The calculation of van der Waals dispersion forces between macroscopic bodies

This paper aims at a simple treatment of van der Waals dispersion forces by applying classical electrostatics of two basic quantum-mechanical equations. Expressions are derived for the forces between macroscopic bodies, and the effects of adsorbed surface layers is considered both quantitatively and qualitatively. Approximate expressions are given for non-retarded dispersion forces in terms of the refractive indices and absorption frequencies of the materials. The results should prove particularly useful in calculating the van der Waals forces in colloidal and biological systems.