This illustration shows how the light , although travelling at a constant c+v in the illustration frame,
is also travelling at variable speeds relative to the rotatng star source. This contradicts what is observed in MMx. In MMx light is shown to always travel at the same speed in all directions in the source frame.
The straight line across the illustration is the path of the "photon". The circular line is the path of the rotating stellar source. The numbers refer to where the light will be for each time frame where the time frame is an equal series of lengths of time .
So in frame 1 the light is just leaving the star. In frame 2 the light has travelled distance x from the source at (c+v) and the source has rotated 1/4 turn . In frame 3 the light has travelled the same distance x again and the light source has rotated another turn. Etc etc.
If one then takes the edge of a piece of paper and measures the orange lines linking 2-2, 3-3, 4-4, and 5-5 and then compares the lengths of each of them . One will find that the lengths are all different.
(1-2 is shorter than 2-3. 3-4 is shorter than 2-3 but longer than 1-2 and 4-5)
This shows that the distance travelled by the light from the source is travelling at a variable speed, relative to the source. Even though it is observed to be travelling at a constant speed c+v in the reference frame of the illustration .
In other words the illustration in wiki that this refers to is incorrect. Light does not travel at variable
speeds relative to the source. MMx shows us this and in fact there is no known experimental observation that shows that light travels at variable speeds relative to the source.
A correct illustration would be of the light source not moving and the earth/observor moving in a circular motion on the page. This would then show us that light does not pile up as it leaves the source. It would only have a doppler shift added to it at the point of observation.
