We normally think of atomic clocks as the gold standard in ... the two hyperfine levels of the ground state of a stationary cesium-133 atom at a temperature of 0K. But there is a move to replace ...

Now a Japanese company has commercialized one approach—an optical-lattice clock it claims is the most accurate on the market.

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 ...

Water clocks, which appeared around 2,000BC ... "The second… is defined by taking the… transition frequency of the caesium-133 atom, to be 9192631770 when expressed in the unit Hz, which ...

Symmetricom has squeezed an atomic clock into 17cm3. Called the SA.45s, the cesium atom-based device is 40x35x12mm and weighs 35g. Over the -10 to 70°C operating temperature range, frequency change is ...

In 2001, Japanese physicist Hidetoshi Katori proposed a new type of atomic clock that only loses a second every 30 billion years, a period longer than the current age of the universe. The ...