 Robert Woodrow Wilson

Robert Woodrow Wilson and Arno Allan Penzias measured an unexplained microwave signal using a horn-reflector antenna and a receiver compared with a cooled reference. Their 1965 paper reported excess antenna noise that was approximately isotropic, unpolarized and seasonally stable.

They tested contributions from the atmosphere, instrumental losses and ground pickup before identifying the residual. Its interpretation as cosmic microwave background connected a carefully calibrated radio measurement to the thermal history of the Universe. The initial excess antenna temperature was not itself a full measurement of the background's blackbody spectrum.^[ref]

Robert Woodrow Wilson is an American astrophysicist who was awarded the Nobel Prize in Physics in 1978, along with Arno Penzias, for their discovery of cosmic microwave background radiation. This discovery provided crucial evidence for the Big Bang theory, fundamentally enhancing our understanding of the universe’s origins and evolution. Wilson and Penzias conducted experiments using a radio antenna, which led to the unexpected detection of a faint background noise that was later identified as the remnants of the hot early universe.