Alone boy on Instagram: "The NIST-F4 atomic clock, developed by the National Institute of Standards and Technology (NIST), is one of the most accurate timekeeping devices ever made. If it had started running during the age of dinosaurs, it would still be accurate to within just one second today. The clock works by tracking the natural vibrations of cesium atoms. These atoms are cooled and tossed upward in a fountain-like motion. As they rise, they pass through microwave radiation, which causes t