Zeptosecond

A zeptosecond is one of the smallest measurements of time. Zeptoseconds are mainly used in the propagation of light within a molecule. Or as stated by LiveScience in "Meet the zeptosecond, the shortest unit of time ever measured," "A zeptosecond is a trillionth of a billionth of a second, or a decimal point followed by 20 zeroes and a 1." (.000000000000000000001).

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Meet the zeptosecond, the shortest unit of time ever measured