Atomic clocks, combined with precise astronomical measurements, have revealed that the length of a day is suddenly getting longer, and scientists don't know why. Using radio telescopes observing ...

What is the simplest, most fundamental clock? Physicist Holger Müller and his UC Berkeley colleagues have shown that a single atom is sufficient to measure time using its high-frequency matter wave.

There are significantly different architectures for what are known as “atomic” clocks. Optically driven atomic clocks offer a new set of performance attributes. The optical atomic clocks use paired ...