Philip Morrison


En 1945, Philip Morrison fait partie des physiciens qui travaillent à l’élaboration de la première bombe nucléaire américaine. Il transporte le dispositif de détonation de l’engin nucléaire sur le siège arrière de sa Dodge. Après la guerre, il devient l’un des plus farouches opposants au développement des armes atomiques. En 1958, il publie une série d’articles qui jettent les bases de ce qui deviendra l’astronomie gamma, et qui permet d’observer les plus violents phénomènes du cosmos grâce aux rayons gamma qui viennent frapper la terre dans de grandes piscines d’eau purifiées.

Philip Morrison (November 7, 1915 – April 22, 2005) was a professor of physics at the Massachusetts Institute of Technology (MIT).

In 1944 he moved to the Manhattan Project’s Los Alamos Laboratory in New Mexico, where he worked with George Kistiakowsky on the development of explosive lenses required to detonate the implosion-type nuclear weapon. Morrison transported the core of the Trinity test device to the test site in the back seat of a Dodge sedan. As leader of Project Alberta’s pit crew he helped load the atomic bombs on board the aircraft that participated in the atomic bombing of Hiroshima and Nagasaki. After the war ended, he traveled to Hiroshima as part of the Manhattan Project’s mission to assess the damage.

After the war he became a champion of nuclear nonproliferation. He wrote for the Bulletin of the Atomic Scientists, and helped found the Federation of American Scientists and the Institute for Defense and Disarmament Studies. He was one of the few ex-communists to remain employed and academically active throughout the 1950s, but his research turned away from nuclear physics towards astrophysics. He published papers on cosmic rays, and a 1958 paper of his is considered to mark the birth of gamma ray astronomy. He was also known for writing popular science books and articles, and appearing in television programs.

ollowing his political stances, Morrison’s attention began drifting towards the stars. In 1954, he published a paper with Bruno Rossi and Stanislaw Olbert in which they explored Enrico Fermi’s theory of how cosmic rays travel through the galaxy. Morrison followed this up with a review of theories of the origins of cosmic rays in 1957. A 1958 paper in Nuovo Cimento is considered to mark the birth of gamma ray astronomy.