Most clocks, from wristwatches to the systems that run GPS and the internet, work by tracking regular, repeating motions. To build a clock, you need something that ticks in a perfectly repeatable way.

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: ...

Imagine you're trying to keep time by listening to a room full of people clapping. If everyone claps randomly, it’s hard to tell the rhythm. But if they clap in sync, the beat becomes clear and steady ...

(THE CONVERSATION) Most clocks, from wristwatches to the systems that run GPS and the internet, work by tracking regular, repeating motions. To build a clock, you need something that ticks in a ...

Get any of our free daily email newsletters — news headlines, opinion, e-edition, obituaries and more. (THE CONVERSATION) Most clocks, from wristwatches to the systems that run GPS and the internet, ...