A Japanese scientist has won this year's Nobel Prize in Physics. Takaaki Kajita proved that neutrinos have mass. The neutrino is an elementary particle consisting of matter. Kajita observed neutrinos at a facility deep underground. He was part of a team that detected that some of the particles change to different types of neutrino. That proved neutrinos have mass. The discoveries were revealed at an international conference in 1998. His work surprised researchers all around the world because it disproved the established theory that neutrinos do not have mass. Kajita is the 24th Nobel Prize winner born in Japan. And...