New atomic clock is most precise yet
Next test is whether the timepiece can translate precision into long-term accuracy
GRID’S GOT RHYTHM The world’s most precise timepiece consists of strontium atoms in a grid, ticking off oscillations of laser light trillions of times per second.
The Ye group and Steve Burrows/JILA
A new model of atomic clock is now the world’s steadiest metronome, with a tick rate about six times more precise than the previous record-holder.
This souped-up clock is an optical lattice — it measures time by counting the oscillations of light in a laser beam, which happen about 430 trillion times per second. Strontium atoms in the clock tick off each oscillation by absorbing and re-emitting this light.
Previous optical lattices held strontium atoms in a queue of pancake-shaped gas clouds, where atoms were liable to bump into each other, which could make them lose their rhythm (SN: 10/22/11, p. 22). That limited the precision of the clock’s measurements.
In the new clock, described in the Oct. 6 Science, researchers meticulously assembled atoms in a gridlike structure — like eggs in
