cesium 133

noun

: an isotope of cesium used especially in atomic clocks and one of whose atomic transitions is used as a scientific time standard

Examples of cesium 133 in a Sentence

Recent Examples on the Web The official length of the basic unit, the second, was fixed at 9,192,631,770 vibrations of an atom of cesium 133. Alanna Mitchell, New York Times, 14 Nov. 2022 But improving upon the cesium 133 atom comes with improvements in our laser capabilities. Tim Newcomb, Popular Mechanics, 26 Apr. 2022 Since 1967, the second has been defined by the cesium 133 atom. Tim Newcomb, Popular Mechanics, 26 Apr. 2022 In the case of cesium 133, the frequency is nearly 9.2 billion ticks per second — 9,192,631,770, to be precise. New York Times, 25 Apr. 2022

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'cesium 133.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1964, in the meaning defined above

Time Traveler
The first known use of cesium 133 was in 1964

Dictionary Entries Near cesium 133

Cite this Entry

“Cesium 133.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cesium%20133. Accessed 25 May. 2024.

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