Augustin Jean FresnelBorn 10 May 1788; died 14 Jul 1827 at age 39.French physicist who first investigated the effect of interference of light, with results known as Fresnel fringes. This decisive work, together with further experiments with polarized light, supported Thomas Young's wave theory of light. Fresnel advanced the wave theory by identifying light as transverse waves rather than the longitudinal waves previously assumed by Young and Christiaan Huygens. His pioneering work in optics included showing that white light is composed of a spectrum of innumerable wavelengths ranging from red to shorter violet wavelenths. In 1819, he improved the optical system of lighthouses by replacing metal reflectors with revolutionary stepped lenses of his design.« |
