This is the Compton Effect. And no, it doesn't have anything to do with the hometown of the NWA. No, the compton effect is the term given to the increase in wavelength that occurs when photons interact with electrons in a material. The high energy that photons possess can be transferred to electrons and gives them enough energy to be launched out of the atom, and for a photon containing the remaining energy to be emitted in a different direction than the original. This way the overall momentum is conserved. If the photon still contains enough energy, this process can be repeated.

The wavelength of the photons increases because of the decrease in their energy. Because of their change in direction, there can be a slight scattering, usually referred to as "Compton Scattering." In a material where some electrons are free, this effect will occur at all photon energies and hence all wavelengths.

The importance of this effect is that it provides evidence to the now proven theory that light is not only a wave phenomenon, but also has particle properties as well. The Compton Effect has occassionally been proposed as an explanation for the idea of the "Redshift" (by opposers of the Big Bang Theory. This isn't normally accepted, however, because the influence of the effect would be noticeable in the spectral lines of other objects, and this has not been observed.