World’s First Nuclear Clock Uses Thorium-229 to Hunt for Dark Matter
Scientists have achieved a major physics milestone by developing the world’s first functional nuclear clock; a timekeeper that uses energy transitions inside an atomic nucleus rather than electron orbits. The breakthrough, published in Nature on October 12, 2026, was led by an international team including Luca Toscani De Col from TU Wien (Vienna University of Technology). Daily News Egypt
Unlike conventional atomic clocks, which track electron behaviour, this nuclear clock embeds thorium-229 nuclei in a calcium fluoride crystal and excites them with a deep-ultraviolet laser at 148 nanometres. When the laser drifts from resonance, the nuclei’s response acts as feedback to correct it, maintaining extraordinary precision.
Running continuously for roughly 24 hours, the clock achieved a fractional frequency instability of about one part in a quadrillion. Crucially, the team compared it against a ytterbium-ion optical clock for nearly 23 hours to search for dark matter signatures; tiny oscillations in fundamental constants that certain dark matter theories predict.
While no dark matter signal was detected, the experiment set constraints on dark matter interactions 100 to 1,000 times tighter than previous limits for scenarios involving the strong nuclear force and quark masses. Researchers note that crystal inconsistencies currently limit performance, but advances in lasers and crystal quality could extend observations significantly.
The nuclear clock represents a new frontier in precision metrology and fundamental physics. Read our previous article in Science and Technology related news here.
