Nicolas Léonard Sadi Carnot

Nicolas Léonard Sadi Carnot (French: [kaʁno]; 1 June 1796 – 24 August 1832) was a French military engineer and physicist, often described as the "father of thermodynamics". In his only publication, the 1824 monograph Reflections on the Motive Power of Fire, Carnot gave the first successful theory of the maximum efficiency of heat engines. Carnot's work attracted little attention during his lifetime, but it was later used by Rudolf Clausius and Lord Kelvin to formalize the second law of thermodynamics and define the concept of entropy.

Life

Nicolas Léonard Sadi Carnot was born in Paris into a family that was distinguished in both science and politics. He was the first son of Lazare Carnot, an eminent mathematician, military engineer and leader of the French Revolutionary Army. Lazare chose his son's third given name (by which he would always be known) after the Persian poet Sadi of Shiraz. Sadi was the elder brother of statesman Hippolyte Carnot and the uncle of Marie François Sadi Carnot, who would serve as President of France from 1887 to 1894.

Sadi Carnot

Sadi Carnot may refer to:

Carnot heat engine

A Carnot heat engine is an engine that operates on the reversible Carnot cycle. The basic model for this engine was developed by Nicolas Léonard Sadi Carnot in 1824. The Carnot engine model was graphically expanded upon by Benoît Paul Émile Clapeyron in 1834 and mathematically elaborated upon by Rudolf Clausius in 1857 from which the concept of entropy emerged.

Every thermodynamic system exists in a particular state. A thermodynamic cycle occurs when a system is taken through a series of different states, and finally returned to its initial state. In the process of going through this cycle, the system may perform work on its surroundings, thereby acting as a heat engine.

A heat engine acts by transferring energy from a warm region to a cool region of space and, in the process, converting some of that energy to mechanical work. The cycle may also be reversed. The system may be worked upon by an external force, and in the process, it can transfer thermal energy from a cooler system to a warmer one, thereby acting as a refrigerator or heat pump rather than a heat engine.

Carnot cycle

The Carnot cycle is a theoretical thermodynamic cycle proposed by Nicolas Léonard Sadi Carnot in 1824 and expanded upon by others in the 1830s and 1840s. It provides an upper limit on the efficiency that any classical thermodynamic engine can achieve during the conversion of thermal energy into work, or conversely, the efficiency of a refrigeration system in creating a temperature difference (e.g. refrigeration) by the application of work to the system. It is not an actual thermodynamic cycle but is a theoretical construct.

Every single thermodynamic system exists in a particular state. When a system is taken through a series of different states and finally returned to its initial state, a thermodynamic cycle is said to have occurred. In the process of going through this cycle, the system may perform work on its surroundings, thereby acting as a heat engine. A system undergoing a Carnot cycle is called a Carnot heat engine, although such a "perfect" engine is only a theoretical construct and cannot be built in practice.

Michel Serres

Michel Serres (born 1 September 1930) is a French philosopher and author.

Life and career

The son of a barge man, Serres entered France's naval academy, the École Navale, in 1949 and the École Normale Supérieure ("rue d'Ulm") in 1952. He aggregated in 1955, having studied philosophy. He spent the next few years as a naval officer before finally receiving his doctorate in 1968, and began teaching in Paris.

As a child, Serres witnessed firsthand the violence and devastation of war. "I was six for my first dead bodies," he told Bruno Latour. These formative experiences led him consistently to eschew scholarship based upon models of war, suspicion, and criticism.

Over the next twenty years, Serres earned a reputation as a spell-binding lecturer and as the author of remarkably beautiful and enigmatic prose so reliant on the sonorities of French that it is considered practically untranslatable. He took as his subjects such diverse topics as the mythical Northwest Passage, the concept of the parasite, and the explosion of the Space Shuttle Challenger. More generally Serres is interested in developing a philosophy of science which does not rely on a metalanguage in which a single account of science is privileged and regarded as accurate. To do this he relies on the concept of translation between accounts rather than settling on one as authoritative. For this reason Serres has relied on the figure of Hermes (in his earlier works) and angels (in more recent studies) as messengers who translate (or: map) back and forth between domains (i.e., between maps).