📓 In special relativity, the movements of the source and of the observer are equivalent. Though it is proved only that the speed of light does not depend from the source movement, basic postulate of special relativity states that the speed of light depends neither from the speed of the source nor on the speed of the observer. It is shown in the book, the movement of the observer is not equivalent to the movement of the source. In proposed experiments, the observer moving at speed V towards the source detects the speed of light C+V.