LOCAL : Discoverer of Positron Dies, 85

Carl David Anderson, winner of the 1936 Nobel Prize in physics for his discovery of the positron, died today at his home in San Marino after a short illness. He was 85.

Anderson, a professor emeritus at California Institute of Technology, discovered the positron--a positively charged electron--while he was trying to measure the penetrating power of cosmic rays. Until then, scientists had identified only two elementary particles of matter: the electron, with its negative charge, and the positively charged proton.

Anderson’s research determined that there are positively charged electrons.

The particle eventually was named the positron and its existence was the first confirmation of the concept of antimatter developed by the British physicist Paul Durac.

Anderson shared the 1936 prize with Viktor F. Hess, the discover of cosmic rays.