How Do Clocks Keep Accurate Time?

Imagine a clock as a very careful dancer, it moves in perfect rhythm to keep time. Some clocks use pendulums that swing back and forth, while others count the number of vibrations from tiny pieces inside them. These little dancers help the clock stay on track so we know when to wake up or go to bed.

A pendulum swings at a steady rate, like a metronome in music class. A quartz crystal vibrates very fast, about 32,768 times every second. These vibrations are counted by the clock's brain so it can keep time precisely.

When your clock is accurate, you know when to catch the bus or start dinner. Some clocks, like atomic clocks, use even more precise dancers, atoms that vibrate at an incredibly steady rate, to measure time with almost no error.