September 2tn, 2003.

What is Atomic Time and how is it kept?

Atomic Clock is a device that measures time by the frequency of radiation emitted by an atom or molecule when it makes a transition between two energy states. Atomic clocks are extremely precise and are used to keep universal time-the international basis for establishing legal and scientific times and for setting all public and private clocks worldwide. Most atomic clocks in use today are passive cesium clocks. The United States National Bureau of Standards (NBS, now National Institute of Standards and Technology, or NIST) established the second as the time radiation would take to go through 9,192,631,770 cycles at the frequency emitted by cesium atoms making the transition from one state to another. Cesium clocks are so accurate that they will be off by only one second after running for 300 million years. The atomic clock has led to new and more precise techniques for measuring time and distance. Satellite navigation and positioning systems such as the Global Positioning System rely on atomic clocks. The U.S. National Aeronautics and Space Administration (NASA) uses atomic clocks to time its transmissions to space probes. But with the rapid pace of technology development you can have an atomic time right on your computer clock. Want to know how? Read our next article about software that synchronizes your computer clock with atomic one to display the correct current time.

Next Week. How do I get Atomic Clock on my computer?