If the atomic clock in the University of Colorado Boulder's JILA laboratory had been started when the Earth came into existence, its time would still be perfect down to the very second today. Likewise, if the clock were reset now and kept running, it would likely outlast life on Earth. The laboratory's atomic clock is — perhaps unsurprisingly — said to be the most precise one in the world, and it's being unveiled today by a paper in Nature. But while it's an incredible feat for timekeeping, for researchers it's only one tick forward.
"We already have plans to push the performance even more."
"We already have plans to push the performance even more," Jun Ye, the research's leader, says in a statement. Ye is a fellow with the National Institute of Standards and Technology (NIST), which runs the JILA lab in partnership with CU Boulder. "Even this new Nature paper represents only a 'midterm' report," Ye says. "You can expect more new breakthroughs in our clocks in the next five to ten years."
For NIST, proving that its technology is definitively the best is an ongoing battle. Despite the fact that it should keep perfect time for 5 billion years, a technicality prevents the clock from being strictly considered the most accurate out there: it's based on the wrong element. NIST's clock uses strontium atoms, but the accepted definition of time is based on cesium atoms. NIST's hope is that it can eventually persuade the standards body to accept strontium either in addition to or in place of cesium, which gives it good reason to push forward with its work.
NIST will face plenty of competition from pioneering cesium-based clocks on the way though. While it's over an order of magnitude less accurate, one recent cesium clock from the Paris Observatory was found to be capable of staying accurate within one second for 300 million years — a major leap over other cesium clocks. Yet like NIST's clock, it too is attempting to see a change in the way a second is measured: even though it's based on cesium, it measures time in a non-standard and still unaccepted way.
A race to redefine how the second is measured
The new atomic clock from NIST takes the same type of approach. Like the Paris Observatory's atomic clock, NIST uses a powerful laser to cause a lattice of atoms to rapidly oscillate between energy levels while also detecting its frequency. Though it's a method that NIST has been using for several years now, it says that recent developments in laser stabilization and measurement precision have enabled its new atomic clock to perform far better than earlier versions.
Naturally, the development of such precise clocks is far from a matter of improving our watches. The researchers suggest that these new atomic clocks could be used to help develop incredibly precise quantity sensors for gravity and temperature, generally providing researchers with a way to measure minute quantities in more detail than ever before.