A maze of mirrors and lenses bounces back onto a large table covered with hundreds of cables, leading to a thin beam of laser light. It reaches its peak with a silver capsule. This holds 40,000 strontium atoms cooled in an absolute zero whisker. This delicate building is an optical clock, one of the most accurate clocks in the world.
Such instruments are not designed precisely to be portable. This makes it a little surprising that one operator of such devices at the German National Institute of Metology stuffed them into a trailer and burned the highway and sent them. It was the beginning of a dangerous journey. A bad shock can confuse that exact mites beat. But that was necessary.
That’s because in 2022, scientists agreed to begin work redefine the second based on the latest and largest timekeeping technology, the optical clock, globally. However, this meant putting together some of the best specimens in the world for comparison.
Doing so has proven to be a big challenge, but it is certainly worth the trouble. The second new definition becomes extremely important for almost every other measure scientists use to describe nature, from speed to the masses. Our efforts to define it more accurately will ripple through the overall view of the world. “This was the first global comparison…
Source: www.newscientist.com