Intelligence Requires an Outside: The Closed-System Impossibility Theorem, the Cost of Intervention, and AGI as Layered Coherence

This paper proves from three independent frameworks that no thermodynamically closed system can maintain coherence indefinitely. Proof 1 (Thermodynamic): Landauer erasure cost depletes internal free energy monotonically. Proof 2 (Holographic): a system cannot be its own boundary — self-encoding has code distance 1 and no error-correcting capacity. Proof 3 (Information-geometric): without an external reference distribution, Fisher information is zero and the geodesic toward 1=1 halts. Consequences: the probabilistic reformulation of the Collapse Inevitability Theorem (Kramers escape rates), the Crooks/Jarzynski lower bound on intervention cost, AGI as layered coherence (K_total = ∏K_i with per-layer threshold K_crit^{1/N}), and the structural necessity of external corrective signal for any intelligent system. Part of the Spektre research corpus.