Samuel King Allison

From Wikipedia, the free encyclopedia

Samuel King Allison

Samuel King Allison (November 13, 1900 – September 15, 1965) was an American physicist, most notable for his role in the Manhattan Project — where among other things he read the countdown for the detonation of the "Trinity" test — and his postwar work in the "scientists' movement".

[edit] Biography

Samuel K. Allison was born in Chicago, Illinois, and attended the University of Chicago for his undergraduate degree as well as for his PhD (in chemistry, though his thesis was related to experimental physics). From 1923 until 1925 he was a research fellow at Harvard University and from 1925 until 1926 he was a research fellow at the Carnegie Institution From 1926 until 1928 he taught physics at University of California, Berkeley, after which he returned to the University of Chicago, where he studied the Compton effect and the dynamical theory of x-ray diffraction. He developed a high resolution x-ray spectrometer with a graduate student, John H. Williams. In the late 1930s, he studied with John Cockcroft at the Cavendish Laboratory, learning about linear accelerators, and after returning to Chicago he built one. He authored a textbook on x-rays with Arthur Compton which became widely used.

During World War II, Allison was a consultant to the National Defense Research Committee and the Uranium (S-1) Committee, the early investigations into the feasibility of an atomic bomb which would later become the Manhattan Project. He worked at the Chicago Metallurgical Laboratory and was its director from 1943 until 1944. He then went to work at the secret Los Alamos laboratory in New Mexico. Notably, he was the one who read the countdown over the loudspeakers for the "Trinity" test in 1945.

Allison's ID badge photo from Los Alamos.

After the war, Allison became director of the Enrico Fermi Institute of Nuclear Studies from 1946 until 1957, and again from 1963 until 1965. He was active in the "scientist's movement" for the control of atomic weapons, and was a founder of the Bulletin of the Atomic Scientists. He was a strong opponent of secrecy in science, and was once quoted as saying:

We are determined to return to free research as before the war. If secrecy is imposed on scientific research in physics, we will find all first-rate scientists working on subjects as innocuous as the colors of butterfly wings.

Allison died in 1965 while attending the Plasma Physics and Controlled Nuclear Fusion Research Conference in Culham, England of complications following an aortic aneurism. His papers are kept at the American Institute of Physics.