Samuel Theodore Cohen (January 25, 1921 – November 28, 2010) was an American physicist who invented the W70 warhead and is therefore generally credited as the father of the neutron bomb. Cohen's parents were Austrian Jews who emigrated from London, England. He was born on January 25, 1921, in Brooklyn and raised in New York City. He studied math and physics at UCLA before joining the Army after Pearl Harbor. In 1944 he worked on the Manhattan Project in the efficiency group and calculated how neutrons behaved in Fat Man, the atomic bomb that was later detonated over Nagasaki, Japan. After the war he studied for his Ph.D. at Berkeley before dropping out to join the RAND Corporation. At RAND Corporation in 1950, his work on the intensity of fallout radiation first became public when his calc