Irreverzibilitás

Irreverzibilitás refers to the property of a process or phenomenon that cannot be undone or reversed to its original state. In thermodynamics, it is closely linked to the second law, which states that the total entropy of an isolated system can only increase over time, or remain constant in ideal cases where the system is in a steady state or undergoing a reversible process. Real-world processes, such as the mixing of gases, heat transfer from a hotter to a colder body, or friction, are inherently irreversible. Once these processes occur, the system moves to a new state of higher entropy, and returning to the original state would require external work and result in an increase in entropy elsewhere in the universe.

This concept extends beyond physics. In chemistry, reactions that proceed to completion and cannot be easily reversed are considered irreversible. For example, the combustion of fuel is largely an irreversible process. In economics, certain decisions or events can have irreversible consequences, meaning the economy cannot simply revert to its previous condition without significant intervention or a long period of adjustment. In a broader sense, irreversibility implies a one-way street of change, where time's arrow dictates a progression that cannot be rewound. The degree of irreversibility can vary, with some processes being more easily reversed than others, but absolute reversibility is a theoretical ideal rarely encountered in practice.