Alice's Paradox A Win–Win Test of No-Signaling in GHZ Systems and the Operational Meaning of Reality

A GHZ state is globally maximal, yet every bipartite reduction is separable — mere classical correlation. The correlations are real, violate Bell inequalities, can be used for cryptography — and yet they have no address. They exist, but they are nowhere. This paper organizes everything around a single question: from their local data alone, can Bob and Charlie distinguish whether Alice measured or not? The no-signaling theorem says no. We propose a targeted, loophole-aware experimental protocol to test this — the first dedicated tripartite test of this specific configuration. The name carries a deliberate echo of Lewis Carroll: like her passage through the looking glass, Alice's measurement crosses an information boundary that separates what is real on one side from what is visible on the other. The looking glass is the boundary itself — non-orientable, as the paper shows. The proposal is win–win: A null result certifies a constraint on local fact-accessibility: a distant choice does not become local knowledge without crossing a causal frontier. The most parsimonious ontological reading is boundary-first: physical information is organized on relational boundaries, not distributed in the bulk. A non-null result, after excluding post-selection artifacts, setting-dependent losses, and side-channels, would indicate new physics — a breakdown of at least one among operational linearity, completeness of local description, or relativistic causality. The paper provides a complete experimental blueprint (loophole analysis, statistical protocol based on total variation distance with permutation tests, resource estimates) implementable with current optical-GHZ technology. Beyond the operational analysis, we extract an ontological implication through systematic elimination of five alternative readings. A key insight: all alternatives that fail share a common error — they presuppose information must have a spatial address. The surviving hypothesis recognizes that the relational structure is the fundamental description, and 'the bulk' is derivative. The strongest objection ("you are merely renaming the global state") is addressed explicitly: that the global state is not reconstructible from marginals is a theorem; that the parts are derivative is an ontology. The anti-realism position receives careful, respectful treatment: it is logically coherent but not generative — it closes inquiry where the boundary-first reading opens it. The ontological direction converges independently with the programme of Fields, Glazebrook, and Marcianò (2022), who show that the holographic principle is a structural consequence of quantum information theory. Alice's Paradox proposes how to test this consequence in the laboratory. The analysis extends to N-particle GHZ states, where the paradox amplifies with scale: arbitrarily large entangled systems become trivially classical when one particle is traced. The steering manifold — the space of conditional decompositions accessible through Alice's basis choice — has the topology of RP², a non-orientable surface with measurable monodromy. The GHZ system is the minimal laboratory witness of a structural property that, if general, applies from laboratory systems to cosmological scales. This paper is part of an interconnected corpus of nine works developing a boundary-first framework for quantum foundations, emergent gravity, and cosmology. Version history: v1.0 (January 9, 2026): Initial version, 4-paper corpus. v2.0 (January 19, 2026): Updated corpus (6 papers), revised abstract. v3.0 (February 2026): Major philosophical revision. Rewritten treatment of anti-realism (from dismissal to respectful engagement). New sections: "Independent Convergence" (Fields et al.), "common error" meta-pattern, "renaming objection," boundary terminology for finite systems. Corpus updated to 8 papers. Operational definitions tightened. Conclusions restructured. v4.0 (February 19, 2026): Final revision for arXiv submission. Rovelli's relational QM integrated as philosophical backdrop (§1.6). Physics/metaphysics boundary sharpened throughout. Historical silence question addressed explicitly (§6.4), including honest acknowledgment that the reading may have been considered and dismissed. Del Santo/Brukner references on Wigner's friend and impossible measurements woven into the argument. Lewis Carroll footnote explaining the name. Corpus updated to 9 papers. Typographic cleanup (widow/orphan control, clean page breaks). Appendix D (corpus overview) removed per reviewer feedback. Keywords: quantum foundations, holographic principle, GHZ states, no-signaling theorem, boundary-organized information, falsifiable experiment, tripartite entanglement, quantum ontology, information boundaries, eliminative abduction, RP² steering topology