Fermi Transport

摘要

Figure 1. It shows the sphere of directionsin green, with three radial directions labeled1, 2, 3. The polarisation vectors are shownin red perpendicular to the radius vectorand therefore tangential to the sphere. Ifthe direction of a light ray changes from 1 to2 to 3 to 1, the polarisation vector is rotatedas shown. On its return to the 1 direction,the polarisation vector is as shown in blue,rotated relative to the initial polarisation shown in red. The angle of rotationis equal to the area of the geodesic triangle 1-2-3-1, which in this case is anoctant of the sphere 4S/8, i.e., S/2, which is a right angle.