Arno Allan Penzias
1933–2024, Munich, Germany, San Francisco, California, United States
American radio astronomer who, with Robert Wilson, discovered the cosmic microwave background; they received the 1978 Nobel Prize in Physics.
Penzias was born in Munich to a Jewish family and came to the United States in 1940 after escaping Nazi Germany with his family. He studied at the City College of New York, served in the U.S. Army Signal Corps, and earned a physics PhD from Columbia University in 1962. At Bell Labs, he and Robert Wilson used the Holmdel horn antenna to measure faint radio signals from the sky.
In 1965 they reported a nearly isotropic microwave signal that could not be explained by instrumental noise or known galactic sources. It was identified as the cosmic microwave background, thermal radiation left from the early universe. Penzias and Wilson shared the 1978 Nobel Prize in Physics; his German birthplace does not alter his American scientific and professional affiliation.
Nobel-winning work
Penzias shared half of the 1978 Nobel Prize in Physics with Wilson 'for their discovery of cosmic microwave background radiation'. In 1964–65, calibrating the Holmdel horn antenna, they found an excess 3.5 K noise at 4080 MHz that no terrestrial source could explain — identified by Dicke's group as the relic radiation of the hot Big Bang predicted by Gamow, Alpher and Herman (1948).
Workplaces: Bell Telephone Laboratories, Princeton University
United States