A centimeter of time: Cryogenic clocks pave the way to new measurements

We all like to know our watches keep the time well, but Hidetoshi Katori, of RIKEN's Quantum Metrology Laboratory and the University of Tokyo's Graduate School of Engineering, is taking precision to an entirely new dimension. In work published in Nature Photonics, Katori's group demonstrated two cryogenically cooled optical lattice clocks that can be synchronized to a tremendous one part in 2.0 x 10-18--meaning that they would only go out of synch by a second in 16 billion years. This is nearly ...