(1933–    ), German-American astrophysicist and Nobel laureate. Born in Munich, Penzias (and his family) came to the U.S. in 1940. He was educated at City College (now part of the City University of New York) and Columbia University, where he received his Ph.D. in 1962. He became an American citizen in 1946. While at Columbia, under the direction of the American physicist Charles Townes, he built a maser amplifier for a radio-astronomy project. He was a radar officer in the Army Signal Corps from 1955 to 1956, and he went to work at Bell Laboratories in Holmdel, N.J., in 1961. His early research was in the field of satellite communications, but he later transferred his attention to radio astronomy. In 1964 Penzias and Robert W. Wilson, a colleague at Bell Laboratories, began using a radio telescope to monitor radio waves in the Milky Way galaxy. In 1965, they announced the discovery of 3 K (–454° F) cosmic background radio emission, which has been used to support the big bang theory of the origin of the universe (see Background Radiation; Cosmology). In the late 1960s Penzias and Wilson made further advances in radio astronomy, particularly in the study of the origins of chemical elements. Penzias held a number of managerial positions at Bell Laboratories; he became vice president for research in 1981.

In 1978 Penzias and Wilson shared half of the Nobel Prize in physics; the Soviet physicist Peter L. Kapitza received the remaining half. Penzias and Wilson were cited for “their discovery of cosmic microwave background radiation.” Penzias’s notable book on the technology and its role in society, Ideas and Information, was published in 1989.

See also Inflationary Theory.