What is Atomic dock?

Atomic clock is a device for measuring time. It makes precise measurements of time. It makes use of the vibration of atoms or molecules, instead of quartz crystals or a coiled spring which are used in quartz and mechanical watches respectively, to measure time.

The most commonly used atoms and molecules in atomic clocks include caesium atoms, hydrogen atoms and molecules of ammonia gas. Atomic clocks based on rubidium atoms instead of caesium are now in use. Some atomic clocks gain or lose no more than a second in 200,000 years. These are used to keep time in laboratories and observatories.