Wavefunction Collapse as Algorithmic Garbage Collection: Deriving the Born Rule from the Bennett-Landauer Bound

The Quantum Measurement Problem — the absence of any physical mechanism by which deterministic, unitary Schrödinger evolution transitions into a discrete, probabilistic classical outcome — remains the central open problem in the foundations of quantum mechanics. While environmental decoherence explains the suppression of quantum interference, it does not explain why or when a single outcome is realized. This paper resolves the measurement problem within the Algorithmic Theory of Reality (ATR). By treating the universe as a finite-bandwidth information-processing architecture, we demonstrate that wavefunction collapse is not a mystical observer effect, but a mandatory thermodynamic memory-management protocol. Key Results: The Collapse Threshold: We prove that when a microscopic superposition entangles with a macroscopic apparatus, the entanglement entropy grows until the local Bennett-Landauer processing cost exceeds the local holographic energy budget. This forces a non-unitary state truncation. Quantitative Timescale: The derived threshold yields a quantitative collapse timescale (τc) that mathematically matches the experimentally observed decoherence time. Derivation of the Born Rule: Given pointer-state orthogonality (from decoherence), we rigorously derive the Born Rule (pi = |ci|2) by formulating the forced state truncation as a constrained thermodynamic optimization problem that minimizes the Kullback-Leibler divergence (algorithmic information loss). Scale Unification: The exact same Bennett-Landauer limit that dictates the macroscopic boundaries of the universe (Dark Energy) and galaxies (the MOND scale) is shown to govern the microscopic limits of quantum coherence. The ATR framework mathematically determines when collapse must occur, with what statistics, and in which basis, reducing the single-outcome problem to a single, structurally necessary axiom (the Lüders update). Supplementary Material: The algebraic derivation of the Born Rule (via KL-divergence minimization and Lagrange multipliers), the exponential growth of entanglement entropy, and Monte Carlo statistical validations are independently reproducible via the companion computational verification script, available at: https://github.com/srdrymn/atr-verify-wavefunction-collapse