Nuclear-clock prototype uses its nuclei to stabilize a laser

Electronics For You reports a thorium-229 nuclear-clock experiment by TU Wien, PTB and research partners. The prototype used nuclear feedback to stabilize its laser and ran for more than 24 hours without manual intervention. Reported frequency instability near one part in a quadrillion is a stability result, not proof of absolute timing accuracy over millions of years.

DTT summary based on Electronics For You's report. The full article is on the publisher's site.