June 13, 2021
Waves can only be generated and propagate in a medium. The propagation of waves in the medium is independent of the motion of the source. In the empty space no waves can exist. In empty space only motions relative to the source and relative to the observer can be defined, therefore it has no sense to assume an independence of the motion of the emitted objects from the motion of the source (in empty space only particles can propagate). The velocity of the emitted objects in the empty space relative to the observer is always relative. The assumption of an absolute velocity is meaningless.