Hofstadter, Robert (1915-1990), an American physicist, was awarded the Nobel Prize in physics in 1961 for his studies of nucleons, the particles that make up the nuclei of atoms. The two types of nucleons are neutrons and protons. Hofstadter’s work revealed the structure of protons and neutrons, and in particular, that both particles have a positively charged core. The charge of this core is either strengthened (in the proton) or neutralized (in the neutron) by clouds of positively charged particles called pi mesons surrounding the core. See Atom (The parts of the atom) ; Meson . Hofstadter shared the Nobel Prize with Rudolf Ludwig Mossbauer of Germany. See Mossbauer, Rudolf Ludwig.
After World War II (1939-1945), Hofstadter did research into scintillation counters (devices that detect and count radioactive particles).
In the 1950’s, he bombarded atomic nuclei with beams of high-energy electrons. By studying how electrons scattered from the nuclei, he could explore the size, charge, and magnetic force of nuclei and their component nucleons.
Robert Hofstadter was born in New York City. He studied at Princeton University. He taught at the University of Pennsylvania, the City College of New York, and at Princeton and Stanford universities.
