On a big desk draped with a whole bunch of cables, a maze of mirrors and lenses bounces and guides a skinny beam of laser gentle. It culminates at a silvery capsule, which holds 40,000 strontium atoms cooled to inside a whisker of absolute zero. This delicate edifice is an optical clock, one of many world’s most correct timepieces.
Devices like this aren’t precisely designed to be moveable – which makes it greater than slightly shocking that the operators of 1 such system on the German nationwide metrology institute packed it right into a trailer and despatched it hurtling down a motorway. It was the beginning of a deadly journey: a foul jolt may disrupt the beat of its exact ticks. However it was needed.
That was as a result of, in 2022, scientists globally agreed that we should always begin work on redefining the second based mostly on our newest and biggest timekeeping expertise: optical clocks. Nonetheless, this meant bringing collectively a number of of the world’s greatest specimens for comparability.
Doing so proved an enormous problem, however it’s going to absolutely be well worth the bother. A brand new definition of the second can be profoundly consequential for almost each different measurement that scientists use to explain nature, from speeds to lots and extra. Our efforts to outline it extra exactly, then, will ripple out throughout our whole view of the world. “This was the primary international comparability…
