But the excitement was running high when the clock, dubbed NIST F-1, was introduced. In development for four years, the cesium atomic fountain clock is designed to keep time accurately to within a second's loss or gain in 20 million years, compared with the older clock, which loses one second in 3 million years, the scientists said. In Synch With Other Clock Institute spokesman Fred McGehan said the lab put the clock in operation after it successfully delivered data to the Paris-based International Bureau of Weights and Measures, where the only other clock of its kind is located. It had nothing to do with New Year's Eve or Y2K concerns, he said. Old and new clocks will run simultaneously for about six months as a precautionary measure, he said.
Atomic clocks keep time by precisely counting the vibrations of atoms.
The first version was invented in 1949 with the help of physicists who worked on the Manhattan Project. It uses lasers to cool cesium atoms, which form a ball. McGehan said lasers then toss the atoms into the air, much like one would toss a tennis ball, creating a fountain effect. The observations of atoms, which are done by computers, create more accurate data to be sent to the Paris bureau where it is combined with other atomic clock data to develop the standard Coordinated Universal Time, the official world time, McGehan said. Copyright 1999 The Associated Press.