Clock

time · inventions · everyday science

Measures time. A clock is a device that measures and shows time, especially intervals shorter than a day, month, or year.

Super old idea. The clock is one of the oldest human inventions, made because people wanted to track smaller chunks of time.

Many designs. Over thousands of years, clocks have worked using all sorts of physical processes, from shadows to swinging pendulums.

Fancy name. A very precise clock is called a chronometer, a word once used for clocks accurate enough to help sailors navigate.