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Car travel. Bus travel. Train travel. Time travel. Pick the odd one out.

If you chose time travel, you are right in the sense that time is not a vehicle that we can use to travel. But is it possible to travel through time? Can we visit our past and take a sneak peek into our future? The answer is yes for all of the above, how much ever absurd it sounds now, it is likely in the future. It is not impossible. One day we should be able to Time travel.

Time travel has always been one of the biggest fantasies for all. Imagine travelling back in the past to see your mother rocking you as an infant or travel in the future to see what you will become. Science seems to have provided enough breakthroughs that point towards the possibilities of travelling either back in time or into the future. The most important breakthrough came when Albert Einstein discovered and wrote about the theory of relativity.

Theory of relativity led to unraveling of many concepts in the field of physics and astronomy.

One of these is gravitational time dilation which shows that time runs differently at different places. Let us try to understand. For example, clocks would run slow in a place with higher gravitational force. Gravitational force is a force exerted by a celestial body to pull things towards itself. This force can be different in different parts of the universe. This means that if a marble is dropped each from earth, earth’s moon and Jupiter, from the same height, it would reach the ground at different times. Why? Because of different gravitational forces exerted by earth, earth’ moon (lesser than the earth) and Jupiter (more than the earth) respectively. Gravitational pull is maximum in a blackhole which even pulls lights towards itself. Similarly, a common event will have a different elapsed time as observed by two sets of people based in places with different gravitational force. This time difference is known as gravitational time dilation. Gravitational time dilation allows for the possibility for someone to travel back in time or in the future.

The fascination of time travel has allowed Hollywood to create some mind-boggling movies around this theme including the hugely popular ‘Back-to-the Future’ series. The latest in this is Christopher Nolan’s Interstellar where time travel helps a father travel back in time to help his daughter find a scientific solution which would save the human race from extinction.

While the concepts and theories provide a scientific possibility for time-travel, we still are looking for the event when this becomes a reality!