Through the Looking-Glass, and What Maxwell Found There
In his essay on “Mechanical Explanation at the End of the Nineteenth Century,” Martin Klein remarked on “the complexity and variety of the ideas that were current then”: this was “a time of probing and testing.”1 These judgements are aptly descriptive of the physics of James Clerk Maxwell, and especially of his most famous innovation, the electromagnetic theory of light. His statement in 1862, that “light consists in the transverse undulations of the same medium which is the cause of electric and magnetic phenomena,”2 implied the unification of optics and electromagnetism in terms of a mechanical theory of the ether that had both optical and electromagnetic correlates.3 When he wrote his seminal Treatise on Electricity and Magnetism (1873) it might have been anticipated that Maxwell would broaden the scope of his electromagnetic theory of light to encompass an electromagnetic theory of the reflection and refraction of light. But he did not do so; and though he gave a detailed treatment of the Faraday magneto-optic rotation (where he appealed to the rotation of molecular vortices in the ether), the range of his optical theory remained essentially similar in its physical content to that first advanced in 1862 and subsequently amplified in a major paper published in 1865.
KeywordsRoyal Society Ether Theory Electromagnetic Theory Faraday Effect Optical Theory
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- 3.See, especially, Daniel M. Siegel, Innovation in Maxwell’s Electromagnetic Theory. Molecular Vortices. Displacement Current, and Light (Cambridge: Cambridge University Press, 1991), pp. 120–143.Google Scholar
- 32.G.G. Stokes, “On Fresnel’s Theory of the Aberration of Light,” Philosophical Magazine ser. 3, 28 (1846): 76–81.Google Scholar
- 37.Jules Jamin, “Note sur la théorie de la réflection et de la réfraction,” Annales de Chimie et de Physique ser. 3, 59 (1860): 413–426.Google Scholar
- 39.A.J. Fresnel, “Mémoire sur la loi des modifications que la réflexion imprime à la lumière polarisée,” Mémoires de l’ Académie Royale des Sciences 11 (1832): 393–433.Google Scholar
- 40.James MacCullagh, “On the Laws of Crystalline Reflexion and Refraction,” Transactions of the Royal Irish Academy 18 (1837): 31–74; and Franz Neumann, “Theoretische Untersuchung der Gesetze, nach welchen das Licht an der Grenze zweier vollkommen durchsichtigen Medien reflectirt und gebrochen wird,” Mathematische Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin aus dem Jahre 1835 (Berlin, 1837), pp. 1-160.Google Scholar
- 56.Martin J. Klein, “Maxwell, His Demon, and the Second Law of Thermodynamics,” American Scientist 58 (1970): 84–97, esp. 94-95.Google Scholar