The Settlement Origin of the Arrow of Time: Two-Phase Information Conservation and the Emergence of Irreversibility

Abstract
The origin of the arrow of time—why entropy always increases, why we can only remember the past—is one of the deepest puzzles in physics. Boltzmann’s statistical explanation attributes entropy increase to a low-entropy “past hypothesis,” but it does not explain the origin of this initial condition itself. Landauer’s principle reveals a quantitative connection between information erasure and heat dissipation, yet it does not answer why information erasure is fundamentally irreversible. This paper proposes a unified solution within the two-phase information conservation framework: the arrow of time is the macroscopic statistical manifestation of the irreversibility of information settlement between the material phase (Ξ) and the information phase (Ω). Each information settlement event simultaneously produces four outcomes: formation of an information record, local collapse of the material phase state, update of observer coherence parameters, and consumption of dark energy accompanied by heat release. Once settlement is completed, it cannot be undone; the unidirectional flow of time is precisely the macroscopic bookkeeping of this settlement irreversibility. Starting from the principle of least action incorporating two-phase coupling, we provide a rigorous proof that the settlement process is not invariant under time reversal, and derive a quantitative relation between the entropy production rate and the macroscopic information activity rate. This framework unifies the thermodynamic arrow, the quantum measurement arrow, the decoherence arrow, and the cosmological arrow as manifestations of the same settlement process at different scales, offering a natural explanation for the past hypothesis and the entanglement past hypothesis. We present three testable predictions: a weak dependence of the CHSH violation parameter on the measurement time difference in Bell experiments, a scaling relation between decoherence rate and information-phase coupling strength at ultra-low temperatures, and the gravitational memory effect as a cumulative signature of settlement records on cosmological scales. This work unifies the arrow of time with quantum measurement, black hole information processing, dark energy cosmology, quantum entanglement, the Higgs mechanism, and the third law of thermodynamics under a single cross-scale information settlement paradigm.
Keywords: arrow of time, second law of thermodynamics, Landauer’s principle, information settlement, irreversibility, entropy increase, time-reversal symmetry breaking, gravitational memory effect, past hypothesis