Fibonacci at the Threshold of Retention: Minimal Geometry, Physical Memory, and the Emergence of Form

This work interprets Fibonacci geometry as a diagnostic signature of physical retention, emerging near critical thresholds where form persists under minimal energetic surplus. It demonstrates that logarithmic spiral ordering coincides with the Genesis Window (SNR ≈ 0.1–0.2), marking regimes of retentive stability rather than growth optimization. The paper reframes Fibonacci patterns as observable markers of physical memory across microphysical, biological, and cosmological systems, introducing testable predictions within the framework of Retentive Physics.