Arthur Compton studied at the University of Wooster in Ohio, and was later professor of physics at Washington University in St. Louis, Missouri. He earned the Noble Prize in 1927 for discovering the "Compton Effect" which dictates the amount of change in an x-ray beam when it passes through matter.
Compton was intensively active in the Presbyterian Church. Explaining his work in physics, he said, "a supreme intelligence brought the universe into being and created man. It is incontrovertible that where there is a plan there is an intelligence - and orderly unfolding of the universe testifies to the truth of the most majestic statement ever uttered." He went on: "beyond the nature that science teaches is the Spirit of God that gives order and meaning and purpose to human life."
"Compton scattering" (or "the Compton effect") is the decrease in energy (increase in wavelength) of an X-ray or gamma ray photon, when it interacts with matter. Inverse Compton scattering also exists, where the photon gains energy (decreasing in wavelength) upon interaction with matter. The amount the wavelength increases by is called the Compton shift. Although nuclear compton scattering exists, Compton scattering usually refers to the interaction involving only the electrons of an atom. The Compton effect was observed by Compton in 1923; he earned the 1927 Nobel Prize in Physics for the discovery.
Compton scattering is of prime importance to radiobiology, as it happens to be the most probable interaction of high energy X rays with atomic nuclei in living beings and is applied in radiation therapy. In material physics, Compton scattering can be used to probe the wave function of the electrons in matter in the momentum representation. Compton Scatter is an important effect in Gamma spectroscopy which gives rise to the Compton edge, as it is possible for the gamma rays to scatter out of the detectors used. Compton suppression is used to detect stray scatter gamma rays to counteract this effect.
Inverse Compton scattering is important in astrophysics. In X-ray astronomy, the accretion disk surrounding a black hole is believed to produce a thermal spectrum. The lower energy photons produced from this spectrum are scattered to higher energies by relativistic electrons in the surrounding corona. This is believed to cause the power law component in the X-ray spectra (0.2-10 keV) of accreting black holes. The effect is also observed when photons from the Cosmic microwave background move through the hot gas surrounding a galaxy cluster. The CMB photons are scattered to higher energies by the electrons in this gas, resulting in the Sunyaev-Zel'dovich effect.
