“Is Time Travel possible ?” Author :(Compiled by) Ponnu Elizabeth Mathew, in the New Indian Express,dated 19 th, October, 2007. Abstract By : Rabasure, in 600 words. When we proceed to examine the words and ask a question, ‘what is meant by ‘Time Travel’?’, we can say that it is going forward and backwards, to different points in time, similar to moving and traveling in a spaceship. Also we can say, ‘Time travel is possible’ and no longer the question is confined to myths, science fiction, Hollywood movies or speculations by theoretical physicists. Generally, an object traveling at a high speed ages more slowly than a stationary object. Suppose, if we travel into outer space and return, at par with the speed of light, we can travel thousands of years into Earth’s future. Einstein contributed to the study of time, by evolving and announcing his special “Theory of Relativity” in physics. This famous theory of relativity showed how time changes with motion and most importantly he proposed that the measured interval between two events depend upon how the observer is moving. When two observers move differently will experience different durations, between the same two events. The above aspect of the theory and its effect is illustrated and explained by the following episode called ‘theTwin Paradox’. Suppose that ‘Sally’ and ‘Sam’ are the twins and same age, while ‘Sally’ travels in a rocket to a nearby star at a high speed and ‘Sam’ staying back at home, and when ‘Sally’ returns to the earth after one year travel in the spaceship, she finds 10 years have elapsed and her twin brother ‘Sam’ is 9 years older than her, though ‘Sally’ and ‘Sam’ are twins by birth and of the same age. This example illustrates a limited type of travel time. The effect is ‘Sally’ has leaped nine years into earth’s future. Though we could prove theoretically, but practically, the situation is dubious. The profound result of Einstein’s special ‘Theory of Relativity’ is ‘No material object can travel as fast as light.
’ But Stephen Hawkins conjectured that we are not awash in thousands of time travelers from the future and so the time travel is impossible. If one moves close to the speed of light or sit in a strong gravitational field, he experiences time more slowly than others. i.e one travels into their future. Traveling forward in time is easy, according to the principles of science. But traveling backwards in time, into the past is rather tricky. ‘Grandfather paradox’ lays down that time travel into the past is impossible. Let us illustrate the point by ‘Grandfather paradox’. Suppose a man travels into the past and killed his biological grandfather, before the latter met the traveler’s grandmother. As a result one of the traveler’s parents, and by execution, the traveler himself would never have been conceived. This would imply that he could not have traveled back in time after all, which in turn implies that grandfather would still be alive and the traveler would have been conceived allowing him to travel back in time and kill his grandfather. Thus each possibility seems to imply its own negation, which is a type of logical paradox. And then the following questions need to be answered. ‘Whether time is real?’ ‘Whether time flows from one direction only?’ ‘Whether the time has a beginning or end?’ ‘What is eternity?’ None of these questions can be answered to the scientists’ satisfaction. However, by asking these questions, stretches one’s mind, as the continual search for answers to the above said questions provides, very useful insights into time travel.