First Accurate Atomic Clock

 

On this day in 1955, Louis Essen and Jack Parry, at the National Physical Laboratory in the UK, invented the first accurate Caesium-133 atomic clock. It was capable of accurately recording time to the second, falling behind only one second every for an estimated 300 years. The atomic clock is simply a laboratory apparatus that keeps time. In 1945, Columbia University physics professor Isidor Rabi suggested that a clock could be made from a technique he developed in the 1930s called atomic beam magnetic resonance. Modern atomic clocks, like the NIST-F2, invented by the National Institute of Standards and Technology, Boulder, Colorado, are capable of telling the accurate time down to the second for an estimated 100 million years. Close enough.

Brainiac details HERE