Story perspectives

Austrian and Chinese teams build first operating thorium-229 clocks

By Drooid · Oct 10, 2026, 1:16 AM UTC · How we work

Summary

Story summary

Austrian and Chinese teams built the world’s first operating thorium-229 nuclear clocks.
The prototypes were reported in Nature on October 7, 2026.
Vienna’s clock drifts about one second per 30 million years.
Beijing’s clock is roughly six times more stable than Vienna’s.
Researchers cite navigation, data synchronization, geophysical surveys, and physics research as potential applications.

History

Historical Context

Louis Essen built the first practical cesium-133 clock in 1955, and the U.S. National Bureau of Standards (later NIST) refined cesium fountains to the NIST-F2 standard with 1 × 10?¹6 uncertainty. Building on that legacy, Chinese researchers at Vienna University and the Chinese Academy of Sciences unveiled thorium-229 clocks drifting only one second in 30 million years, far exceeding the 1969 cesium benchmark and enabling sub-nanosecond timing for networks.

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Story summary

Austrian and Chinese teams built the world’s first operating thorium-229 nuclear clocks.
The prototypes were reported in Nature on October 7, 2026.
Vienna’s clock drifts about one second per 30 million years.
Beijing’s clock is roughly six times more stable than Vienna’s.
Researchers cite navigation, data synchronization, geophysical surveys, and physics research as potential applications.

1 / 2