News Physics Physicists take a major step toward making a nuclear clock In a first, a tabletop laser nudged a thorium nucleus into a higher energy state Scientists have taken a step toward building a nuclear clock out of thorium-229. Mustapha Laatiaoui By Emily Conover April 4, 2024 at 8:00 am - More than 2 years ago Share this:Share Share via email (Opens in new window) Email Share on Facebook (Opens in new window) Facebook Share on Reddit (Opens in new window) Reddit Share on X (Opens in new window) X Print (Opens in new window) Print The time is nigh for nuclear clocks. In a first, scientists have used a tabletop laser to bump an atomic nucleus into a higher energy state.