An unprecedented optical clock network lays the groundwork for redefining the second. An npldigital team conducted the largest coordinated comparison of optical clocks to date by operating clocks and the links connecting them simultaneously across thousands of kilometers. To perform the measurements, the researchers linked the frequency outputs of various optical clock systems. They achieved this using two methods: radio signals transmitted from satellites and laser light traveling through optical fibers. #OPG_Optica #opticalclocks #scienceandtechnology