One of the biggest challenges in modern physics is uniting quantum mechanics and general relativity. A new experiment may ...

Scientists propose using quantum-entangled clocks to test how gravity affects quantum mechanics in curved spacetime.

Optical clocks are typically evaluated on two levels — accuracy (how close a clock comes to measuring the ideal “true” time, ...

Possibly originating with the English poet Geoffrey Chaucer's "time and tide wait for no man," the idea that time waits for ...

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