See also: 1849 in science, other events of 1850, 1851 in science and the list of years in science.
Physics Rudolf Clausius publishes his paper on the mechanical theory of heat, which first states the basic ideas of the second law of thermodynamics Hippolyte Fizeau and E. Gounelle measure the speed of electricity Léon Foucault demonstrates the greater speed of light in air than in water, and to establish that the speed of light in different media is inversely as the refractive indices of the media (see Fizeau-Foucault Apparatus) Awards Copley Medal: Peter Andreas Hansen Wollaston Medal: William Hopkins Births January 15 - Sofia Kovalevskaya, mathematician († 1891) May 18 - Oliver Heaviside, physicist († 1925) June 6 - Karl Ferdinand Braun, physicist († 1918) August 25 - Charles Richet, Nobel Prize winner († 1935) Deaths March 27 - Wilhelm Beer, astronomer (* 1797) May 10 - Joseph Louis Gay-Lussac, chemist and physicist (* 1778))
