atomic second

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Leonardo da Vinci (1452-1519), Italian Renaissance painter from Florence. Engraving by Cosomo Colombini (d. 1812) after a Leonardo self portrait. Ca. 1500.

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atomic second

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definition

In spectroscopy: Methods
One second is defined as the time it takes for the cesium frequency to oscillate 9,192,631,770 times. Such atomic clocks have a longer-term uncertainty in their frequency that is less than one part in 10¹³. Measurement of time intervals based on the cesium atom’s oscillations are…
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