SCIENCE PHOTO LIBRARY SCIENCE PHOTO LIBRARY
Christian Doppler. Portrait of Austrian physicist Christian Johann Doppler (1803-1853), discoverer of the Doppler effect. Doppler was educated in mathematics at the Vienna Polytechnic. He obtained a professorship in mathematics in Prague in 1841, then took the post of professor of experimental physics at Vienna in 1850. He is famous for the Doppler effect, proposed in 1842. This states that a stationary observer listening to a sound source will hear the sound at a higher pitch if the source is approaching, and a lower pitch when receding, than when the source is still. He later discovered this effect with light waves; Doppler shift measurements are used in modern cosmology.
Model release not available. Property release not required.