Clocks made from an atomic nucleus just ticked on for the first time

Researchers already used one of the nuclear clocks to search for dark matter

A translucent blue cylindrical crystal mounted on a post

A crystal of calcium fluoride that is infused with thorium atoms (shown) is at the heart of a new nuclear clock.

Luca Toscani De Col/TU Wien

For the first time, scientists used an atomic nucleus as a clock.

The world’s most precise timepieces are made using atoms, specifically their electrons.