The Single Boundary of Expressibility: _Planck Regimes, Singularities, and Quantum Theory as One Limit Condition_

This thesis claims that modern 'breakdown points' in fundamental physics - Planck/ultraviolet regimes, spacetime singularities, the Big Bang limit, and black hole horizons/interiors - are not merely analogous failures of classical description. They are the same boundary, literally: a single boundary on articulated existence. 'Articulated existence' means existence as physically differentiable: the domain in which distinctions can be stably recorded and mutually compared, so that propositions are truth-apt. The boundary is comprised of pure undifferentiation, which is not a thing, not a state, and not a hidden realm. It is a limit condition: the point at which the prerequisites for articulation - discriminability, stable recordability, and comparability - cease to apply. Therefore there is nothing beyond the boundary: no further facts, no further states, and no further events, because 'fact/state/event' are forms of articulation that fail at that limit. Quantum theory is the lawful form of description on the articulated side of this boundary. Its characteristic features - superposition, incompatibility, and irreducible probabilities - express a world in which unlimited classical differentiation is not available. Apparent paradoxes of self-reference and observer dependence arise when one demands a single globally completed classical truth assignment across contexts that cannot be jointly embedded into one arena of record comparison. On this view, Planck limits and singularities do not point to different mysteries; they are different coordinate approaches to one and the same termination of articulation.