S. Takeshita

In a solid crystal resembling a layered cake of lanthanum, oxygen, and hydrogen atoms, electricity is carried not by electrons but by hydrogen ions themselves. Usually, an ion in a crystal sits in its own cell like a pea in a pod, occasionally hopping to a neighboring empty cell. But in this material, things are different.

Neutrinos are nearly elusive particles that pass through Earth without noticing it. But sometimes one slams into an atomic nucleus in water, and a whole shower of particles is born: muons, protons, pions. Catching that moment is like photographing a bullet hitting an apple from a kilometer away.