The first ticking ‘nuclear clocks’ are here — what can they do?

Two research teams have developed the first ticking nuclear clocks, a long-awaited advancement in timekeeping technology, as reported by Nature on June 22, 2026. These clocks leverage the precise energy transitions within atomic nuclei to measure time, offering unprecedented accuracy compared to existing atomic clocks. The development promises to revolutionize fields requiring extreme precision, such as fundamental physics research, navigation systems, and potentially even the detection of dark matter. One team, led by researchers at the National Institute of Standards and Technology (NIST), utilized a Thorium-229 isotope, which has an exceptionally low energy nuclear transition. The other team, from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), also focused on the Thorium-229 nucleus. The accuracy of these nuclear clocks is expected to be orders of magnitude greater than current atomic clocks, which are based on electron transitions. This enhanced precision could enable scientists to test fundamental physical theories with greater rigor, including Einstein's theory of general relativity, by observing subtle changes in spacetime. Furthermore, the sensitivity of nuclear clocks might allow for the detection of phenomena that are currently unobservable, such as variations in fundamental constants or the presence of exotic particles. The practical applications extend to improving the accuracy of global navigation satellite systems (GNSS) and developing more sensitive geophysical sensors for earthquake prediction or resource exploration. The researchers anticipate that further refinement of these nuclear clocks will lead to even greater stability and portability, paving the way for their integration into a wider range of scientific and technological applications.