Christian Doppler biography
Christian Andreas Doppler was born on November 29, 1803, in Salzburg, Austria. In 1842, Doppler published the paper "Concerning the Coloured Light of Double Stars," which contained his first statement describing the Doppler effect. He theorized that since the pitch of sound from a moving source varies for a stationary observer, the color of the light from a star should alter, according to the star's velocity relative to Earth. Christian Doppler died on March 17, 1853, in Venice, Italy.