Carl David Anderson
Born: 3 September 1905, New York, NY, USA
Died: 11 January 1991, San Marino, CF, USA
Affiliation at the time of the award: California Institute of Technology (Caltech), Pasadena, CA, USA
Prize motivation: "for his discovery of the positron"
Field: particle physics
Prize share: 1/2
In developing quantum mechanics, Paul Dirac proposed that all matter has a kind of mirror image - antimatter. A particle and its antiparticle, if charged, should have opposite charge. In studying tracks of cosmic ray particles in a cloud chamber, Carl Anderson discovered in 1932 a particle of positive charge and with a mass equal to that of the electron. Anderson's particle was the first established antiparticle and was named positron.