Grimaldi, Francesco Maria (fränchāsˈkō märēˈä grēmälˈdē) [key], 1618?–1663, Italian physicist and mathematician. A Jesuit and professor at Bologna, he studied in detail and named the dark areas on the moon. Noted for his discoveries in the field of optics, he was the first to describe the diffraction of light (in a posthumous work published 1665) and the first to attempt a wave theory of light.
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