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 Something More Than Free is the fifth studio album by Jason Isbell. It was produced by Dave Cobb, who also produced Isbell's last record, "Southeastern". The album received the Grammy Award for Best Americana Album at the 58th Annual Grammy Awards. "Something More Than Free" received mostly positive reviews. On Metacritic, the album has a score of 87 out of 100 based on 25 reviews, indicating "universal acclaim." "The A.V. Club"s Eric Swedlund praised the album, writing "though "Something More Than Free" may not repeat Isbell’s album-of-the-year accolades, it continues the magic of that breakthrough LP."