I Why does reversibility require equilibrium?

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Reversibility in thermodynamic processes requires equilibrium because irreversible processes generate entropy and involve finite rates of mass, momentum, and heat transfer, which cannot be undone without affecting the surroundings. Research indicates that mass transfer occurs through diffusion, momentum transfer involves viscous dissipation, and heat transfer happens via conduction, all contributing to entropy generation within the system. The discussion highlights the importance of understanding these concepts in the context of statistical mechanics, particularly referencing Mehran Kerdar's work. Additionally, there is a request for resources on Boltzmann's H theorem, indicating a desire for further learning on the topic. Understanding these principles is crucial for grasping the nature of thermodynamic processes.
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my question is short simply why reversibility requires equilibrium?
 
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What research have you done about this question? Can you post links to your reading that led to this question? Thanks.
 
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berkeman said:
What research have you done about this question? Can you post links to your reading that led to this question? Thanks.
I was studying mehran kerdarbook on statistical mechanics of particles
 
In irreversible processes, transport of mass, momentum and heat occur at finite rates, and these cannot be reversed for the system without also bringing about a net change in the surroundings. Mass transfer involves diffusion at finite rates. Momentum transfer involves viscous dissipation of mechanical energy to internal energy and involves finite viscous stresses at finite deformation rates. Heat Transfer involves heat conduction at finite temperature gradients. All of these involve entropy generation within the system, rather than entropy transport via heat flow across the boundary of the system.
 
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Chestermiller said:
In irreversible processes, transport of mass, momentum and heat occur at finite rates, and these cannot be reversed for the system without also bringing about a net change in the surroundings. Mass transfer involves diffusion at finite rates. Momentum transfer involves viscous dissipation of mechanical energy to internal energy and involves finite viscous stresses at finite deformation rates. Heat Transfer involves heat conduction at finite temperature gradients. All of these involve entropy generation within the system, rather than entropy transport via heat flow across the boundary of the system.
Where can I learn about boltzmann's H theorem?
 
I don’t even know what that is.
 
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