The world's most accurate atomic clock based on neutral atoms has been demonstrated by physicists at JILA, a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder. The JILA strontium clock would neither gain nor lose a second in more than 200 million years. Bathed in red laser light at exactly the right frequency, strontium atoms "tick" 430 trillion times a second. Ultrahigh accuracy atomic clocks are critical for GPS navigation, s