A new atomic clock is one of the world’s best timekeepers, researchers say — and after years of development, the “fountain”-style clock is now in use helping keep official U.S. time. Known as NIST-F4, ...

For decades, atomic clocks have provided the most stable means of timekeeping. They measure time by oscillating in step with the resonant frequency of atoms, a method so accurate that it serves as the ...

At the dawn of the nuclear age, scientists created the Doomsday Clock as a symbolic representation of how close humanity is to destroying the world. On Tuesday, nearly eight decades later, the clock ...

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 ...