We all love a watch that keeps good time - so why not go for the best? An atomic clock.
Atomic clocks are typically housed in government facilities and because they're the most accurate measures of time, they're used to keep navigational GPS systems accurate and to control the wave frequency of television broadcasts. If you have an atomic clock at home, it probably doesn't contain the necessarily cesium gas or mechanisms inside, but is most likely connected via a radio signal to a clock at a government institution.
New Atomic Clock Redefines Time
But now Bathys Hawaii, a maker of higher-end diver's and sports watches, has built an atomic watch you can wear on your wrist. Called the Cesium 133, the watch is extremely accurate; it loses only a second once every 1,000 years.
The watch works the same way the government's atomic clocks do. Cesium is heated and passes through a vacuum tube surrounded first by a magnetic field and then by a microwave field. The microwaves make the cesium atoms change their energy states. When they do that, they emit signals at a very specific frequency.