Concept of relativity in understanding ‘Time’

Perhaps not many have paid attention to understand what we mean by ‘Time’. We are all familiar with the practice of mentioning location while indicating time e.g. EST, GMT, IST etc. Here the ‘Time’ is reckoned with regards to relative position of Sun with respect to earth’s rotational axis. Thus in a location where the Sun is rising, the time could be 6AM while there would be locations on earth where the Sun would appear to be setting and there the time would be 6PM. An incident say an earthquake occurring in one place will be recorded to have occurred at different times depending on the relative position of earth with respect to Sun at that location. Thus across the International dateline, there will be a difference of one day. This means if the date on one side of the international dateline is 15 on which my child is born, its birthdate would be either 16 or 14 on the other side of the international dateline depending on whether you have moved towards East or towards West to cross the dateline.

Earth takes approximately 365 days to travel around the Sun, which means the position of the Earth with respect to Sun in the Solar galaxy will be the same in 365 days interval which we term as one year. Instead of taking Sun as the reference point, one can take the position of moon as reference point to ‘measure time’. Some people do follow this system and their year naturally does not match with ‘Solar Year’. A ‘lunar year’ is much shorter than a ‘Solar Year’. We can also have reference some stars for measuring time.

Another interesting question is about our understanding of ‘simultaneity’. What do we mean by saying that the events have occurred simultaneously. Imagine for a moment we are able to see another galaxy similar to our’s where there are people living. Suppose the distance of that place to our place here is such that it takes one year for light to travel to cover the distance. If a child is born at this time today, we can see the birth of the child only after one year since the light would take one year to travel. Thus if we are celebrating the birth of a child here now, in some other place the child would be either one year old or will be born one year later. What it means is that in the absolute terms no two events can be termed as having occurred simultaneously based on our visual observation.

These questions then lead us to realm of metaphysics – what we see is really true or is it just an illusion. If it is an illusion then what is truth. Ancient Philosophers meditated a lot to find answers to these questions. Science perhaps tried to explain this  phenomenon through theory of relativity and to me it has been interesting to observe how Science and Philosophy merged at this point.