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NASA clock could set time for universe
By Richard Stenger (CNN)
(CNN) -- Had a new atomic clock developed by NASA started ticking when the universe was young, it would have remained accurate enough today to get you to a lunch engagement on time. The time-keeping machine, engineered at NASA's Jet Propulsion Laboratory, is intended to provide more precise measurements for everything from interplanetary space navigation to the Global Positioning System satellite network. "These trapped ion clocks are designed for long-term stability, continuous operation and high reliability. Long-term time keeping is an ideal application for the technology," said JPL's Robert Tjoelker, who conducts time synchronization research for deep space navigation and radio science experiments. Long term is putting it mildly. The clock can keep time accurately to within one minute over 10 billion years, almost as long as the estimated age of the cosmos. Atomic clocks exploit the laws of modern physics to serve as astonishingly accurate timekeepers. The ions of a particular element move predictably in accordance with quantum physics, rendering them mini time-clocks, regardless of their location. "A wonder of quantum mechanics that govern the world of atoms is that every isolated atom in the universe is exactly the same as every other atom of the same element," the JPL researchers said in a statement. Predecessor atomic clocks use specially coated glass walls to catch and monitor ions inside a closed chamber. But the constant collisions can slightly alter the atomic particles and make the clocks run fast or slow over time. The JPL clock employs a new method to contain the ions -- in this case of the element mercury -- disturbing them much less as they bounce around. Rather than careen off a wall in a glass chamber, they run into an applied electrical force field that completely surrounds them, providing a much softer bounce. One of the contraptions will remain at the Pasadena, California, lab while a second will join a stable of other atomic clocks at the U.S. Naval Observatory in Washington, D.C. The observatory, which plots the movements or rotations of numerous celestial bodies, including Earth, sun and planets, supplies astronomical data to the U.S. Defense Department, the GPS satellite network and other public agencies.
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