On The Constancy Of The Velocity Of Light

In that distant time the postulate of independence of the light's speed directly confirmed only by astronomical observations of double stars. The idea of the Dutch astronomer Willem de Sitter, if the speed of light depends on the velocity of the source, the trajectory of motion of binary stars would have to be qualitatively different from those observed (consistent with celestial mechanics). In this part of the book gives examples and formulas for calculating the speed of light.