Neutrino astronomy: Seeing without light

Observation of neutrinos registered by the IceCube experiment

As you read this, 10m neutrinos are passing through your eyes every second, at almost the speed of light, unseen. These will o’ the wisps are the most enigmatic particles in the universe. They are like electrons except that they have no electrical charge and almost no mass. They are impervious to electric and magnetic forces, and interact with matter through the “weak” force—the feeblest of the natural forces other than gravity. So their faint affinity for matter makes neutrinos very hard…