Augustin-Jean Fresnel
Fresnel submits his diffraction prize memoir to the Académie des Sciences
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Original prompt & settings (JSON) ↗He handed it in three days before the deadline, signed with nothing but a motto: Natura simplex et fecunda.
Three days before the deadline
On 29 July 1818 Augustin-Jean Fresnel presented his Mémoire sur la diffraction de la lumière to the Académie des Sciences in Paris.
It entered the competition for the Académie's 1819 biennial physics Grand Prix, whose submission deadline was 1 August 1818.
The Académie had announced diffraction as the prize problem on 17 March 1817, and François Arago and André-Marie Ampère encouraged Fresnel to enter.
What the memoir argued
Fresnel combined Huygens's wave construction with interference to give a mathematical explanation of diffraction fringes and of how little light penetrates the geometrical shadow.
It was not a restatement of Thomas Young: it removed Young's questionable reliance on reflection at an obstacle's edge and explained the fringes through interference among disturbances from different parts of a wavefront.
The entry was anonymous, identified only by the motto Natura simplex et fecunda — "Nature is simple and fertile" — until the sealed authorship note was opened.
The famous part happened later
No prize was awarded that day. Judging ran into 1819, and the committee — Arago, Siméon Denis Poisson, Pierre-Simon Laplace, Jean-Baptiste Biot and Joseph Louis Gay-Lussac — awarded the prize unanimously on 15 March 1819.
Poisson's derivation of a bright point at the centre of a circular obstacle's shadow, and Arago's test of it, belong to that review rather than to 29 July. Earlier experimenters had already observed the spot, so it was not an unprecedented phenomenon — deriving it from Fresnel's equations is what made it striking.
The full memoir was not printed in the Académie's Mémoires until 1826, at pages 339–475 of volume 5.
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Checked against
- Académie des Sciences—catalogue of Fresnel's published works
- Fresnel, Mémoire sur la diffraction de la lumière—Académie scan
- Principles of Optics—Elements of the Theory of Diffraction
- Issues in Optical Diffraction Theory—NIST Journal of Research
- Académie des Sciences—350 Years of Science: Fresnel and Poisson's Bright Spot
- Fresnel—Association Française de Génie Civil
- Was Poisson's Spot an Intentional Discovery?
- Arago's 1819 report on the diffraction competition