Smoot, George Fitzgerald, III (1945-…), an American physicist, won a share of the 2006 Nobel Prize in physics for his research on the heat left over from the early universe. Scientists call this heat the cosmic microwave background (CMB) radiation. Smoot shared the prize with the American physicist John C. Mather, who also studied the CMB radiation. Smoot and Mather’s work forms part of a branch of physics and astronomy called cosmology, the study of the universe and its origin.
Smoot studied the CMB radiation for clues about the structure of the early universe. According to the big bang theory, the universe began in a cosmic explosion called the big bang that occurred about 14 billion years ago. The CMB radiation formed about 400,000 years later. At the time, the universe still existed in an extremely hot, dense state. Matter was spread throughout the universe much more evenly than it is today. However, for modern galaxies to form, certain regions of the early universe had to contain slightly more matter than others. As the universe expanded, these denser regions grew into the vast groups of galaxies that are observed today. The denser regions would have given off radiation with a slightly higher temperature than would the less dense regions. Scientists thought that, as a result, the CMB radiation might show tiny variations in temperature.
Smoot led a team that studied data collected by the Cosmic Background Explorer (COBE) satellite, launched in 1989. The COBE satellite included an instrument called a radiometer that measured the temperature of the CMB radiation coming from different directions in space in fine detail. In 1992, Smoot and his team reported that they had found the slight temperature variations. The discovery confirmed that galaxies could have grown from small clumps of matter in the early universe.
Smoot was born on Feb. 20, 1945, in Yukon, Florida. He received his doctorate degree in physics from the Massachusetts Institute of Technology in Cambridge in 1970. In 1971, Smoot began conducting research at the Lawrence Berkeley National Laboratory at the University of California at Berkeley.
See also Big bang; Cosmic microwave background (CMB) radiation; Mather, John Cromwell.
