Cabinet toy №4

Hold the Thorium Note

Two labs just built clocks that tick on an atomic nucleus instead of its electrons. The trick is a feedback loop: a laser is nudged, over and over, to stay on a very narrow absorption line of thorium-229 nuclei sitting in a crystal. Here, you are the loop.

The real light is 148-nanometre vacuum ultraviolet — invisible to eyes and swallowed by air. We draw it violet as a courtesy.