The atomic clock is a timekeeping device of unparalleled precision that uses the vibration frequencies within certain atoms and molecules. The time kept by atomic clocks is now accepted as the international standard. American physicist William Frank...

The atomic clock is the most precise measurement of time that exists. The National Institute of Standards and Technology based in Boulder, Colorado houses a cesium atomic clock (so-called because it uses atoms of cesium) that is accurate to one second...

An atomic clock is a type of clock that uses an atomic resonance frequency standard to feed its counter. Early atomic clocks were masers with attached equipment. Today's best atomic frequency standards (or clocks) are based on absorption spectroscopy of...