WASHINGTON Mercury atoms keep better time than cesium atoms.
That's what physicists found when they built an experimental atomic clock based on a single mercury atom. Researchers at the National Institute of Standards and Technology (NIST) said the experimental clock is five times more accurate than the national clock, which is based on a "fountain" of cesium atoms.
Their results were pubished Friday in the July 14 issue of Physical Letters Review.
The experimental clock, an improvement over the original demonstrated by NIST in 2000, measured the natural oscillations of an electrically-charged mercury ion held in a super-cold electromagnetic trap.
The technique produced "ticks" at optical frequencies. Those optical frequencies are much higher than the microwave frequencies measured in cesium atoms. The researchers said the improvements were based on better understanding of the systemic perturbations in the mercury clock.
"They can be controlled, and we know their uncertainties," NIST physicist Jim Bergquist, the principal investigator, said in a statement.
The current cesium-based national clock would lose or gain a second in about 70 million years if operated continuously. The latest version of the mercury-based atomic clock would neither gain nor lose a second in about 400 million years of continuous operation, the NIST researchers claimed.
There goes your last excuse for being late for a meeting.