A golden age for the neutrino is dawning.

A few decades ago, these shy phantoms that flit nearly unfelt through the interstices of the universe seemed mere leftovers in the world of physics.

They outnumber all other particles of matter, whizzing away everywhere — many of them arising in droves from nuclear reactors and nucleosynthesis in stars. Their characteristics made them, to be sure, vitally important building blocks in the 1970s and ’80s for theorists who put together the standard model of physics, describing how fundamental forces and particles fit together. Yet, for decades, neutrinos seemed nearly incapable of doing a lick of work. They were like clowns pouring from a circus car, entertainment for theorists but without important jobs in keeping the cosmos running smoothly. (more)