforted them, and recommended a worthy husband currently on earth: Balarama, the brother of Krishna.

Travelling in time might sound like a flight of fancy, but some physicists think it might really be possible. Einstein’s special theory of relativity, published in 1905, was the first to give scientific meaning to forward time travel. This theory predicted a strange new phenomenon, time dilation, which is a phenomenon where time moves slower for any mass accelerated near the speed of light. Time dilation is an experimentally verified fact.

According to this theory, space and time are really aspects of the same thing—space-time. Time is relative depending on how fast you are moving. The faster you move through space, the slower you move through time. Light travels at a speed of 300,000 kilometers per second which is the maximum speed for anything that travels through space-time. So, if you leave the earth for a journey in 2019 in a spacecraft travelling at about 99.5 % of the speed of light and come back after 5 years, it will be 2069 on earth. This is a way of going to the future at a rate faster than 1 hour per hour.

Time travel may be theoretically possible, but it is beyond our current technological capabilities. Till now, we have not been able to build a time machine to send larger objects, like humans, into the future.  It is impossible using today’s science to build a spaceship capable of traveling close to the speed of light. Today’s science is only able to accelerate subatomic particles close to the speed of light.

In all time travel theories allowed by real science, there is no way a traveler can go back in time to before the time machine was built.

With the advancement of technology, the impossibilities of yesteryears have become reality today. With the further advancements in technology, time travel will also become a reality someday. It will be a futuristic time but it will surely be a fantastic travel.