Clocks on Earth are ticking a bit more regularly thanks to NIST-F4, a new atomic clock at the National Institute of Standards ...

We normally think of atomic clocks ... state of a stationary cesium-133 atom at a temperature of 0K. But there is a move to replace that definition using optical clocks that are 100 times more ...

Whether you find yourself glancing at a clock on the wall or checking your phone, the time you constantly see is the product of a meticulous system upheld by the world’s timekeepers. In the U.S., a ...