Quote:
Originally Posted by Mark Padgett
Although cultures have used hours to denote the passage of time for hundreds of years, the "second" is considered to be a metric unit.
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It is also an English unit (foot-pound-second).
And the French don't define it, nature does. The second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.