I will continue with a note that uses the Debye theory to calculate the velocity magnitude v so that photon mass can be calculated. The theory of shifts caused by the Beer Lambert law was first developed some year ago by Assis and co workers and cited in UFT49. The latter paper should be read as background material. It also gives the link between the power absorption coefficient and the Hubble constant. In UFT300 and UFT304 it is greatly developed in the context of the important Evans / Morris effects.