Time as a Boundary Condition, Not a Dimension A Constraint-Based Interpretation of Temporal Asymmetry

Time as a Boundary Condition, Not a Dimension presents a conceptual reinterpretation of time in physics, proposing that time is not a fundamental dimension through which systems evolve, but an emergent boundary formed by irreversible physical constraints. In this framework, the past is defined as excluded configuration space—states that are no longer physically accessible due to non-invertible processes such as measurement, decay, dissipation, or interaction—while the future remains an open set of unconstrained possibilities. The theory explains the arrow of time without invoking special initial conditions, grounds irreversibility in local physical processes rather than probability alone, and offers an intuitive reinterpretation of time dilation as a slowing of constraint accumulation under motion or gravity. Fully compatible with existing physical equations, this work reframes the ontological meaning of the time parameter in relativity and quantum mechanics, providing a unified, constraint-based explanation for temporal asymmetry, measurement irreversibility, and the experienced distinction between past, present, and future.