1905 – Born on September 3rd in New York, New York. American physicist who, with Victor Francis Hess of Austria, won the Nobel Prize for Physics for his discovery of the positron, or positive electron, the first known particle of antimatter.
1930 – Anderson received his Ph.D. from the California Institute of Technology, Pasadena, where he worked with physicist Robert Andrews Millikan.
– Having studied X-ray photoelectrons (electrons ejected from atoms by interaction with high-energy photons), he began research on gamma rays and cosmic rays.
1932 – He announced that they were caused by positrons, positively charged particles with the same mass as electrons. The claim was controversial until verified the next year by British physicist Patrick M.S. Blackett and Italian Giuseppe Occhialini.
1936 – Anderson discovered the mu-meson, or muon, a subatomic particle 207 times heavier than the electron. At first he thought he had found the meson, postulated by the Japanese physicist Jukawa Hideki, that binds protons and neutrons together in the nucleus of the atom, but the muon was found to interact weakly with these particles.
1976 – Anderson spent his entire career at Caltech, joining the faculty and serving as professor.
– During World War II he conducted research on rockets.
1991 – Died on January 11th in San Marino, California.