Anderson, Carl David 1905-91
US physicist and Nobel Prize winner

Born in New York City, he studied at the California Institute of Technology (Caltech) under Robert Millikan, and in 1932 discovered the positron, the positively charged electron-type particle, thus confirming the existence of antimatter predicted by Paul Dirac. He did notable work on gamma and cosmic rays, and was awarded the 1936 Nobel Prize for physics (jointly with Victor Hess). Later he confirmed the existence of intermediate-mass particles known as mesons or muons. He spent his entire career at Caltech and was named professor emeritus in 1976.