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Entropy and the Second Law of Thermodynamics

Entropy and the Second Law of Thermodynamics

Consider an isolated system in which a hot object is placed in contact with a cold one. This is an irreversible process that eventually leads both objects to reach the same equilibrium temperature. It is crucial to note that the constituents of any substance exhibit increased disorder at higher temperatures. As a cold substance absorbs heat, its constituents become more disordered. The energy transfer from a hotter object to a cooler one increases the system's disorder or randomness. This...

Entropy and the Second Law of Thermodynamics

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The second law of thermodynamics can be stated quantitatively using the concept of entropy. Entropy is the measure of disorder of the system.
The relation between entropy and disorder can be illustrated with the example of the phase change of ice to water. In ice, the molecules are located at specific sites giving a solid state, whereas, in a liquid form, these molecules are much freer to move. The molecular arrangement has therefore become more randomized. Although the change in average...

Entropy

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Salt particles that have dissolved in water never spontaneously come back together in solution to reform solid particles. Moreover, a gas that has expanded in a vacuum remains dispersed and never spontaneously reassembles. The unidirectional nature of these phenomena is the result of a thermodynamic state function called entropy (S). Entropy is the measure of the extent to which the energy is dispersed throughout a system, or in other words, it is proportional to the degree of disorder of a...

Entropy

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The first law of thermodynamics is quantitatively formulated via an equation relating the internal energy of a system, the heat exchanged by it, and the work done on it. A quantitative formulation of the second law of thermodynamics leads to defining a state function, the entropy.
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Second Law of Thermodynamics

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The Second Law of Thermodynamics states that entropy, or the amount of disorder in a system, increases each time energy is transferred or transformed. Each energy transfer results in a certain amount of energy that is lost—usually in the form of heat—that increases the disorder of the surroundings. This can also be demonstrated in a classic food web. Herbivores harvest chemical energy from plants and release heat and carbon dioxide into the environment. Carnivores harvest the...

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An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

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Stochastic thermodynamics with information reservoirs.

Andre C Barato¹, Udo Seifert¹

¹II. Institut für Theoretische Physik, Universität Stuttgart, 70550 Stuttgart, Germany.

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics

|November 7, 2014

Summary

We introduce information reservoirs to stochastic thermodynamics, enabling work extraction from heat baths and modifying the second law. This generalization includes a new entropy production and linear response theory for information machines.

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Area of Science:

Thermodynamics
Information Theory
Statistical Mechanics

Background:

Stochastic thermodynamics governs systems with small numbers of particles.
The second law of thermodynamics traditionally limits energy transformations.
Information reservoirs offer new possibilities for energy manipulation.

Purpose of the Study:

To generalize stochastic thermodynamics by incorporating information reservoirs.
To investigate the impact of information reservoirs on the second law of thermodynamics.
To develop a new framework for information processing machines.

Main Methods:

Generalizing stochastic thermodynamics to include information reservoirs.
Deriving a new fluctuation theorem and entropy production.
Developing a linear response theory for information processing machines.

Main Results:

Work extraction from a single heat bath is possible with information reservoirs.
A generalized second law and information processing entropy production are derived.
Efficiency at maximum power for information machines can deviate from 1/2.

Conclusions:

Information reservoirs fundamentally alter thermodynamic laws.
The developed framework provides new insights into information-energy trade-offs.
This research opens avenues for novel information processing devices.