- Astronomy & Space Science
- Penzias, Arno Allan (1933– )
Penzias, Arno Allan (1933– )
German-born U.S. radio engineer who shared the 1978 Nobel Prize for Physics with Robert Wilson for their discovery of cosmic microwave background radiation.The existence of this radiation had been predicted on the basis of the Big Bang model of the origin of the universe, and its detection represents some of the strongest evidence in favor of this model.
Penzias was born in Munich, Germany, on April 26, 1933. To escape the Nazi persecution of Jews, his parents immigrated with him to the United States; all were later naturalized. Studying at the City College of New York (CCNY), Penzias earned his bachelor's degree in physics in 1954. He then continued his studies at Columbia University in New York, where he was awarded his master's degree in 1958 and his doctorate in 1962. In 1961 Penzias joined the Radio Research Laboratory of the Bell Telephone Company. From then to 1972 he was a staff member of the radio research department, and from 1972 to 1974 he was head of the technical research department. He then became head of the radiophysics research department before, in 1976, becoming director of the Radio Research Laboratory. In 1979 he became executive director of research and communication sciences at Bell Telephone Laboratories, and in 1989 vice president of research. In 1995 he became vice president and chief scientist of A.T.&T. Bell Laboratories, and retained his position when Bell Labs split from AT&T and became part of Lucent Technologies. In 1997 he retired from Bell, and later became involved with several high-technology companies in the Silicon Valley area.
In addition to his posts in the telecommunications industry, Penzias has also concurrently held a series of academic positions. The first of these was as lecturer in the department of astrophysical science of Princeton University 1967–82. He was appointed an associate of the Harvard College Observatory in 1968, a visiting professor at Princeton University in 1972, adjunct professor at the State University of New York (SUNY) at Stony Brook in 1975, and made trustee of Trenton State College in New Jersey in 1976.
Penzias's many important contributions to radio astronomy have brought him widespread acclaim. He received the Henry Draper Medal of the National Academy of Sciences in 1977, the Herschel Medal of the Royal Astronomical Society in 1977, and in 1978, with Robert Wilson and Pyotr Kapitza, the Nobel Prize for Physics.
In 1963 Penzias and Wilson were assigned by the Bell Telephone Company to the tracing of radio “noise” that was interfering with the development of a communications program involving satellites. By May 1964 the two had detected a surprisingly high level of radiation at a wavelength of 7.3 cm/2.9 in, which had no apparent source (that is, it was uniform in all directions, or isotropic). They excluded all known terrestrial sources of such radiation and still found that the noise they were detecting was a hundred times more powerful than could be accounted for. They also found that the temperature of this background radiation was 3.5K (−269.7°C/−453.4°F), later revised to 3.1 K (−270°C/−454.1°F).
They took this enigmatic result to Robert Dicke, a professor of physics at Princeton University. Dicke was interested in microwave radiation and had predicted that this sort of radiation should be present in the universe as a residual relic of the intense heat associated with the birth of the universe following the Big Bang. His department was then in the process of constructing a radio telescope designed to detect precisely this radiation, at a wavelength of 3.2 cm/1.3 in, when Penzias and Wilson presented their data.
Since then, background radiation has been subjected to intense study. Its spectrum conforms closely to a black-body pattern and its temperature is now known to be just under 3 K (− 270°C/−454°F). For cosmologists this constitutes the most convincing evidence in favor of the Big Bang model for the origin of the universe, although it also raises some fundamental questions, such as the possible “oscillation” of the universe between total contractions and total expansions.
Penzias's later work has been concerned with developments in radio astronomy, satellite communications, atmospheric physics and related matters. It was, however, for his work on the black-body background radiation that he received the Nobel Prize.
From the Hutchinson Dictionary of Scientific Biography, © RM, 2020. All rights reserved. Published under license in AccessScience, © McGraw-Hill Education, 2000–2020. Helicon Publishing is a division of RM.