A test using atomic clocks will watch superpositions ride Earth’s curved space-time and see if Einstein can play nice with ...

Scientists in the U.S. have built the most accurate clock in the world—so precise it can measure time down to 19 decimal ...

Jacobson/NIST After two decades of tinkering, scientists at NIST have unveiled the world’s most accurate atomic clock, a ...

Einstein’s theory of relativity shows us that time isn’t constant,it stretches or contracts based on speed and gravity. But ...

The mind-bending concept of time dilation results from a seemingly harmless assumption—that the speed of light is the same for all observers.

If, like me, you can't go a day without making sure your watch is synced to the second, you'll be delighted to learn that a ...

The nodes in a quantum network don’t necessarily have to be computers; they can also be atomic clocks. The cesium atoms that ...