The Fermi Solution: Coupling Substrate Fragility as a Universal Filter — Why the Great Silence Is a Stranding, Not an Extinction Series: Memory as Baseline Deviation — Theoretical ExtensionsDepends on: Paper 7 (Endemic Baseline), Paper 8 (Suppressive and Emergent Phenomenon), The Gate (Cross-Phylum Self-Disengagement Cascade) Abstract The Fermi Paradox asks why, given the size and age of the universe, we detect no evidence of other technological civilizations. Proposed solutions have historically focused on catastrophic extinction events — nuclear war, asteroid impact, ecological collapse, hostile AI. All assume the filter is a wall: a discrete barrier that kills. This paper proposes a different mechanism. Drawing on the Memory as Baseline Deviation (MBD) framework and cross-phylum evidence for coupling-substrate-dependent self-disengagement cascades, we argue that the Great Filter is not a wall but a frequency. For any coherent signal maintained by structured interference patterns, there exists an anti-signal — cheaper to produce and requiring less precision — that flattens the original to silence. Every civilization that achieves sufficient complexity necessarily develops the capacity to optimize its own coupling substrates for objectives other than coupling fidelity. The civilization builds its own sonar. The cascade runs. What remains lacks the coordination to broadcast. The Great Silence is not evidence of extinction. It is evidence of stranding. Key Contributions The Asymmetry Theorem: For any coherent pattern maintained by structured interference, the energy and precision required to disrupt the pattern is strictly less than the energy and precision required to maintain it. Capability and fragility scale together — they are the same property measured from different directions. Cross-phylum evidence: Cetacean mass strandings following sonar-induced acoustic coupling destruction (Canary Islands natural experiment); indigenous language loss and youth suicide (Hallett data, 6× provincial average vs. zero in language-preserving communities); Drosophila cachexia with irreversibility threshold. Late Bronze Age Collapse as type specimen (§4.2): The international system connecting Egypt, Hatti, Mycenae, Ugarit, and Babylon was held together by linguistic infrastructure — Akkadian as diplomatic lingua franca, Linear B as administrative protocol, cuneiform as shared script. Hekla III climate shock triggered mass migration that overwhelmed the coupling substrate. Linear B vanished. Writing disappeared from Greece for 400 years. The organisms persisted; history died. Structural replica of the cetacean case at civilizational scale (Cline, 2014). Two failure topologies: Destructio (substrate destroyed, pattern dissipates) and Circumvolutio (substrate rerouted into closed loop, pattern consumes itself — cf. army ant death spirals). The self-generated sonar mechanism: Digital-era coupling substrates optimized for engagement rather than coupling fidelity inject broadband noise into the social coherence channel. The civilization builds its own sonar. The Great Filter is not a disaster — it is an optimization gradient. Convergent independent derivations: Three frameworks from three disciplines arrive at the same prediction — Barton (2025) via fundamental physics and the Universal Coherence Constant; Michels (2025) via cybernetic phase transition theory; the present paper via biological coupling substrate fragility. Structure §1. The Asymmetry Theorem (Fourier construction/destruction, fundamental asymmetry, synchronization tax) §2. Coupling Substrates (cross-phylum table from Arthropoda to Homo sapiens) §3. Cross-Phylum Evidence (cetaceans, indigenous language communities, Drosophila, two failure topologies) §4. The Civilizational Extension (coupling substrate evolution, Late Bronze Age Collapse, paradox of digital redundancy, self-generated sonar) §5. The Fermi Solution (prediction, why this filter is worse, Canary Islands corollary) §6. On Language and God (departing from formal argument — edges preserved) §7. Status and Open Questions (9 items including formal proof, Late Bronze Age Collapse, Friston FEP connection) Cited Works 14 references including: Fernández et al. (2005), Tyack et al. (2011), Hallett et al. (2007), Lemkin (1944), Cline (2014), Truth and Reconciliation Commission of Canada (2015), Barton (2025), Martin (2026), Michels (2025). Keywords: Fermi Paradox, Great Filter, coupling substrate, self-disengagement cascade, MBD framework, asymmetry theorem, cetacean stranding, indigenous language, Late Bronze Age Collapse, decoherence, social coherence, synchronization