A novel extension of Quantum Mechanics: Entropy, Irreversibility, and the Quantum-Classical Transition

Göran Lindblad

Reddy Govind

We extend Barandes’ indivisible stochastic interpretation of quantum mechanics to address the emergence of classical spacetime and the arrow of time from collective quantum processes. While Barandes (2025) demonstrates that individual quantum sys- tems can be understood as indivisible stochastic processes, we show that when many such systems interact, their collective behavior generates emergent spatial structure through quantum correlations and emergent temporal divisibility through thermody- namic irreversibility. Specifically, we argue that: (1) spatial relations emerge from patterns of quantum entanglement and correlation among multiple actualizations; (2) thermodynamic entropy production in many-body systems creates an irreversible ar- row of time; (3) this irreversibility transforms the fundamentally indivisible quantum process into an apparently divisible classical process; and (4) the time parameter t itself emerges as a bookkeeping device for tracking these irreversible collective changes. This framework provides a unified account of the quantum-to-classical transition, connect- ing quantum foundations, statistical mechanics, and emergent spacetime in a coherent picture where both space and time arise from the collective dynamics of indivisible quantum actualizations.

G. C. Ghirardi

Kenneth Searcy

If these constraints hold, physical theories must take the form they do. This paper evaluates how established physical theories relate to a set of foundational constraints derived without physical assumptions. Building on prior work that establishes the necessity of transition, irreversibility, probabilistic constraint, temporal order, and entropy as logical requirements for nontrivial describable ontology, it examines whether classical mechanics, thermodynamics, quantum mechanics, and relativity instantiate, approximate, or presuppose these structures. Rather than proposing new physics or modifying existing theories, the paper adopts an explicitly evaluative stance. Each theory is assessed according to whether it supports irreversible transition, structured possibility, ordered asymmetry, and monotonic entropy understood as irreversible constraint accumulation. Particular attention is given to quantum mechanics as a stress test, showing that probabilistic transition and irreversible measurement instantiate the derived constraints independently of interpretive commitments. The analysis demonstrates that successful physical theories do not escape these foundational constraints, and that apparent tensions arise only from idealized formalisms or interpretive abstractions. The framework thus serves as a diagnostic lens for understanding why physical theories must take the forms they do, rather than as a replacement for empirical physics.

N. V. Lunin, Vladimir I Kogan

Jonah Brent

Decoherence and thermodynamic irreversibility are widely regarded as sufficient to explain the emergence of classical behavior from quantum mechanics. Decoherence suppresses interference between branches of the wavefunction, while entropy production provides a direction to macroscopic time. However, neither mechanism alone explains why macroscopic physics exhibits a single, persistent, globally consistent classical history rather than fragmentation into mutually incompatible record sets. In this work, we identify and formalize this unresolved issue as the classicality gap. We show that in finite systems subject to nonzero noise and irreversible record formation, decoherence and entropy production are generically insufficient to stabilize a single coherent macroscopic history. Instead, absent a history-level selection mechanism, redundant records diverge and macroscopic identity becomes ill-defined. We present a general instability result demonstrating this fragmentation tendency and introduce history-level constraint restoration as the minimal structural mechanism capable of preventing it. This mechanism operates without new microdynamics, collapse postulates, or observer dependence. We derive qualitative phase boundaries separating stable and unstable regimes and propose concrete experimental protocols on NISQ-era quantum platforms that can falsify the necessity of history selection. Our results establish that persistent classicality is not guaranteed by decoherence alone, but requires selection acting on histories under irreversible constraints. Keywords: classicality emergence, decoherence limits, record inconsistency, history instability, quantum-to-classical transition, irreversibility, entropy production, information persistence, open quantum systems, foundations of physics