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John A. Simpson Jr.

PhysicistChicago, IL

Manhattan Project VeteranScientist
John A Simpson Jr.

John A. Simpson Jr. (1916-2000) was a distinguished American nuclear physicist and astrophysicist.

Simpson was born on November 3, 1916 in Portland, Oregon. He graduated from Reed College, and received his masters and doctoral degrees from New York University. In 1943, Simpson joined the Manhattan Project at the University of Chicago Met Lab and worked as a physicist in the instrumentation division, developing radiation detectors.

Deeply concerned about the dangers of nuclear weapons, Simpson signed the Szilard Petition. He was a co-founder and founding chairman of the Bulletin of the Atomic Scientists. In October 1945, he and Eugene Rabinowitch wrote an influential article for Life magazine declaring that scientists had a moral responsibility to warn against further use of nuclear weapons. Simpson also advised Senator Brien McMahon, chairman of the Joint Committee on Atomic Energy and sponsor of the Atomic Energy Act, which ensured civilian control of nuclear energy.

After the Manhattan Project, Simpson was a longtime professor of physics at the University of Chicago. He made major contributions to astrophysics, including inventing a neutron monitor to detect the intensity of cosmic rays. The equipment he developed was essential to dozens of space missions, including the Pioneer 10 mission to Jupiter, and provided scientists with valuable information about the solar system.

In 2000, Simpson received the William Bowie Medal, the American Geophysical Union’s highest honor. He died in Chicago on August 31, 2000.

 

John A. Simpson Jr.'s Timeline
1916 Nov 3rd Born in Portland, Oregon.
1940 Received a B.A. from Reed College.
1942 Received an M.S. from New York University.
1943 Received a Ph.D. from New York University.
19431946 Worked on the Manhattan Project in the instrumentation division at the University of Chicago Met Lab.
1945 Signed the Szilard petition.
19451946 Co-founded and served as founding chairman of the Bulletin of the Atomic Scientists.
19451946 Advised Senator Brien McMahon, chairman of the Joint Committee on Atomic Energy and sponsor of the Atomic Energy Act, which ensured civilian control of nuclear energy.
1948 Invented a neutron monitor to detect the intensity of cosmic rays.
1959 Elected to the National Academy of Sciences.
1972 Built equipment for Pioneer 10, the first spacecraft to travel through the asteroid belt and make direct observations of Jupiter.
19731978 Directed the Enrico Fermi Institute of Nuclear Studies.
1987 Retired from the University of Chicago as Arthur Holly Compton Distinguished Service Professor, Emeritus.
2000 Awarded the William Bowie Medal.
2000 Aug 31st Died in Chicago, Illinois.

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