Are neutrinos helping to pull the universe together?
They are the ghosts of particle physics, so tiny and elusive that a billion could pass through a bar of lead without hitting anything en route. Traveling at the speed of light, neutrinos carry no charge and apparently no mass. Even after they were detected in 1956, they remained curious, spectral bits of energy. As one of the scientists who discovered them, Frederick Reines, explains, they seemed to have "no frills and no complications."
Last week Reines astonished colleagues with word that neutrinos may not be...