Scientists at the National University of Singapore have developed a highly precise optical atomic clock using lutetium. Researchers at the Centre for Quantum Technologies measured its frequency to 19 decimal places and reported an uncertainty of 1 × 10-19, which they said is the lowest recorded for an optical atomic clock. The team compared two separate clocks to test the measurement and achieved a comparison uncertainty of 5.7 × 10-19. The technology could support future research involving gravity, geophysics and fundamental physics while contributing to precision measurement and timekeeping standards. Researchers are also working toward creating a transportable version.