Irreversibility Originating from Information Compression: Re-evaluating Statistical Mechanics and the Second Law of Thermodynamics
Year: 2026
Type: other
Abstract: Under a complete microscopic description, fundamental physical evolution is reversible and information-preserving. The Poincaré recurrence theorem establishes that measure-preserving dynamical systems defined over finite-measure phase-space almost surely return arbitrarily close to their initial states within finite timescales. Unitary time evolution in quantum mechanics likewise enforces reversibility and exact conservation of quantum information. Nonetheless, macroscopic phenomena manifest robust irreversibility, which the second law of thermodynamics formalizes and statistical mechanics interprets as the system-wide tendency toward statistically most probable configurations. From an information-theoretic standpoint, this paper argues that irreversibility emerges from information compression implemented as a many-to-one (non-injective) mapping projecting the full state space onto the subspace accessible to observational procedures. Such mapping induces irrecoverable loss of information, rendering irreversibility a necessary consequence intrinsic to finite observers. Entropy increase in statistical mechanics constitutes an effective description constrained by finite observational windows; the thermodynamic arrow of time arises as an epistemically necessary artifact conditioned by observer-side structural limits. In contrast, projective quantum measurement operationally eliminates coherent phase information, yielding operationally genuine irreversibility rather than a purely descriptive artifact. Within this framework, the second law of thermodynamics is reinterpreted as an effective theory valid under finite-information descriptions. It holds within bounded observational windows yet is not an absolute fundamental law governing underlying microscopic physics. The heat-death scenario obtained by unbounded extrapolation of entropic growth represents a boundary effect within descriptive space instead of a genuine terminal physical state of the universe.
Author: Jiang
Language: English
Subfield: Statistical and Nonlinear Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7204950233