Atomic, molecular, and optical physics the origin of the index of refraction treated an electron in an atomic system classically according to the model of Paul Drude and Hendrik Lorentz. The theory was developed to attempt to provide an origin for the wavelength-dependent refractive index "n" of a material. In this model, incident electromagnetic waves forced an electron bound to an atom to oscillate. The amplitude of the oscillation would then have a relationship to the frequency of the incident electromagnetic wave and the resonant frequencies of the oscillator. The superposition of these emitted waves from many oscillators would then lead to a wave which
Tendency of the rate of profit to fall and which received some glowing reviews, Heinrich – who is the chief editor of the leftist flagship magazine PROKLA in Germany – argued that the rate of profit can both rise and fall. Therefore, "A long-lasting tendency for the rate of profit to fall cannot be substantiated at the general level of argumentation by Marx in "Capital"." By the end of 2013, leftwing economist Michael Yates stated: "What exasperates me more and more is the certainty with which so many people pontificate [about the tendency of the rate of profit to fall]". He argued the evidence for the tendency was