Harald88 you are mixing up everything again like an autodidact and you don t want to listen You know once again everything in advance and much better than anybody else What you are stating here however is nonsense again The classical forerunner of SRT has been optics of moving bodies a discipline dealing with the observation of point source from a moving platform which is governed by Bradley s law of velocity aberration A point source emits spherical waves not plane waves In none of the references stated in the nonsensible Wikipedia article on the transverse Doppler effect to which you have contributed a proof is delivered but it is simply asserted there that the transverse Doppler effect has been unknown in classical physics In dozens of textbooks this nonsense is repeated without proof because authors tend to write off from one another Proofs of the nonsense are delivered in Chapter 11 of J D Jackson s book on clsssical electrodynamics as well as in a German book on SRT by Greiner Rafelski who probably have copied the deduction offered in Jackson s book who himself probably got that deduction from somewhere else These deductions boil down to direct betrayal of naive students because the students are made to believe that a point source such as a fixed star does emit plane waves rather than spherical waves Nobody tells them that the plane wave approximation is only an approximation and that it is therefore completely useless to prove something ia a context of paramount importance The nonsense of the non existing classical Doppler effect spreads in the literature since Einstein published in 1907 a short note where he had stated that the transverse Doppler effect which already Stark wanted to measure why if it is unknown in classical optics of moving bodies is important but not that it is unknown in classical physics It apparently has to do with the hystery which seems to capture most people who get in touch with the special relativity nonsense In reality SRT departs from classical optics of moving bodies solely for the case of longitudinal observation This I was going to demonstrate in the article Modern Galilean relativity Because of your unprofessional interference with that article I stopped today contributing to it Since you have the big mouth and know everything better I suggest that you finish the article now