Robert Woodrow Wilson | Biography

Robert Woodrow Wilson was born in Houston, Texas, on January 10, 1936. He attended Rice University where he received a B.A. in physics in 1957. He then moved on to the California Institute of Technology (Caltech) for graduate study and received his Ph.D. in 1962. Wilson's thesis work, and post-doctoral research, involved making radio surveys (the use of radio waves bounced off of stellar bodies to create visual approximations) of the Milky Way Galaxy. When he heard of the existence of specialized radio equipment at Bell Laboratories, he left Caltech and accepted a job at Bell's research facility in Holmdel, New Jersey. Wilson and Arno Penzias, who had preceded Wilson at Bell Labs by about a year, were about to embark on a research odyssey that would culminate in an extremely important discovery almost by accident.

Wilson and Penzias were studying the possible causes of static interference that impaired the quality of radio communications. Their research instrumentation included a small, sensitive twenty-foot microwave "horn" originally designed to receive bounced radio reflections from the Echo communications satellite. Very early in the research project, it became apparent that the antenna was measuring more radio radiation than Wilson and Penzias had anticipated. The source of the excess radiation could not be determined. A similar problem had surfaced earlier when the twenty-foot horn was used for Echo satellite communications. At that time, researchers added up all the known sources of accounted radio noise, which totaled a heat measurement of nineteen degrees Kelvin. It was therefore puzzling to them that the radio receiver was measuring twenty-two degrees. Wilson and Penzias checked for possible explanations for this phenomenon. The attempts to improve the performance of the radio horn took time. Finally, in 1965, the antenna was re-activated and careful observations were made of the radio flux from the sky. The results revealed that the telescope was performing better than ever, but the mysterious excess signal remained. The intensity of the excess radio noise was what would be expected from an object, or source, with a very low temperature, almost near absolute zero. Furthermore, in this case as with the previous observation, the static was not coming from a discrete source but was emanating uniformly from every direction in the sky.

While Wilson and Penzias were trying to make sense of what seemed to them to be a failed experiment, Robert Dicke and his colleagues at Princeton University, unaware of the project at Bell Labs, were building a radio receiver of their own designed to look for the very radiation that Wilson and Penzias had unintentionally observed. Whereas Wilson and Penzias had rather modest hopes of making simple surveys of galactic radio flux, Dicke was looking for physical evidence of the creation of the universe. Dicke had been researching the theoretical effects of the big bang, the expanding fireball theorized as the birth of the universe.

How could this "primeval fireball," as it came to be called, be observed today? If the remnant of this energy flash had survived after several billion years, it would be detected as a kind of "whisper" in a radio telescope. It would have a specific color and temperature and would be present in nearly equal intensities in every direction, forming a cosmic background radiation. This radiation would flood every available volume of space. In time, the radiation would appear to cool down to a point near absolute zero, due to the further expansion of the universe, but it would still be detectable even in the present-day universe. It was precisely this radiation that Robert Dicke was preparing to look for with his own radio telescope. It was also this radiation, measuring close to absolute zero (around three degrees Kelvin) in uniformity across the sky, that Wilson and Penzias had already discovered. When Dicke heard the details of their findings, he knew that Wilson and Penzias had discovered exactly what he was looking for: the cold, background radiation left over from the big bang. In 1965, Wilson and Penzias published their results, and a companion paper written by Dicke, P. J. E. Peebles, P.G. Roll, and D. T. Wilkinson explained the profound cosmological implications of the finding.

The discovery of the cosmic background radiation was like finding the intact skeleton of a dinosaur. The radiation is a "fossil," an ancient relic from a time when the universe was barely 100,000 years old. The discovery of the radiation was to become the second great pillar upon which the big bang theory would rest, second only to the 1920s discovery of the expansion of the universe. The fact that the background radiation was predicted in advance of its discovery helped to strengthen the big bang theory, so much so that most competing theories about the birth of the universe, such as steady state, almost immediately fell away after 1965.

Wilson and Penzias's discovery was acclaimed by scientists around the world. In 1976, Wilson was named head of the Radio-Physics department of Bell Telephone. For his work on the cosmic background radiation he also received the Henry Draper Award, in 1977, from the National Academy of Sciences. In 1978, the importance of their achievement in the history of science was fully recognized when Wilson and Penzias shared the 1978 Nobel Prize in physics with Pytor Kapitsa.