The best timekeepers today—atomic clocks—work off the quantum vibrations of an atom, specifically its electrons. But physicists have long dreamt of even better clocks that run on atomic nuclei, which are less sensitive to environmental disturbances. According to new research, that dream might soon become reality. Last week, two independent teams based in Europe and China reported the first set of results from experiments using an atomic nuclei clock based on crystals of calcium fluoride containing thorium-229. Both papers, which have yet to be peer reviewed, are available as a preprint on arXiv. In the European experiment, researchers compared how…