Office of Naval Research to unveil the ‘matchbox’ atomic clock: “It loses only one second every 10,000 years.. In October 2003 the Office of Naval Research will unveil the performance of the next-generation, super-accurate clock no bigger than a matchbox. The Ultra-miniature Rubidium (Rb) Atomic Clock, 40 cubic centimeters in volume and using a minuscule one watt of power, doesn’t weigh much more than a matchbox either. And… it will lose only about one second every 10,000 years.”