The phenomenological electromagnetic force density

Abstract

The "current loop" model for a magnetic dipole is thoroughly examined in connection with the electromagnetic force density in material media. An updated and theoretically consistent expression for that force density is presented which differs from the Livens' and Page–Adams' proposals in minor details. The notation in our updated formula gives precise information about the volume elements within the material medium which are the seats where the different force density terms are localized. The corresponding tensor theory is also developed and, using the concept of localized Poynting vector, a new interpretation of the "Lorentz diffraction" phenomenology is suggested which would seem to explain the observed small deviations from the mean deflection.