cesium fountain clock

A cesium fountain clock is an extremely precise timekeeping device that uses atoms of cesium. It works by cooling cesium atoms with lasers and then launching them upward in a fountain-like motion. As the atoms move, microwaves interact with them at a specific frequency, causing a measurable change in their energy states. By tuning the microwave frequency to match this natural transition, the clock can maintain an incredibly accurate measurement of time, with deviations of less than a second over millions of years. This precision is essential for global navigation, telecommunications, and scientific research.