One-sixtieth of a minute; the SI unit of time, defined as the duration of 9,192,631,770 periods of radiation corresponding to the transition between two hyperfine levels of caesium-133 in a ground state at a temperature of absolute zero and at rest.
One-sixtieth of a minute; the SI unit of time, defined as the duration of 9,192,631,770 periods of radiation corresponding to the transition between two hyperfine levels of caesium-133 in a ground state at a temperature of absolute zero and at rest.