ABSTRACT
The qualitative discussions of the last chapter made it clear that motion affects time and space. This chapter investigates these effects quantitatively and determines the extent to which motion affects the working of clocks and rulers, and addresses the question of whether we have to correct our watches or adjust our height every time we hop in and out of a car.
As Einstein said “Time is what is measured by clocks.” So, let us look at the effect of motion on clocks. And by the “effect of motion” we do not mean the effects of the bumps and puddles of a rough road which may actually damage a clock. We have in mind the smoothest possible ride such as the sailing of a spaceship in outer space. Any effect on clocks must be interpreted as an effect on time itself, although we may be using a particular clock to detect the effect.
