"On the colored light of double stars and certain other stars of heaven" and what happened hence

Christian Doppler, born 1853 as the second son of a stonemason-family in Salzburg, studied mathematics and physics and became Professor in Prague and in Vienna. In 1842 he described in a short theoretical study the relation of the waves of light of double stars and derived a simply formula and shows the deviation of the waves by the movement of the stars. In hard scientific discussions the correctness and the value of this simple formula was in doubt. In the zenith of his life and career he became Professor and Director of the new founded Institute of Physics of the University of Vienna. But although he was 49 years old, his health was so bad and he retired. In the following year he died. About 100 years later, since 50 years, the principle he described becomes importance by the introduction of ultrasound, radar-technique, etc.