I posted this on Google+ earlier, but it seemed worthwhile to expand it into a blog post.
Augustin-Jean Fresnel (1788-1827) is, in my opinion, one of the underappreciated giants in optical physics. Though Thomas Young’s double slit experiment was the first one to demonstrate the wave nature of light, it was the later efforts of Fresnel that put the wave properties of light on firm theoretical footing and really popularized the idea.
The famous and important part of Fresnel’s life involves the 1819 Prize Contest of the Académie des Sciences. At that point, most scientists were still convinced that light was fundamentally a particle, not a wave, phenomenon; the prize committee was so convinced that they posed as the prize question an explanation of diffraction, fully expecting someone to propose a corpuscular explanation that would vindicate their views. Fresnel, however, explained the observed diffraction phenomena using his painstakingly-formulated wave theory. One of the members of the committee, Poisson, argued that Fresnel’s theory predicted an impossible result: a bright spot of light in the direct shadow of an opaque disk. Fresnel’s friend Arago did the experiment, however, and confirmed that “Arago’s spot” in fact does occur! This dramatic demonstration marked the turning point in scientific opinion in favor of the wave theory of light.
Having had such a powerful influence on the world of science, one might expect that Fresnel had an auspicious youth — however, is only partly true! After Fresnel’s passing, his good friend François Arago wrote a biography of him and presented it at the 1830 meeting of the Académie; it includes the following striking passage.
Augustine John Fresnel was born the 10th of May, 1788, at Broglie, near Bernay, in that part of the ancient province of Normandy which now forms the department of Eure. His father was an architect, and in this quality had been entrusted by the military engineer with the construction of the Fort of Querqueville, at one of the extremities of the harbour of Cherbourg; but the revolutionary storm having forced him to abandon this work, he retired with all his family to a moderate property which he owned near Caen, at Matthieu, a little village which already was not without some notoriety, being the birthplace of the poet John Marot, father of the celebrated Clement. Madame Fresnel, whose family name (Mérimée) was also to become one day dear to literature and the arts, was endowed with the most happy qualities of heart and mind; the solid and varied instruction which she had received in her youth enabled her to assist actively, during eight consecutive years, in the efforts which her husband made for the education of their four children. The progress of the eldest son was brilliant and rapid. Augustine, on the contrary. advanced extremely slowly in his studies; at eight years of age he could scarcely read. This want of success might be attributable to the very delicate condition of the young scholar, and to the precautions which it rendered necessary; but it will be still better understood when it is known that Fresnel never had any taste for the study of languages; that he always set very little value on the exercises which address themselves solely to the memory; that his own, which was moreover very rebellious generally, refused almost absolutely to retain words from the moment that they were detached from a clear argument and displaced in arrangement: I must also own, without hesitation, that those whose predictions concerning the future of a child are founded on the precise estimate of the first places which he obtained at the college, in theme or in translation, would never have imagined that Augustine Fresnel would become one of the most distinguished savants of our epoch. As to his young comrades, they had, on the contrary, judged with that sagacity which rarely deceives them: they called him “the genius.” This pompous title was unanimously accorded him on account of the experimental researches (I may be allowed this expression, it is but just) to which he devoted himself at the age of nine years, whether for determining the relative length and bore which give the greatest power to the little elder-wood popguns which children use in their play, or in determining which are the woods, dry or green, which are best to use in making bows, under the double consideration of elasticity and strength. The physicist of nine years old had, indeed, executed this little work with so much success, that the toys, hitherto very inoffensive, had become dangerous arms, which he had the honour of seeing proscribed by an express resolution of the assembled parents of all the combatants.
I’ve emphasized two passages here. The first: Fresnel, later to be a paradigm-shifting theoretical physicist, could hardly read at age eight! Though I would not presume that I am on the same level as Fresnel, I’m reminded of the fact that I nearly failed algebra in junior high, but nevertheless am now a theoretical physicist myself.
The second passage demonstrates that genius can manifest itself in many different ways: the young Fresnel managed to “improve” the toys of his youth so well that the neighborhood parents needed to ban the weaponry!
Fresnel is yet another example demonstrating that one should not look for intelligence in too narrow a manner. The next revolution in science may come from anyone, with any sort of unusual background.