Optical atomic clocks are our most precise tools to measure time and frequency 1–3 . Precision frequency comparisons between clocks in separate locations enable one to probe the space–time variation ...

Here on Earth, it might not matter if your wristwatch runs a few seconds slow. But crucial spacecraft functions need accuracy down to one billionth of a second or less. Navigating with GPS, for ...

To keep atomic clocks and those based on the earth’s rotation in sync, GCWM periodically adds a second to UTC; the prospect of having to subtract one, potentially causing major disruption, is ...

In a network containing multiple nodes, the need for synchronization between the various nodes is not just instrumental but also a complicated and highly complex process. This process becomes even ...