Materials seem to have different refractive indices for some sort of complicated quantum reason that only relies on the inhomogenity because of materials being

Materials seem to have different refractive indices for some sort of complicated quantum reason that only relies on the inhomogenity because of materials being made up of atoms containing electrons, not an sort of macroscopic inhomogenity. https://www.physicsforums.com/threads/how-does-refraction-work-on-the-quantum-level.499240/ https://www.physicsforums.com/threads/how-does-refraction-wo... is the thread I'm basing this on