| Description | Explaining to Mr Eisner what 'aberration' is i.e. 'Aberration is not related to the motion of the source of the light; it is not given by the relative velocity between source and receiver. Instead it is merely the change in angle of a light-ray described in one coordinated system when you change to one in a different state of motion. Thus, on the earth half a year later you are adopting a different (inertial, near enough) system and you have to make the necessary correction. That correction is aberration, and it is identically for all light-rays in your new system, since all light-rays, no matter ... what source, lie on the same light cone in your coordinate system'. |