Optical Atomic Clock

Scientists unveil lutetium optical clock accurate to 260 billion years

Physicists have built an optical atomic clock based on the rare-earth element lutetium that would drift by less than one second over roughly 260 billion years, making it the most precise timekeeper reported so far. The clock measures time using the frequency of visible light absorbed by lutetium atoms. Researchers say its design is stable enough that they aim to miniaturize it for use outside the laboratory.

nature.com · 2026-09-24

NUS physicists build lutetium atomic clock accurate to 260 billion years

Researchers at the National University of Singapore have built an optical atomic clock using lutetium ions that is four times more precise than the previous record-holder, a calcium-ion clock. The device would lose less than a second over roughly 260 billion years, making it the most accurate timekeeper reported to date, according to a study published in Nature on September 23.

nature.com · 2026-09-23