Arthur Compton

Arthur Holly Compton (1892–1962) was an American physicist whose 1923 demonstration that X-rays scatter from electrons with a measurable change in wavelength provided experimental confirmation that electromagnetic radiation behaves as quantized particles. The phenomenon, now called the Compton effect, won him the 1927 Nobel Prize in Physics, shared with Charles Thomson Rees Wilson, and stands as one of the founding experiments of quantum mechanics.

Born in Wooster, Ohio, the son of a Presbyterian minister and dean of the College of Wooster, Compton graduated from his father's college in 1913 and earned his doctorate at Princeton University in 1916. After teaching briefly at the University of Minnesota and working as a research engineer at Westinghouse, he spent the academic year 1919–1920 at the Cavendish Laboratory in Cambridge studying the scattering of gamma rays.

His decisive experiments were carried out at Washington University in St. Louis between 1921 and 1923, where he showed that the wavelength shift in scattered X-rays matched precisely the prediction obtained by treating the radiation as photons colliding with electrons. He moved to the University of Chicago in 1923 and continued research on cosmic rays, leading worldwide expeditions in the early 1930s that established the latitude effect and helped identify cosmic rays as charged particles.

During the Second World War he directed the Manhattan Project's Metallurgical Laboratory at Chicago, where Enrico Fermi achieved the first self-sustaining nuclear chain reaction on 2 December 1942 under the bleachers of Stagg Field. After the war he served as chancellor of Washington University from 1945 to 1953, presiding over the institution's expansion and integration. He published the textbook X-Rays and Electrons and the autobiography Atomic Quest.

The name Arthur derives uncertainly from the Celtic artos, meaning "bear," or possibly from the Roman family name Artorius. Borne by the legendary British king and by generations of English-speaking statesmen and scientists, it carried Compton through a long career of measurement and administration.