Sadi Carnot, a French physicist, was the first to show the quantitative relationship between work and heat. Carnot was born in Paris on June 1, 1796, and was educated at the École Polytechnique in Paris and at the École Genie in Metz. His interests included mathematics, tax reform, industrial development, and the fine arts.
In 1824 he published his only work – Reflections on the Motive Power of Heat – which reviewed the industrial, political, and economic importance of the steam engine. In it he defined work as "weight lifted through a height." Carnot began to study the physical properties of gases in 1831, particularly the relationship between temperature and pressure.
On August 24, 1832, he died suddenly of cholera. In accordance with the custom of his time, all of his personal effects were burned. Some of his notes that fortunately escaped destruction indicate that Carnot had arrived at the idea that heat is essentially work, or work that has changed its form. For this reason, he is considered to be the founder of the science of thermodynamics, which states that energy can never disappear; it can only be altered into other forms of energy. Carnot's notes led Lord Kelvin to confirm and extend the science of thermodynamics in 1850.