Refractive gravity and starlight deflection

General Relativity describes gravity as the curvature of spacetime. RSI proposes instead that gravity is a gradient in the refractive index of the Eternal Consonance. The refractive index (n) measures how much a medium slows light. Just as a glass lens bends light by slowing it, a mass creates a region of the medium where light travels more slowly. The medium is incompressible, so what changes near a mass is not its density but its tension, which the mass slackens; since c = √(Ξ / μ), lower tension means slower light. Unlike glass, which bends blue light more than red, this bending is the same for every frequency, as radio and optical measurements at the Sun confirm.

The paper defines the refractive index of the vacuum at distance r from a mass M as n(r) ≈ 1 + 2GM/(rc²). It states that this recovers the physical effects of the Schwarzschild metric on a flat, Euclidean background.

As a test, the paper calculates the bending of starlight grazing the Sun. The Newtonian prediction of 0.87 arcseconds is incorrect. General Relativity and RSI's refraction model both give the observed 1.75 arcseconds.