Carl David Anderson, Physicist was born Sept. 3, 1905, New York, U.S. He studied physics and engineering at Caltech (B.S., 1927); and received his Ph.D. in 1930. Having studied X-ray photoelectrons since 1927, he began research in 1930 on gamma rays and cosmic rays. He is best known for his discovery of the positron in 1932, an achievement for which he received the 1936 Nobel Prize in Physics, and of the muon in 1936. Anderson spent all of his academic and research career at Caltech. He was also elected a Fellow of the American Academy of Arts and Sciences in 1950.