Irreversible process
thermodynamic process that is not reversible
In thermodynamics, an irreversible process is a process impossible to reverse or undo. All complex natural processes are irreversible, although a phase transition at the coexistence temperature (e.g. melting of ice cubes in water) is well approximated as reversible.
A change in the thermodynamic state of a system and all of its surroundings cannot be precisely restored to its initial state by infinitesimal changes in some property of the system without expenditure of energy. A system that undergoes an irreversible process may still be capable of returning to its initial state. Because entropy is a state function, the change in entropy of the system is the same whether the process is reversible or irreversible. However, the impossibility occurs in restoring the environment to its own initial conditions. An irreversible process increases the total entropy of the system and its surroundings. The second law of thermodynamics can be used to determine whether a hypothetical process is reversible or not.
Intuitively, a process is reversible if there is no dissipation.
Begin with the source’s own compact description: “Irreversible process” is thermodynamic process that is not reversible. The dossier treats that line as a proposition to test through Irreversible, process and thermodynamic, not as a finished interpretation.
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