The most precise clocks ever built are now testing Einstein, hunting dark matter, and reshaping how we define time itself. The world’s most precise clocks are changing how we understand time itself: ...

For decades, atomic clocks have provided the most stable means of timekeeping. They measure time by oscillating in step with the resonant frequency of atoms, a method so accurate that it serves as the ...

Time is almost up on the way we track each second of the day, with optical atomic clocks set to redefine the way the world measures one second in the near future. Researchers from Adelaide University ...

To find out how clock accuracy is verified and which reference is used for comparison, we visited the Belarusian State Institute of Metrology (BelGIM), where most of the national standards are kept.

As if timekeeping in the U.S. wasn’t already pretty accurate, the U.S. Department of Commerce’s National Institute of Standards and Technology (NIST) just declared a new atomic clock, the NIST-F2, to ...

This is the third time that the clock has been moved closer to midnight in the past five years. “Every second counts, and we are running out of time. It is a hard truth, but this is our reality,” ...