Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Entropy02:39

Entropy

26.3K
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...
26.3K
Entropy01:18

Entropy

2.8K
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...
2.8K
The Entropy as a State Function01:14

The Entropy as a State Function

135
Consider an arbitrary process that moves between two specific states (A and B) in a cyclic manner. This process is reversible and broken down into smaller parts that each follow a Carnot cycle. A Carnot cycle has two isothermal (constant temperature) processes. During these processes, the ratio of the amount of heat transferred to their respective temperature remains constant. The other two processes in the Carnot cycle are also reversible but adiabatic, which means they occur without any heat...
135
Entropy and the Second Law of Thermodynamics01:20

Entropy and the Second Law of Thermodynamics

3.3K
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...
3.3K
Entropy and the Second Law of Thermodynamics01:26

Entropy and the Second Law of Thermodynamics

384
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...
384
Entropy Change in Reversible Processes01:10

Entropy Change in Reversible Processes

2.4K
In the Carnot engine, which achieves the maximum efficiency between two reservoirs of fixed temperatures, the total change in entropy is zero. The observation can be generalized by considering any reversible cyclic process consisting of many Carnot cycles. Thus, it can be stated that the total entropy change of any ideal reversible cycle is zero.
The statement can be further generalized to prove that entropy is a state function. Take a cyclic process between any two points on a p-V diagram.
2.4K

You might also read

Related Articles

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

Sort by
Same author

Emergence of Haldane Pseudo-Potentials in Systems with Short-Range Interactions.

Journal of statistical physics·2020
Same author

Divergence of the Effective Mass of a Polaron in the Strong Coupling Limit.

Journal of statistical physics·2020
Same author

Rigidity of the Laughlin Liquid.

Journal of statistical physics·2019
Same author

Entropy meters and the entropy of non-extensive systems.

Proceedings. Mathematical, physical, and engineering sciences·2014
Same author

Possible lattice distortions in the hubbard model for graphene.

Physical review letters·2011
Same author

Energy cost to make a hole in the Fermi sea.

Physical review letters·2011
Same journal

Computational modelling distinguishes diverse contributors to aneurysmal progression in the Marfan aorta.

Proceedings. Mathematical, physical, and engineering sciences·2025
Same journal

Inferring the shape of data: a probabilistic framework for analysing experiments in the natural sciences.

Proceedings. Mathematical, physical, and engineering sciences·2023
Same journal

The Elbert range of magnetostrophic convection. I. Linear theory.

Proceedings. Mathematical, physical, and engineering sciences·2022
Same journal

Soft wetting with (a)symmetric Shuttleworth effect.

Proceedings. Mathematical, physical, and engineering sciences·2022
Same journal

The quantum theory of time: a calculus for q-numbers.

Proceedings. Mathematical, physical, and engineering sciences·2022
Same journal

Integrable nonlinear evolution equations in three spatial dimensions.

Proceedings. Mathematical, physical, and engineering sciences·2022
See all related articles

Related Experiment Video

Updated: May 7, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
11:03

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

Published on: December 4, 2017

7.6K

The entropy concept for non-equilibrium states.

Elliott H Lieb1, Jakob Yngvason

  • 1Department of Mathematics , Princeton University , Princeton, NJ 08542, USA ; Department of Physics , Princeton University , Princeton, NJ 08542, USA.

Proceedings. Mathematical, Physical, and Engineering Sciences
|October 9, 2013
PubMed
Summary
This summary is machine-generated.

This study extends the entropy principle for classical thermodynamics to non-equilibrium states. While a unique entropy is not generally possible, two functions, S- and S+, define the limits of adiabatic processes.

Keywords:
entropynon-equilibrium thermodynamicssecond law of thermodynamics

More Related Videos

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides
09:41

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

Published on: May 29, 2018

8.8K
Experimental Investigation of Secondary Flow Structures Downstream of a Model Type IV Stent Failure in a 180° Curved Artery Test Section
11:00

Experimental Investigation of Secondary Flow Structures Downstream of a Model Type IV Stent Failure in a 180° Curved Artery Test Section

Published on: July 19, 2016

10.3K

Related Experiment Videos

Last Updated: May 7, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
11:03

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

Published on: December 4, 2017

7.6K
Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides
09:41

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

Published on: May 29, 2018

8.8K
Experimental Investigation of Secondary Flow Structures Downstream of a Model Type IV Stent Failure in a 180° Curved Artery Test Section
11:00

Experimental Investigation of Secondary Flow Structures Downstream of a Model Type IV Stent Failure in a 180° Curved Artery Test Section

Published on: July 19, 2016

10.3K

Area of Science:

  • Thermodynamics
  • Statistical Mechanics
  • Physical Chemistry

Background:

  • The second law of classical thermodynamics is foundational to understanding energy transfer and irreversibility.
  • Previous work established an axiomatic derivation of entropy for equilibrium states, linking its increase to adiabatic process possibility.

Approach:

  • Reviews the axiomatic foundation for equilibrium entropy.
  • Investigates the definition of entropy for non-equilibrium states.
  • Introduces the concept of state comparability for adiabatic changes.

Key Points:

  • A unique, universally applicable entropy function for non-equilibrium states is generally not feasible.
  • Two distinct entropy functions, S- and S+, are proposed.
  • These functions, S- and S+, together delineate the possible range of adiabatic processes between non-equilibrium states.

Conclusions:

  • The definition of entropy for non-equilibrium systems presents significant challenges.
  • The proposed S- and S+ functions offer a framework for analyzing adiabatic processes in non-equilibrium scenarios.
  • Comparability of states is crucial for understanding adiabatic transformations beyond equilibrium.