Note 51 — Chapter XIV · RELATIVISTIC MECHANICS

A further verification was afforded when the mechanism of Bohr’s atom was studied by Sommerfeld. In Bohr’s atom the electrons revolve round the central nucleus in certain stable orbits. Sommerfeld, by taking into consideration the variations in mass of the electrons due to their motions as necessitated by Einstein’s theory, proved that in place of the sharp spectral lines which had always been observed it was legitimate to expect that more accurate observation would prove these sharp lines to be bundles of very fine ones closely huddled together. These anticipations were confirmed by experiment both qualitatively and quantitatively.