Neutrinos change from one type into another as they travel. Across Japan from east coast Tokai to the west coast Super-Kamiokande in 2011 muon neutrino to electron neutrino oscillations are detected. Experiments continue to find out more about how neutrinos and other elementary particles change in from one type into another. The transitions between different states may indicate that neutrinos masses come from energies of the universe deep as quantal interchanges.
