Even your Macbook or smartphone displays time which is synchronized to the NIST-F1 clock, a cesium fountain atomic clock (aka ... Western Union office once per hour at the ‘top of the hour ...

With access to a 10-MHz timebase from a cesium fountain atomic clock — no less a clock than the one that’s used to define the SI second, by the way — [Daniel] looked for ways to sync the ...

HIROSHIMA--Passed down from his grandfather, a U.S.-made wooden clock that hangs on a living room wall at Eiji Koizumi’s home here has stood the test of time and an atomic bomb blast. The ...