Vienna researchers build prototype nuclear clock

A self-stabilizing thorium-based timekeeper achieves unprecedented precision but remains a lab prototype

Vienna University of Technology and PTB Braunschweig developed a prototype nuclear clock using thorium nuclei that achieves a relative precision of 10^-15—equivalent to an error of one second over 30 million years. The clock self-regulates laser frequency through thorium nuclei without external atomic clock intervention, with key milestones in April and fall 2024. However, it remains less precise than world-leading optical atomic clocks and is based on a single-day test, not long-term performance. Thorium nuclei—not the entire atom—serve as the timekeeping reference. This prototype could improve GPS accuracy (MOBILITY), financial systems, and infrastructure resilience (SECURITY) if scaled, but current precision and stability fall short of real-world deployment. The source reports this October 2026, but the clock’s practical impact remains unproven at scale. This is a brief source; full details sit with the researchers.

Source: ScienceDaily