Ralf Röhlsberger

Physicists excited scandium-45 nuclei with an X-ray laser and saw that in a solid crystal, vibrations hinder ideal precision. But the transition's natural purity promises nuclear clocks with an error of less than a second over the age of the universe. This opens the door to ultra-precise measurement

Take a clock to the second floor and you'll make it run fast — gravity slows time. Scientists have developed a method that uses iron-57 nuclei as supersensitive metronomes: by shining X-rays on them, they turn a tiny frequency shift into a glaring rhythm discrepancy. Within hours, the method sees Ei