Gravitational lensing is commonly described as the bending of light along curved spacetime geodesics. While this geometric formulation reproduces observations, it does not identify a direct physical interaction mechanism between light and mass. This standalone paper reformulates gravitational lensing as a refraction phenomenon driven by resonance gradients within USP Field Theory. By first examining light propagation in atomic and material media, the work builds a continuous physical bridge from ordinary refractive optics to planetary, stellar, and galactic-scale lensing. In the USP framework, light follows gradients in frequency mismatch (Δf) rather than spacetime curvature as a physical entity. The paper demonstrates how this mechanism reproduces standard lensing phenomenology while predicting potential frequency- and coherence-dependent signatures under extreme field gradients. An appendix extends the model with quantitative relations, spectral deformation effects, and a roadmap for observational tests using multi-band lensing data (e. g. , JWST). The document is designed to be fully standalone while remaining compatible with future theoretical and experimental upgrades. Equations (MS Word / linear format) You can paste these directly into Word’s equation editor: GR deflection angle: α ≈ 4GM / (c² b) USP frequency mismatch gradient: ∇Δf (r) ≠ 0 USP ray equation: d² r / ds² ∝ ∇Δf (r) Photon resonance shift: Δfₗight = f0 (1 − γg) Gradient factor: γg ∝ Tf / r² Deflection scaling: θ_Δf ∝ ∇ (Δf) Spectral deformation: Δfcolor = Δfₑmission − Δfₚath
Sadegh Sepehri (Sun,) studied this question.