Singapore Researchers Unveil Lutetium Clock with Record 10^-19 Accuracy
Researchers at the National University of Singapore (NUS) have developed the world’s most accurate atomic clock, utilizing the rare-earth element lutetium. Published in Nature on September 23, 2026, the device achieves an uncertainty of 1 x 10^-19, meaning it would take over 260 billion years to lose a second. This optical clock is four times more precise than the previous record-holder based on calcium ions. The team verified its accuracy by comparing two independent clocks, which agreed to the 19th decimal place. The breakthrough, resulting from over a decade of work, could lead to a redefinition of the second and enable ultra-precise gravity mapping.