For 10 points, name this physical process in which radiation deviates from a straight path.
The differential cross-section of particles undergoing one type of this process at the lowest order is given by the Klein-Nishina formula. This process happens to particles in the Cosmic Microwave Background Radiation that move through hot gas, resulting in the (*) Sunyaev-Zeldovich (SOON-yuh-eev ZELL-doe-vich) effect. The Compton form of this process is inelastic, while the Raman form of it is elastic. The Rayleigh form of it partially explains why the sky is blue. For 10 points, name this physical process in which radiation deviates from a straight path.
The differential cross-section of particles undergoing one type of this process at the lowest order is given by the Klein-Nishina formula.
{scattering}