Nicolas Léonard Sadi Carnot (1796-1832)

Nicolas Léonard Sadi Carnot (1796-1832)

A French scientist, physicist and military engineer. He was mostly known as the founder of the science of Thermodynamics.

Carnot was born on June 1,1796, in Paris, France. His father was Lazare Nicolas Marguerite Carnot.

At the age of eighteen, Sadi Carnot studied and graduated from École Polytechnique. Then, in the same year, he commissioned in Napoleon's army. After Waterloo, his father was exiled, and Carnot's army career and studies were interrupted for many years. Following his retirement as an army officer, he began studying and working on the processes involved in the operation of steam engines. In 1824, he described his interpretation of the perfect engine, with the Carnot engine. In this device, all available source of energy is utilized. He discovered that heat could not be transmitted form a colder to a warmer object and that the efficiency of an engine relies on the amount of heat it is capable of employing. This discovery was known as the Carnot cycle and is the basis of the second law of thermodynamics. It was an outstanding contribution to the theory of heat engines. He was able to anticipate this law with the first theoretical explanation of the efficiency of reversible steam engines.

In that same year (1824), he published his researches in his book Reflections on the Motive Power of the Fire. In that time, his discoveries and work were largely ignored. However, by 1834, they were recognized and accepted by society. In addition, his views were even incorporated in the thermodynamic theory, which was developed, in 1850, by Rudolf Clausius in Germany and Lord Kelvin in Britain. This work demonstrated that his contributions to understanding and interpreting the nature and mechanical equivalent of heat antedated those of Lord Kelvin, Julius Robert von Mayer, and James Prescott Joule.

Nicolas L. Sadi Carnot died on August 24, 1832, in Paris.