Unretarded London-van der Waals Forces Derived from Classical Electrodynamics with Classical Electromagnetic Zero-Point Radiation

The unretarded London-van der Waals force between a neutral polarizable particle and a conducting wall, and between two neutral polarizable particles are derived from classical electromagnetism under the assumption that the universe contains fluctuating classical electromagnetic radiation with a Lorentz-invariant spectrum, (classical electromagnetic zero-point radiation). The classical derivations correspond in detail to the familiar charge-fluctuation arguments which have been advanced previously as qualitative semiclassical descriptions of quantum calculations of these forces.