https://adrijanjosic.com/f/three-classical-tests-of-genrelativity-from-one-refractive-index https://adrijanjosic.com/f/the-grav-clock-rate-as-a-unifying-concept-in-intro-relativity https://adrijanjosic.com/f/mercurys-perihelion-advance-from-a-speed-budget