Newton's views dominated ideas of space and time for over 200 years. Newton viewed as a rigid, empty, receptacle for matter to move in. At each point of space, a clock could be placed, and time would pass at the same rate for all the clocks, so that once synchronised, they would stay synchrinuised forever.

Einstein special theory of relativity changed all that. Space and time became a unified concept – spacetime. A concesequence of this new theory was that time became plasticised. The faster a person or object appeared to move, the slower time appeared to move for that person or object according to any observer.

The time dilation equation isIn this equationis the speed of the moving object or person, andis the time period recorded by that moving object or person.is the corresponding time period as recorded by a stationary observer.

Velocity, being relative, each pesron observing the other can consider himself stationary, and the other person moving with a speed v, so each person will see time for the other person slowing down by a factor