W. H. Long

Inside an atom's nucleus, protons and neutrons stack in layers, like spectators in a packed hall. When a layer is full, the nucleus becomes especially stable — physicists call these 'full rows' magic numbers. One of them, 32, has long been elusive: in nuclei with 32 neutrons, its effect is weak, and in some neighbors it seems absent altogether.

Inside an atomic nucleus, protons and neutrons don't sit still like peas in a pod. Each particle occupies its own orbit — a region of space where it can be found. The larger the orbit, the more 'smeared out' the particle is.