In Vienna and Beijing, the first nuclear clocks have begun to tick, using thorium-229 nuclei to keep time by counting nuclear isomer transitions. These clocks lose only one second every few million years and represent a major breakthrough in precision timekeeping. Though not yet surpassing atomic clocks in reliability, they offer potential advantages in portability and dark matter detection.
Experts like Eric Hudson and Elina Fuchs praise the work as a significant milestone. The clocks function by shining ultraviolet lasers on thorium-229 nuclei, causing them to shift between squished and unsquished states. This achievement follows a two-decade effort to isolate thorium-229’s resonant frequency at 148 nanometers.
Teams overcame challenges including the isotope’s scarcity and the lack of suitable lasers. The research, published in Nature, marks a key step toward nuclear clocks becoming practical tools for fundamental physics and future timekeeping standards.
Source: Hacker News · Summarized by HeadlinesBriefing