Excitation and Nature of X-Rays; X-Ray Spectra

Abstract

By the late 1800’s, many eminent physicists had come to believe that the nature of the physical world was substantially understood and that there remained only to acquire detail and refine data. This complacency was decisively shattered by an unprecedented series of truly epochal discoveries, all within a period of about two decades: radio (Hertz, 1887); an entire, wholly unsuspected group of inert chemical elements (Ramsay, Rayleigh, and Travers, 1895-98); x-rays (Roentgen, 1895); radioactivity (Becquerel, 1896; the Curies, 1898); the electron (Thomson, 1897); quantum theory (Planck, 1900; Einstein, 1901); relativity theory (Einstein, 1905); and cosmic rays (Hess, 1910).