>In 1818 Fresnel entered a competition sponsored by the French Academy. His paper on the theory of diffraction ultimately won first prize and the title Memoire Courronne, but not before it had provided the basis for a rather interesting story. The judging committee consisted of Pierre Laplace, Jean B. Biot, Simeon D. Poisson, Dominique F. Arago and Joseph L Gay-Lussac, a formidable group indeed. Poisson, who was an ardent protagonist against the wave description of light, deduced a remarkable and seeming untenable conclusion from Fresnel's theory. He showed that a bright spot would be visible at the center of the shadow of a circular opaque obstacle; a result which he felt proved the absurdity of Fresnel's treatment.... This surprising prediction, fashioned by Poisson as the death blow to the wave theory, was almost immediately verified by Arago: the spot actually existed. Amusingly enough, Poisson's spot, as it is now called, had been observed many years earlier (1723) by Maraldi but this work had long gone unnoticed.<
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