THE SANNER MODEL — The Dark Matter Illusion as Optical Artifact and Non-Linear Aether Dynamics

Standard cosmology requires "dark matter" to explain flat galaxy rotation curves, the Baryonic Tully-Fisher Relation (BTFR), cluster lensing, and the Bullet Cluster. This paper proposes that dark matter is not a substance but an artifact of a kinematic aether. In The Sanner Model (TSM), space is rigid and mass acts as a sink for an accelerating aether. Light propagates at c relative to the aether, not the observer, and must fight the inward aether flow on its way out; astronomers misinterpret this headwind as excess stellar velocity. The exact relationship is derived, and TSM predicts an inferred missing mass of roughly 4.8 times the visible mass in the transition regime. More fundamentally, the non-linear TSM field equation, written in divergence form with an interpolating function μ(x), naturally produces the BTFR (M_bar ∝ v_obs⁴) with the correct slope of 4 and zero intrinsic scatter. The same response explains the Bullet Cluster, where the lensing gradient is dominated by the compact galaxy distribution rather than the diffuse gas, and predicts a family of rotation curve shapes determined by the baryonic mass distribution and the transition radius r_trans ∝ √(M_bar), including the Milky Way decline beyond ~15 kpc. The hypothesis is testable with existing data via the BTFR, the Radial Acceleration Relation, and cluster lensing, and directly testable with the proposed Aether Speedometer. Appendix B extends the reasoning to black holes, which in TSM are physical Black Spheres with finite-density cores rather than singularities, with observable consequences for gravitational-wave echoes.