Give an example from classical physics in which the motion of a clock affects its rate-that is the way it runs. (The magnitude of the effect may depend on the detailed nature of the clock.)

The first exposure to the relativity of simultaneity, the apparent shrinking of moving rods, and the slowing down of time may be disturbing. However, a bit of thought will persuade you that the classical alternatives are even more disturbing. For example, a classical rigid rod of definite length is not a concept that is consistent with relativity; a signal (say, a quick movement) at one end cannot be transmitted instantly to the other end. We must give up the idea of all observers being able to use the same measuring rod. We replace this idea with one that gives each observer a measuring rod and permits that observer to use that rod to make measurements within a particular frame of reference.