Time and space has fascinated man for many a century. The earliest recorded ideas on philosophy of time goes to the Egyptian philosopher Ptahhotep who is supposed to have lived from 2650 to 2600 BC. The ancient Indian and Hindu Texts also about the same time have given their own interpretation of time..As per the Vedas the universe goes through a cycle of creation and destruction in a periodical manner. As per the Vedas this cycle results in creation, death and rebirth and each cycle is supposed to last 4,320,000. Later Greek philosophers also gave their own interpretations of time.But not many philosophers touched the idea of space.. Very few saw a relationship between space and time.
Modern scientists have found relation between space and time. Starting from Newton to Max Plank a definite relationship is supposed to exist between time and space. However it was Einstein who integrated the two in his theory of Relativity and Special theory of Relativity. As per Einstein time and space could be plotted on a graph and theoretically could be traversed in any direction. Thus as per philosophers it was possible to travel back in time as well and this spawned a number of books of fiction on the subject as well. The most famous being 'the time machine' by HG wells.
Einstein advocated a 4 dimensional universe. This was a revolutionary concept as all along from the Greek philosophersthe concept of time and space was 3 dimensional. Einstein added a fourth coordinate time. Einstein also put a limitation to the speed that could be achieved in any medium and that was the speed of light, which was constant in all mediums.
Modern theory of space and time is greatly derived from the concepts of Einstein and to a certain extant Max Plank. Modern thought points to the fact that though time has a direction but there is no practical time reversal. Though theoretically you could see a movie from the beginning or start seeing from the end, yet in real terms the direction of time is one way. Theoretically anything that can happen moving forward through time is just as possible moving backwards in time. Or, put in another way, through the eyes of physics, there will be no distinction, in terms of possibility, between what happens in a movie if the film is run forward, or if the film is run backwards. However our experience of time, at almost all levels shows that time-reversal is not possible. An object may break and fall to pieces on the ground, but the reverse does not happen as the pieces do not fly back and become one again.
The study of time and space may yet lead to exciting possibilities. We can keep our fingers crossed.