Perley Ason Ross (6 April 1883 – 13 March 1939) was a U.S.

experiment An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs whe ...

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

who worked, carefully and without seeking publicity, at some essential problems in the behaviour of

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

s. Born in Panacea, Missouri he was awarded his PhD from

Stanford University Leland Stanford Junior University, commonly referred to as Stanford University, is a Private university, private research university in Stanford, California, United States. It was founded in 1885 by railroad magnate Leland Stanford (the eighth ...

in 1911, becoming a full professor there in 1927, after a year at

Cornell University Cornell University is a Private university, private Ivy League research university based in Ithaca, New York, United States. The university was co-founded by American philanthropist Ezra Cornell and historian and educator Andrew Dickson W ...

. Some of his principal studies included: *

Scattering In physics, scattering is a wide range of physical processes where moving particles or radiation of some form, such as light or sound, are forced to deviate from a straight trajectory by localized non-uniformities (including particles and radiat ...

of X-rays by

matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic pa ...

; *Development of the Ross differential filter for X-ray

spectroscopy Spectroscopy is the field of study that measures and interprets electromagnetic spectra. In narrower contexts, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Spectro ...

; *X-ray

polarization Polarization or polarisation may refer to: Mathematics *Polarization of an Abelian variety, in the mathematics of complex manifolds *Polarization of an algebraic form, a technique for expressing a homogeneous polynomial in a simpler fashion by ...

; *

Compton scattering Compton scattering (or the Compton effect) is the quantum theory of high frequency photons scattering following an interaction with a charged particle, usually an electron. Specifically, when the photon hits electrons, it releases loosely bound e ...

; and *

Radiative Auger effect In optics and spectroscopy, the radiative Auger effect is a decay channel of an inner-shell atomic vacancy state, in which an X-ray photon is emitted accompanying simultaneous promotion of an electron into either a bound or a continuum state. Thus t ...

. His daughter, Betsy, married fellow Stanford physicist William Webster Hansen.Süsskind, C. (1981) "Hansen, William Webster" in

References

1883 births 1938 deaths Stanford University alumni Stanford University Department of Physics faculty Fellows of the American Physical Society {{US-physicist-stub