Special Relativity Clocks

Clocks and time are not the same thing. Time is a property of nature observable as changes. Day turns to night,
night turns to day, and the seasons change. Clocks are devices that measure time.

The most common type of clock is the mechanical clock. It is a device that measures time by counting the number of oscillations of a pendulum. The pendulum is suspended from a fixed point and swings back and forth.