Q. Measure of elapsed period using the SI unit?

Answer:-

1. This is the question that each true scientist dreads to be asked especially in a public setting by extremely inquisitive young students. We have learned to measure as well as calculate it relative to the natural arrangement of known and visible celestial bodies. To this day time can merely be described by the measure of elapsed period using the SI unit Seconds. It is the merely SI unit that is freely allowed to shift depending on subject topic. For instance in Astro physics to measure distance between galaxies it would be impractical to use seconds as the measure of time it takes light to travel between the two galaxies

Time transcends all known to man up to and including the universe time has no beginning or end. Time is constant and infinite and we just tap in and out of it in reference to occurrence of an event.