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 Causality, cause-and-effect by demonstrating what outcome oc ...

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 caus ...

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

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

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

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...

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

Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach an ...

. Some of his principal studies included: *

Scattering Scattering is a term used in physics to describe 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 ...

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 partic ...

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

spectroscopy Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wa ...

; *X-ray polarization; *

Compton scattering Compton scattering, discovered by Arthur Holly Compton, is the scattering of a high frequency photon after an interaction with a charged particle, usually an electron. If it results in a decrease in energy (increase in wavelength) of the photon ...

; and *

Radiative Auger effect 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 the transition energy is shared b ...

. 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