Nuclear clocks near reality promise ultra-precise timekeeping
Physicists are closing in on a nuclear clock that would use transitions in the thorium-229 nucleus to time events, following a 2024 laser breakthrough that pinpointed the key energy transition. The remaining challenge is building a stable 148-nanometer ultraviolet laser to drive the transition. Teams across China, Europe, Japan and the US are assembling the components, with some researchers predicting initial measurements as early as 2026, which could yield a compact, noise-resistant clock that may surpass current optical atomic clocks.
