Electromagnetic Standing Waves and Ball Lightning

Abstract

BY now it is well known^1–3 that charged particles moving in harmonically oscillating vacuum electromagnetic fields can be subject to time-average forces which establish a virtual potential minimum for them. The matter takes on a different aspect when the number of particles is so large as to form a highly conducting plasma, as in Kapitza's theory of ball lightning⁴. Then, quite aside from the details of the particle motions, we know that the radiation pressure of the inflowing electromagnetic radiation is exerted on the energy-dissipating plasma. Thus, if the maintenance of a local ball of fire requires about 20 kW. (2 × 10¹¹ dyne cm. sec.⁻¹), the total force, irrespective of direction, associated with this energy conversion will be 6.7 dynes. To the extent that, besides the 20 kW. absorbed, there may be energy reflected, this number will be greater. A reflected 20 kW. will contribute 13.3 dynes. This is far too little to hold a fire-ball at several thousands of degrees temperature and, say, 10 cm. in diameter from rising under the unidirectional buoyant force of about 600 dynes.