Carl David Anderson

Carl David Anderson (3 September 1905 – 11 January 1991) was a U.S. experimental physicist. He was born in New York City, the son of Swedish immigrants. He studied physics and engineering at Caltech (B.S., 1927; Ph.D., 1930). Under the supervision of Robert A. Millikan, he began investigations into cosmic rays during the course of which he encountered unexpected particle tracks in his cloud chamber photographs that he correctly interpreted as having been created by a particle with the same mass as the electron, but with opposite electrical charge. This discovery, announced in 1932 and later confirmed by others, validated Paul Dirac's theoretical prediction of the existence of the positron. Anderson obtained the first direct proof that positrons existed by shooting gamma rays produced by thorium carbide (ThC) into other materials, resulting in creation of positron-electron pairs. For this work, Anderson shared the Nobel Prize in physics for 1936 with Victor Hess.

External links

• Carl David Anderson