Augustin-Jean Fresnel

Born in 1788, Fresnel was a French civil engineer who turned to physics in his thirties and began working on diffraction and polarization. He proposed that light waves are purely transverse, explained double refraction, and by the late 1830s his work had nearly erased Newton's particle model from serious consideration. The same rigor produced the Fresnel lens — a stepped reflective-refractive design that extended lighthouse range and became standard in maritime safety. Tuberculosis shadowed him throughout; he died at 39 in 1827, receiving the Royal Society's Rumford Medal on his deathbed. A co…