Everyone know that only light wave could create relativistic Doppler Effect, and this because it was told that light wave required no physical medium for its propagation (how could it be something like that!). Any way, if it is so and if we could prove that actually light wave indeed propagates via some kind of physical medium, then it means that we could found relativistic Doppler Effect for sound wave, right? Here in the paper “Completed Einstein special theory of relativity”, we will show that sound wave or any kind of wave could create relativistic Doppler Effect. Please see detail in “Completed Einstein special theory of relativity” now present in
www.vacuum-mechanics.com .