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
Something More Than Free "Something More Than Free" is as real as it gets." In a mixed review, "Pitchfork"s Stephen Deusner described "Something More Than Free" as " an album that contains too few surprises," writing that "the music does little to distinguish these characters or enliven the lyrics." In an otherwise positive review, Jeremy Winograd of Slant Magazine wrote that "Something More Than Free" "retains "Southeastern"'s intimate acoustic-based feel and heavyhearted lyrical matter, but it's even more smooth-edged and lacks the emotional gut-punches of its predecessor." The album debuted on the "Billboard" 200 at No. 6, and on the Top Country Albums as