It's the physics equivalent of the trickle-down theory, of sorts. Improvements in measuring time should result in improvements in applications that rely on precise time computations, such as those used in global positioning satellite systems, telecom, and wireless networks.
A wristwatch isn't good enough for Bergquist
The National Institute of Standards and Technology this month published an article in the journal Physical Review Letter
saying it had created an experimental atomic clock using a mercury ion that's nearly five times more precise than NIST-F1, the standard national clock that the institute operates. The current national clock already is pretty good; if operated continuously, it would neither gain nor lose a full second in about 70 million years. The mercury clock takes that to 400 million years, and NIST researchers say they've made even more improvements since submitting their article.
The experimental clock measures the uninterrupted rhythms of an electrically charged mercury atom held in an ultra-cold electromagnetic trap. It ticks at frequencies much higher than the microwave frequencies measured in the national clock. That could enhance GPS systems, which rely on radio signals traveling at the speed of light from satellites that use atomic clocks.
"The accuracy of the mercury-ion system is superior to that of the best cesium clocks," NIST physicist and principal investigator Jim Bergquist says. Still, it will be at least five to 10 years before a clock using mercury will replace cesium clocks.