The most precise clocks ever built are now testing Einstein, hunting dark matter, and reshaping how we define time itself. In ...

Determining the passage of time in our world of ticking clocks and oscillating pendulums is a simple case of counting the seconds between 'then' and 'now'. Down at the quantum scale of buzzing ...

The new Doomsday Clock time has been set by the Bulletin of the Atomic Scientists. Here’s what it means.

Researchers at the UK’s National Physical Laboratory (NPL) have created a tiny atomic fountain ...

This has now paved the way for a multi-ion optical ytterbium clock that combines the high accuracy of single-ion clocks with ...

Add Yahoo as a preferred source to see more of our stories on Google. MIT and Harvard scientists have built the world’s most precise optical clock, surpassing the quantum limit with entangled atoms ...

The white pickup truck pulls up to a decommissioned space observatory on top of Mount Blue Sky, one of Colorado’s famous “14ers,” mountains that reach more than 14,000 feet high. The scene is stark on ...

For many years, cesium atomic clocks have been reliably keeping time around the world. But the future belongs to even more accurate clocks: optical atomic clocks. In a few years' time, they could ...