Resonance Radiation and the Quantum Theory

Abstract

IN the Philosophical Magazine for September, 1916, Dr. Silberstein has made an attempt to explain the resonance radiation of iodine vapour on the basis of classical dynamics by assuming that the resonator is non-Hookean—i.e. that its restitutive elastic force is not simply proportional to the displacement. On this theory, the principal lines in the resonance series should appear at constant frequency-intervals, and to support this view Dr. Silberstein has given a tabular statement of the frequencies and their differences, based upon the work of Prof. R. W. Wood. A critical examination of the figures shows, however, that the frequency-intervals are by no means constant, but have a decided tendency to decrease on the long wave-length side. This has, indeed, been remarked upon by Prof. Wood himself (Phil. Mag., October, 1912). I find on calculation that it is not the frequencies themselves, but their square-roots, that show constant decrements in the series. The following table, prepared from Prof. Wood's data (loc. cit., p. 684) for the mercury green line excitation, demonstrates this clearly:—