An optical perspective on the theory of relativity -Ⅴ: Perihelion precession

The refractive index is redefined by using a metric tensor representing the structure of space-time, which mathematically unifies the idea of a gravitational field with that of a general optical medium. The differences and similarities between a gravitational field and a general medium are analyzed from the point of view of space structure deformation and it is proved that a gravitational field is just a more complex and special kind of medium. A local radius that can represent the degree to which the spatial structure of a gravitational field is bent is defined. A new formula for perihelion precession is then obtained by using the gravitational field refractive index and local radius. This is verified by taking Mercury as an example. The derivation of the new formula is simple and intuitive and offers a new perspective on the theory of relativity.