# Clinton Davisson

Clinton Joseph Davisson (October 22, 1881 – February 1, 1958) was an American physicist who shared the 1937 Nobel Prize in Physics with George Paget Thomson "for their experimental discovery of the diffraction of electrons by crystals".

## Early life and education

Davisson was born in Bloomington, Illinois on October 22, 1881. He graduated from Bloomington High School in 1902, and entered the University of Chicago on scholarship. Upon the recommendation of Robert A. Millikan, in 1905 Davisson was hired by Princeton University as Instructor of Physics. He completed the requirements for his B.S. degree from Chicago in 1908, mainly by working in the summers. While teaching at Princeton, he did doctoral thesis research with Owen Richardson. He received his Ph.D. in physics from Princeton in 1911; in the same year he married Richardson's sister, Charlotte.

## Scientific career

After earning his Ph.D., Davisson was appointed as an assistant professor at the Carnegie Institute of Technology. In 1917, he took a leave from the Carnegie Institute to do war-related research with the engineering department of the Western Electric Company (later Bell Telephone Laboratories). At the end of the war, Davisson accepted a permanent position at Western Electric after receiving assurances of his freedom there to do basic research. He had found that his teaching responsibilities at the Carnegie Institute largely precluded him from doing research. Davisson remained at Western Electric (and Bell Telephone) until his formal retirement in 1946. He then accepted a research professor appointment at the University of Virginia that continued until his second retirement in 1954. Davisson was elected to the American Philosophical Society, the American Academy of Arts and Sciences, and the United States National Academy of Sciences in 1929.

### Electron diffraction and the Davisson–Germer experiment

Diffraction is a characteristic effect when a wave is incident upon an aperture or a grating, and is closely associated with the meaning of wave motion itself. In the 19th century, diffraction was well established for light and for ripples on the surfaces of fluids. In 1927, while working for Bell Labs, Davisson and Lester Germer performed an experiment showing that electrons were diffracted at the surface of a crystal of nickel. This celebrated Davisson–Germer experiment confirmed the de Broglie hypothesis that particles of matter have a wave-like nature, which is a central tenet of quantum mechanics. In particular, their observation of diffraction allowed the first measurement of a wavelength for electrons. The measured wavelength $\lambda$ agreed well with de Broglie's equation $\lambda =h/p$, where $h$ is the Planck constant and $p$ is the electron's momentum.

## Personal life

While doing his graduate work at Princeton, Davisson met his wife and life companion Charlotte Sara Richardson, who was visiting her brother, Professor Richardson. Richardson is the sister-in-law of Oswald Veblen, a prominent mathematician. Clinton and Charlotte Davisson (d.1984) had four children, Owen Davisson, James Davisson, the American physicist Richard Davisson, and Elizabeth Davisson.

## Death and legacy

Davisson died on February 1, 1958 in Charlottesville, Virginia, at the age of 76.
An impact crater on the far side of the Moon was named after Davisson in 1970 by the IAU.