Arno Penzias

Arno Penzias, a German-American astrophysicist, was educated at the City College of New York and Columbia University, where he earned a PhD in 1962, and then joined Bell Labs in Holmdel, New Jersey. Working with Robert Wilson from 1964 to monitor radio emissions using a sensitive horn antenna originally built for satellite communication research, he detected a faint, uniform microwave signal coming from every direction in the sky that neither could explain as instrument noise, ruling out even pigeon droppings inside the antenna as a cause. Consulting with a nearby Princeton group led by Robert Dicke, who were independently building equipment to search for exactly this kind of radiation, predicted decades earlier as a relic of an early hot, dense universe, the signal was identified as the cosmic microwave background, direct evidence for the big bang. Penzias shared the 1978 Nobel Prize in Physics with Wilson for the discovery.