Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Entropy and the Second Law of Thermodynamics

Entropy and the Second Law of Thermodynamics

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 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...

Second Law of Thermodynamics

Second Law of Thermodynamics

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 chemical energy...

Second Law of Thermodynamics

Second Law of Thermodynamics

In the quest to identify a property that may reliably predict the spontaneity of a process, a promising candidate has been identified: entropy. Processes that involve an increase in entropy of the system (ΔS > 0) are very often spontaneous; however, examples to the contrary are plentiful. By expanding consideration of entropy changes to include the surroundings, a significant conclusion regarding the relation between this property and spontaneity may be reached. In thermodynamic models, the...

Entropy

Entropy

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.
When an ideal gas expands isothermally, the disorder in the gas increases. From the molecular perspective, the gas molecules have more volume to move around in.
Consider an infinitesimal step in the expansion, which...

Entropy

Entropy

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...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Stochastic heat engine using a single Brownian ellipsoid.

Physical review. E·2026

Same author

Role of extracellular vesicle-mediated neurodegeneration in substance use disorders.

Current opinion in physiology·2026

Same author

From global flocking to local clustering: Interplay between velocity alignment and visual perception of active particles.

The Journal of chemical physics·2026

Same author

Consideration of Pre- and Postanesthetic Evaluation During ECT in Cases of Isolated Eosinophilia in Endemic Regions.

The journal of ECT·2026

Same author

A Hypothesis-Generating Pharmacologic Profile for Sargramostim Treatment of Parkinson's Disease.

Cellular and molecular neurobiology·2026

Same author

Enhanced urine glucose sensing using two-dimensional TMDCs-based SPR biosensor.

Scientific reports·2026

Same journal

Tension on dsDNA bound to ssDNA-RecA filaments may play an important role in driving efficient and accurate homology recognition and strand exchange.

Physical review. E, Statistical, nonlinear, and soft matter physics·2016

Same journal

Publisher's Note: Amplitude-phase coupling drives chimera states in globally coupled laser networks [Phys. Rev. E 91, 040901(R) (2015)].

Physical review. E, Statistical, nonlinear, and soft matter physics·2016

Same journal

Erratum: Shapes of sedimenting soft elastic capsules in a viscous fluid [Phys. Rev. E 92, 033003 (2015)].

Physical review. E, Statistical, nonlinear, and soft matter physics·2016

Same journal

Erratum: Attenuation of excitation decay rate due to collective effect [Phys. Rev. E 90, 022142 (2014)].

Physical review. E, Statistical, nonlinear, and soft matter physics·2016

Same journal

Publisher's Note: Role of connectivity and fluctuations in the nucleation of calcium waves in cardiac cells [Phys. Rev. E 92, 052715 (2015)].

Physical review. E, Statistical, nonlinear, and soft matter physics·2016

Same journal

Publisher's Note: Lattice Boltzmann approach for complex nonequilibrium flows [Phys. Rev. E 92, 043308 (2015)].

Physical review. E, Statistical, nonlinear, and soft matter physics·2016

See all related articles

Search research articles

Related Experiment Video

Updated: Jun 21, 2026

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides

Published on: May 29, 2018

Entropy production theorems and some consequences.

Arnab Saha¹, Sourabh Lahiri, A M Jayannavar

¹S. N. Bose National Center For Basic Sciences, JD-Block, Sector III, Saltlake, Kolkata 700098, India.

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

|August 8, 2009

Summary

This summary is machine-generated.

This study analyzes entropy production fluctuations in solvable models, finding detailed fluctuation theorems apply even during transient states. Averaged entropy production offers a superior bound for work performed compared to the Jarzynski equality.

More Related Videos

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

Published on: May 30, 2014

Related Experiment Videos

Last Updated: Jun 21, 2026

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides

Published on: May 29, 2018

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

Published on: May 30, 2014

Area of Science:

Statistical Mechanics
Non-equilibrium Thermodynamics
Information Theory

Background:

Entropy production is a key measure of irreversibility in thermodynamic processes.
Fluctuation theorems provide insights into the statistical behavior of entropy production.
Understanding transient states and finite-time processes is crucial for realistic systems.

Purpose of the Study:

To investigate total entropy production fluctuations in exactly solvable models.
To analyze the nature of entropy production during system relaxation to equilibrium.
To evaluate averaged entropy production as a bound for work and an information-theoretic quantifier.

Main Methods:

Analysis of exactly solvable models in statistical mechanics.
Application of detailed fluctuation theorems to transient states.
Comparison of averaged entropy production with the Jarzynski equality.

Main Results:

Detailed fluctuation theorems are shown to hold in transient states for initially equilibrated systems.
Averaged entropy production over finite intervals provides a tighter bound for average work than the Jarzynski equality.
Average entropy production is discussed as a quantifier for information-theoretic irreversibility in finite-time nonequilibrium processes.

Conclusions:

Exactly solvable models provide a robust framework for studying entropy production fluctuations.
The findings offer improved methods for bounding work performed in nonequilibrium processes.
Entropy production serves as a valuable tool for quantifying information-theoretic irreversibility.