2021
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Entropy is a scientific concept that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynamics, where it was first recognized, to the microscopic description of nature in statistical physics, and to the principles of information theory.
Entropy is the loss of energy available to do work. Another form of the second law of thermodynamics states that the total entropy of a system either increases or remains constant; it never decreases. Entropy is zero in a reversible process; it increases in an irreversible process.
The second law of thermodynamics states that in a reversible process, the entropy of the universe is constant, whereas in an irreversible process, such as the transfer of heat from a hot object to a cold object, the entropy of the universe increases.
The total entropy, Eq. (2.6), may be written S total (E|T) = S(E) – E/T, and it isextremised at E = Ē(T) (suppressing N and V). The function S total (T) ≡ S total (E(T)|T) is the transformation of the entropy as a function of energy, S(E), to the entropy as a function of temperature, S total (T).
The second law of thermodynamics states that the total entropy of a system either increases or remains constant in any spontaneous process; it never decreases. An important implication of this law is that heat transfers energy spontaneously from higher- to lower-temperature objects, but never spontaneously in the reverse direction.
Entropy. In Equations ( 13.4.1) and ( 13.4.2 ), we have taken T1 and T2 to be the initial temperatures of the two systems, but in general, of course, these temperatures will change during the heat transfer process.
Entropy is a thermodynamic property just like pressure, volume, or temperature. Therefore, it connects the microscopic and the macroscopic world view. Boltzmann's principle is regarded as the foundation of statistical mechanics . Gibbs entropy formula.
