The Torsion of a Ray of Light in a Continuous Isotropic Refracting Medium

Abstract

The vertical plane at a point A of the Earth’s surface, also containing another point B on it, is given form in Geodesy by means of the light path which joins such points, and since the path is in general curved, the exact definition of such a vertical plane depends:

• a). in the case when the light path can be considered plane, on the inclination of its plane with respect to the vertical plane considered;

• b). in the case when the light path cannot be considered as plane, on its torsion, as well as on the inclination of its osculating plane at A, with respect to the vertical plane considered.

Originally published as: Marussi A (1953) La torsione di una traiettoria luminosa in un mezzo rifrangente continuo isotropo. Atti Fond Giorgio Ronchi 1st Naz Ottica, anno VIII: no 2, March to April 1953