The Two-Boundary Universe: A Time-Symmetric, Information-Conserving Framework for Physics

Modern physics is built on the assumption that time only moves one way, beginning at the initial boundary (or initial condition), fixed effectively at the Big Bang. Our theories begin at that starting point and evolve from there. Yet the laws of nature work both forward and backward. This one-way view lies at the root of many of physics’ biggest puzzles, like wavefunction collapse, quantum “spookiness,” the arrow of time, and the clash between quantum mechanics and relativity. Two-Boundary Theory (2BT) proposes a minimal correction: the universe is a unique four-dimensional history jointly constrained by two real temporal boundaries, an initial (α) and a final (Ω). No new dynamics or hidden variables are added; the same lawful evolution operates in both directions, and the realized world is the intersection of the forward image of α with the backward image of Ω. From within time, partial knowledge of α and ignorance of Ω make outcomes appear stochastic and the future “open,” though the underlying history is globally deterministic and locally causal. This two-sided admissibility resolves the major paradoxes in a single move: Bell-level correlations arise from whole-trajectory consistency rather than superluminal influence; measurement collapse becomes an epistemic update, not a physical jump; and the arrow of time reflects asymmetric boundary information, not asymmetric law. The analysis preserves unitarity, covariance, and conservation principles intact. The paper confines itself to the conceptual and ontological core of the framework; later work develops the informational field Φ(t) and weighted-operator formalism that implement the same constraint mathematically. The result is an Ockham-minimal, time-symmetric completion of the scientific worldview: one reversible law, two boundaries, one consistent universe.