Scientists report world’s first working nuclear clocks

In two papers in Nature, scientists from Europe and China have now reported the world’s first working nuclear clocks. While teams from Beijing and Shanghai embedded thorium-229 nuclei in calcium fluoride crystals and fired an ultraviolet laser at them, the effort from Austria, the Czech Republic, and Germany realised a similar nuclear clock and used it to look for dark matter.

Atomic clocks are the world’s gold standard for timekeeping, at the heart of everything from GPS navigation to synchronised networks. A ytterbium atomic clock is so precise it misses one second every 23 billion years. Yet scientists are interested in... [2390 chars]