The California Tech Volume CXiX number 4 Pasadena, California
[email protected] oCtober 19, 2015 Alumnus Arthur McDonald wins Nobel Prize in Physics DOUGLAS SMITH and it slowly became apparent that planet, Kajita and his colleagues The conclusion, for which a postdoctoral researcher under Caltech Media Relations as few as one-third of the neutrinos concluded that the extra distance McDonald and Kajita were Barnes. “It is a shame that Charlie the theorists said the sun should had given them a little extra time awarded the Nobel Prize, was that didn’t get to see Art receive this This article was originally be emitting were actually being to change their identities. neutrinos must have a nonzero tremendous honor.” published online at caltech.edu. observed. Various theories were McDonald’s SNO, built 2,100 mass. Quantum mechanics A native of Sydney, Canada, proposed to explain the deficit, meters deep in a nickel mine, began treats particles as waves, and McDonald received his bachelor Arthur B. McDonald (Ph.D. ’70), including the possibility that the taking data in 1999. It has two the potentially differing masses of science and master’s degrees, director of the Sudbury Neutrino detectable electron neutrinos were counting systems. One is exclusively associated with muons and taus both in physics, from Dalhousie Observatory (SNO) in Ontario, somehow transmuting into their sensitive to electron neutrinos, gives them different wavelengths. University in Halifax, Nova Scotia, Canada, and Takaaki Kajita, at undetectable kin en The probability in 1964 and 1965, respectively. the University of Tokyo, Kashiwa, route to Earth. waves of the three After receiving his doctorate, Japan, have shared the 2015 Nobel Solving the particle types are he worked for the Chalk River Prize in Physics for the discovery mystery of the aligned when the Laboratories in Ontario until 1982, that neutrinos can change their missing neutrinos particle is formed, when he became a professor of identities as they travel through would require but as they propagate physics at Princeton University.