Science Daily reported today that physicists at the National Institute of Standards and Technology (NIST) have built the world’s most precise clock. The new clock would neither gain, nor lose, one second in about 3.7 billion years according to results in the soon-to-be-published report in Physical Review Letters.
The new atomic clock is based on a “single aluminum ion trapped by electric fields and vibrating at ultraviolet light frequencies” and is “more than twice as precise as the previous pacesetter based on a mercury atom.” These “optical clocks,” (so-called because their atoms oscillate at frequencies of light rather than in the microwave band) divide time into smaller units, allowing for more precision than the cesium atom-based “fountain clock,” that provides the current internationally recognized standard definition of the second.
While aluminum is certainly one contender for a future time standard to be selected by the international community, NIST scientists are also experimenting with a number of optical clocks, each “based on different atoms and offering different advantages.” More: [Science Daily]
