A breakthrough in chronometry decades in the making could redefine the limits of how we keep time. Using atoms of thorium-229, physicists have built functional clocks based not on the oscillations of ...

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 ...

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.

In popular culture, lasers are often portrayed as portable blasters that superheat whatever they hit. Some lasers do deliver tremendous amounts of energy in reality, but for scientists and engineers, ...