PRINCIPLE B - A NEW PHYSICAL FOUNDATION FOR THERMODYNAMIC IRREVERSIBILITY

The second law of thermodynamics states that isolated systems spontaneously evolve toward states of higher entropy. In Boltzmann’s statistical formulation, this behavior is interpreted as a consequence of the larger number of microstates compatible with high-entropy macrostates. However, this interpretation does not fully resolve conceptual difficulties related to Poincaré recurrence and the time-reversal invariance of microscopic laws. In this work, Principle B is introduced as a physical principle of irreversibility: an isolated system spontaneously evolves toward configurations of lower spatial energy concentration until a stable equilibrium state is reached. A discrete mathematical formalization is developed, showing that, under fixed total energy, the uniform distribution of energy corresponds to the stable minimum of a concentration functional. It is further shown that, within the adopted discrete framework, the state of minimum concentration coincides with the maximum number of compatible microstates and therefore with maximum Boltzmann entropy. Principle B is thus proposed as a possible physical foundation for thermodynamic irreversibility. Keywords: thermodynamic irreversibility; entropy; Boltzmann entropy; Principle B; energy concentration; equilibrium; statistical thermodynamics