ATOMIC CLOCK

Atomic ticker clocks up 50 years.

Dr Louis Essen developed the first atomic clock 50 years ago. The time-keeping device that governs all aspects of our lives, the atomic clock, is celebrating its 50th year. The first atomic clock, which uses the resonance frequencies of atoms to keep extremely precise time, was born at the UK's National Physical Laboratory.

Atomic clocks form the standard for Coordinated Universal Time (UTC), which governs legal time-keeping globally. The clocks are vital for rafts of technologies, such as global satellite navigation, and TV signal timings. Precise and accurate time-keeping is also essential for other synchronised events, such as the distribution and management of electricity, and financial transactions across the globe.

Even London's Big Ben relies on atomic clocks to keep it right. The first accurate caesium atomic clock was developed at the NPL in 1955 by Dr Louis Essen.