In his 1803 paper Fundamental Principles of Equilibrium and Movement, the French mathematician
The … See more

In 1865, Clausius named the concept of "the differential of a quantity which depends on the configuration of the system", entropy (Entropie) after the Greek word for 'transformation'. He gave "transformational content" (V… See more

The concept of entropy is described by two principal approaches, the macroscopic perspective of classical thermodynamics, and the microscopic description central to statistical mechanics. The classical approach d… See more

The second law of thermodynamics requires that, in general, the total entropy of any system does not decrease other than by increasing the entropy of some other system. Hence, in a system isolated from its environ… See more

The entropy of a system depends on its internal energy and its external parameters, such as its volume. In the thermodynamic limit, this fact leads to an equation relating the change in the internal energy to changes in … See more

For certain simple transformations in systems of constant composition, the entropy changes are given by simple formulas.
For the expansion (or compression) of an ideal gas from … See more