Scattering is a general term for several physical processes in which radiation of some sort changes direction due to an interaction with a particle. Scattering can be classified by the type of radiation (ie, electromagnetic, x-ray, neutron), or by the relative sizes of the wave and the particle (ie, ...
[I edited the question according to Mark's and Grisha's answers.] Consider two point-like particles of equal mass colliding centrally in 2D. The final directions of the momenta of the two particles ...
Why the sky is blue during the day, red during sunrise/set and black during the night?