One of the key reasons smartwatches are making traditional watches obsolete is their accuracy, as they constantly synchronize with atomic clocks. Currently deployed atomic clocks using cesium atoms to absorb microwaves can measure time accurately to within one second over a 300-million-year period. The Chinese scientists are using atomic clock technology that is able to run for 30 billion years with only one second of deviation. This means the Chinese technology could run 100 times longer than the technology using cesium atoms while matching its accuracy. Creating precise timekeeping is a complicated process that has relied on atomic clocks since the 1960s, technology that measures the quantum characteristics of the nuclei of atoms.