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 ...

Since 1947 -- after the end of World War II and at the beginning of the Cold War -- the Science and Security Board of the Bulletin of Atomic Scientists have kept what they call a "Doomsday Clock." ...

For centuries, time was tied to Earth’s rotation, with a second defined as a fraction of a full day. But inconsistencies in the planet’s spin made that system unreliable for scientific use. Since 1967 ...

Unlike other atoms (left), ytterbium-173 (right) has a large nuclear spin and a strongly deformed nucleus whose strong fields interact with the electron shell. This turns forbidden quantum jumps into ...

Smaller version Illustration of a conventional atomic fountain clock (left) next to NPL’s miniature atomic fountain clock. (Courtesy: NPL) A miniature version of an atomic fountain clock has been ...