Travelling from 1972 to 1942 or travelling from 2009 to 2042 just like travelling from New York to Washington DC. A lot of street plays and cinemas such as ‘Back to the Future’ have built a lot of plots that revolve around time traveller moving from one time zone to the other. Is it really possible? If yes then, how?
The idea revolves around relative time experience of two travellers one who stays back on the earth and the other who travells inside a space craft at nearly the speed of light. The theory suggests that the time experienced by the traveller would be different from the time experienced by the person on the Earth. So in effect the person who experiences 50 years on the space craft will see that 400 years have elapsed on the surface of the Earth. So in essence he has travelled time or has travelled to the future. (Time dilation)
The assumption that is questionable in this theory is whether aging which is caused by meta physical phenomena will also be influenced by time dilation or whether time itself is more universal as per which a person will age rather than relative time which causes a persons motion into the future.
Atomic clocks have shown to experience time dilation when one is accelerated to near light speed. So can one travel to the past?. Travelling to the past is unlikely as it will affect the principle of causation. This is the famous Grandfather paradox where a traveller when he travels to the past could stop his grandfather from getting married to his grandmother. In this case can he exist now? This is explained by multiple universes, a universe in which he exists now and a universe where he does not exist( where his grandad and grandmom do not get married.)
Even great yogis such as Swami Yogandanda have verified that time travel is possible as some yogis in the past have disappeared as light and reappeared after eons and ages. So what we can see in the future is that technology being developed where a traveller will remain in motion for 10 years and return to the earth after 400 years and our future human civilizations will witness time travel after all!!