Optical clock

An optical clock is a highly precise timekeeping device that uses the vibrations of light waves instead of traditional microwaves, as in standard atomic clocks. It measures the frequency of light absorbed or emitted by atoms or ions to keep time with extraordinary accuracy—so precise that it would only lose or gain a second over billions of years. Optical clocks are used in advanced science, GPS technology, and testing fundamental physics because their precision surpasses conventional clocks, enabling better synchronization and measurement at the tiniest scales.