He was deeply committed to educating the public and political leaders about science and its implications, most notably as a principal founder of the Bulletin of the Atomic Scientists and a long-time member of the organizations Board of Sponsors.
[3] Born in Portland, Oregon, Simpson was an accomplished clarinetist and saxophonist in his early years, receiving an award in high school for his virtuosity.
[1] He received an AB degree from Reed College in 1940, where he became interested in the history of science and technology from the Greeks to the Middle Ages to the most recent discoveries in astronomy and physics.
Volney Wilson, an administrator at the university's Metallurgical Laboratory asked him to help invent instruments for measuring high levels of radioactivity.
[2] This same year Simpson began his tenure as a faculty member at the University of Chicago as a physics instructor, and remained there throughout his career, partaking in research until shortly before his death in August 2000.
[1] Simpson has 15 patents under his name, which include the multiwire proportional counter, a device that improves accuracy and reading speed of radiation, and the neutron monitor.
In 1955, he gave Eugene N. Parker a job as a research associate in the Enrico Fermi Institute of the University of Chicago, and his progress was largely a consequence of Simpson's continued support.
[1][4] At the end of 1957, after the launch of Sputnik by the Soviet Union, Simpson, realizing the necessity for the US to send instruments into space, outlined the scientific situation and his plans for such activity to University Chancellor Lawrence Kimpton.
Kimpton granted Simpson $5,000 to get the project off the ground, and partnered with Peter Meyer to develop small lightweight particle detectors suited for the space environment.
In 1962, Simpson and Professor Peter Meyer established the Laboratory for Astrophysics and Space Research (LASR) which was built within the Enrico Fermi Institute at the University of Chicago.
Simpson's detection in 1974 is what first established that the magnetic fields observed at Mercury were not carried from the Sun by solar wind, but in fact belonged to the planet itself.
In 1970, Simpson, William Dietrich, and John David Anglin discovered that some impulsive sun flares produce energetic particles, among which helium-3 (a light non-radioactive isotope of helium with two protons and one neutron) is at least ten times more abundant than helium-4 (another light non-radioactive isotope of helium with two protons and two neutrons).
This led him to conclude that cosmic rays pass freely between the gaseous disk and the extended magnetic halo portion of the galaxy, where the ambient gas density is on the order of 10−2 atoms/cm3 or less.
[1] John Alexander Simpson is known for inventions such as the "gas flow α-particle proportional counter", which measures plutonium yields in the presence of high intensity fission products, and the neutron monitor.
Simpson is the recipient of the 1986 Gagarin Medal for Space Exploration for his contribution towards the success of the Vega program, which sent satellites to Halley's Comet earlier that year.