19th century in science Carnot captured some of the ideas of thermodynamics in his discussion of the efficiency of an idealized engine. Sadi Carnot's work provided a basis for the formulation of the first law of thermodynamics—a restatement of the law of conservation of energy—which was stated around 1850 by William Thomson, later known as Lord Kelvin, and Rudolf Clausius. Lord Kelvin, who had extended the concept of absolute zero from gases to all substances in 1848, drew upon the engineering theory of Lazare Carnot, Sadi Carnot, and Émile Clapeyron–as well as the experimentation of James Prescott Joule on the interchangeability of mechanical, chemical,
19th century in science the length scale required for gravitational perturbations to grow in a static nearly homogeneous medium. In chemistry, Dmitri Mendeleev, following the atomic theory of John Dalton, created the first periodic table of elements. In 1859, Charles Darwin published the book "The Origin of Species", which introduced the idea of evolution by natural selection. The list of important 19th-century scientists includes: 19th century in science The 19th century in science saw the birth of science as a profession; the term scientist was coined in 1833 by William Whewell, which soon replaced the older term of (natural) philosopher. Among the most influential