U.S. scientists claim world's most accurate clock

Researchers build the most accurate clock in the world. This atomic clock varies from less than one second in 13.8 billion years, the estimated age of the Universe. American physicists announced Thursday the world's most accurate atomic clock experimental able to vary from less than one second in 13.8 billion years. This clock works with ytterbium atoms, a rare earth element and lasers to a regular beat of ten times higher than the best existing atomic clocks. Compared to a quartz watch, the new clock is ten billion times more accurate. This breakthrough in physics has important potential implications not only for the precision in the measurement of universal time but also GPS and a set of sensors of different forces such as gravity, magnetic field and temperature etc. Andrew Ludlow, a physicist at the National Institute of Standards and Technology (NIST) and one of the main co-authors of this work appeared in the journal Science. "This is an important step in the development of atomic clocks for the next generation currently under development in the world," he says. Like all clocks, atomic clocks keep time measurement based on the duration of a second corresponding to a physical phenomenon that occurs often. While mechanical clocks use the motion of a pendulum to keep time, atomic clocks are based on the ever-constant frequency of light needed to excite an atom of cesium, the current international reference. The last born of atomic clocks based on some 10,000 ytterbium atoms cooled slightly above absolute zero. These atoms are trapped in wells formed optical laser beam. Another laser "bat" 518.000 billion times per second creating a transition between two energy levels in the atoms that provides vibration even greater regularity than a cesium atom and could lead to a new international definition the second time and therefore universal.