Abstract

We have now celebrated the centenary of J. J. Thomson’s famous paper (1897) on the electron and have examined one hundred years of the history of our first fundamental particle. What should philosophers of science learn from this history? To some, the fundamental moral is already suggested by the rapid pace of this history. Thomson’s concern in 1897 was to demonstrate that cathode rays are electrified particles and not aetherial vibrations, the latter being the “almost unanimous opinion of German physicists” (p. 293) But were these German physicists so easily vanquished? De Broglie proposed in 1923 that electrons are a wave phenomenon after all and his proposal was soon multiply vindicated, even by the detection of the diffraction of the electron waves. Should we not learn from such a reversal? Should we not dispense with the simple-minded idea that Thomson discovered our first fundamental particle and admit that the very notion of discovery might well be ill-suited to science?