Nobel Prize in Physics 2015 for the discovery of neutrino oscillations

The Nobel Prize in Physics 2015 recognises Takaaki Kajita in Japan and Arthur B. McDonald in Canada, for their key contributions to the experiments which demonstrated that neutrinos change identities. This metamorphosis requires that neutrinos have mass. The discovery has changed our understanding of the innermost workings of matter and can prove crucial to our view of the universe.