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Enrico Fermi believed that good looks and height were inversely proportional to intelligence, but he was willing to allow an exception in the case of the tall and handsome Arthur Compton. Compton demonstrated the magnitude of his formidable intelligence very early in his career. In 1919, shortly after receiving his doctorate in physics from Princeton, Compton spent a year in Cambridge working under Ernest Rutherford investigating the properties of scattered gamma rays. In the early 1920's, at Washington University in St. Louis, he continued this line of research using X rays instead of gamma rays. He discovered that the scattering of the X rays by graphite lowered their energy. Compton hypothesized that the X rays must be behaving like particles (i.e., photons) that transferred their energy to the electrons of the graphite in a "collision". This would not happen if X rays behaved exclusively as waves. For example, the wavelength (i.e., pitch) of sound does not change as it is reflected off a surface. This provided experimental proof that electromagnetic radiation could exhibit the characteristics of particles as well as waves. In acknowledgement of the importance of this work, Compton was awarded the 1927 Nobel Prize in physics. His research then shifted to investigations of cosmic rays. Measurements at thousands of locations around the world showed that the intensity of cosmic rays was affected by the earth's magnetic field. This provided conclusive evidence that cosmic rays must consist of charged particles. At the outbreak of WW II, Compton's reputation was such that he was asked to direct the Metallurgical Laboratory. The "Met Lab", as it was called, was the organization at the University of Chicago that helped guide the nation's scientific efforts devoted to the development of the atomic bomb.

Index Of Figures In Radiation History