George Smoot

George Fitzgerald Smoot III (born February 20, 1945) is an American astrophysicist, cosmologist and Nobel Prize in Physics laureate for his work on COBE with John C. Mather that led to the measurement "...of the black body form and anisotropy of the cosmic microwave background radiation."

This work helped cement the big-bang theory of the universe using the Cosmic Background Explorer Satellite (COBE). According to the Nobel Prize committee, "the COBE-project can also be regarded as the starting point for cosmology as a precision science.

He is a professor of physics at the University of California, Berkeley. In 2003 he was awarded the Einstein Medal.


Smoot was born in Yukon, Florida. He graduated from Upper Arlington High School in Upper Arlington, Ohio in 1962. He studied mathematics before switching to the Massachusetts Institute of Technology where he obtained dual bachelor's degrees in mathematics and physics in 1966, and a Ph.D. in particle physics in 1970.

Although Smoot attended MIT, he was not the same Smoot who was laid end to end to measure the Harvard Bridge between Cambridge and Boston;this was his cousin Oliver R. Smoot, an MIT alumnus who served as the chairman of the American National Standards Institute.

Initial research

George Smoot then switched to cosmology, and went to Lawrence Berkeley National Laboratory where he collaborated with Luis Walter Alvarez on the experiment HAPPE, a stratospheric balloon for the detection of antimatter in the upper atmosphere, which was predicted by the now obscure steady state theory of cosmology.

He then took up an interest in cosmic microwave background radiation (CMB), previously discovered by Arno Allan Penzias and Robert Woodrow Wilson in 1964. There were, at that time, several open questions about this, relating directly to fundamental questions about the structure of the universe. Certain models predicted the universe as a whole was rotating, which would have an effect on the CMB: its temperature depending on the direction of observation. With the help of Alvarez and Richard A. Muller, Smoot developed a differential radiometer which measured the difference in temperature of the CMB between two directions 60 degrees apart. The instrument, which was mounted on a Lockheed U-2 plane, made it possible to determine that the overall rotation of the universe was zero, which was within the limits of accuracy of the instrument. It did, however, detect a variation in the temperature of the CMB of a different sort. That the CMB appears to be at a higher temperature on one side of the sky than on the opposite side, referred to as a dipole pattern, has been explained as a Doppler effect of the Earth's motion relative to the area of CMB emission, which is called the last scattering surface. Such a doppler effect arises because the Sun, and in fact the Milky Way as a whole, is not stationary, but rather is moving at nearly 600 km/s with respect to the last scattering surface. This is probably due to the gravitational attraction between our galaxy and a concentration of mass like the Great Attractor.


At that time, the CMB appeared to be perfectly uniform excluding the distortion caused by the Doppler effect as mentioned above. This result contradicted observations of the universe, with various structures such as galaxies, galaxy clusters, that indicate that the universe was relatively heterogeneous on a small scale. However, these structures formed slowly. Thus, if the universe is heterogeneous today, it would be heterogeneous at the time of the emission of the CMB as well, observable today through weak variations in the temperature of the CMB. It was the detection of these anisotropies that Smoot was working on in the late 1970s. He then proposed to NASA a project involving a satellite equipped with a detector that was similar to the one mounted on the U-2, but was more sensitive and not influenced by air pollution. The proposal was accepted and gave rise to the satellite COBE, and cost US$160 million. COBE was launched on November 18, 1989, after a delay owing to the destruction of the Space Shuttle Challenger. After more than two years of observation and analysis, the COBE research team announced on 23 April 1992 that the satellite had detected tiny fluctuations in the CMB, a breakthrough in the study of the early universe.The observations were "evidence for the birth of the universe" and Smoot said that "it's like looking at God."

The success of COBE was the outcome of prodigious team work involving more than 1,000 researchers, engineers and other participants. John Mather coordinated the entire process and also had primary responsibility for the experiment that revealed the blackbody form of the CMB measured by COBE. George Smoot had main responsibility for measuring the small variations in the temperature of the radiation.
Smoot collaborated with San Francisco Chronicle journalist Keay Davidson to write the general-audience book Wrinkles in Time, that chronicled his team's efforts.In the book The Very First Light, John Mather and John Boslough complement and broaden the COBE story as presented in Smoot's Wrinkles in Time.In this book Mather reported that George Smoot violated team policy by leaking news of COBE's discoveries to the press before NASA's formal announcement, a leak that, to Mather, smacked of self-promotion and betrayal. This report proved to be erroneous and Mather and Smoot have since reconciled.

Recent projects

After COBE, Smoot took part in another experiment involving a stratospheric balloon, MAXIMA, which had improved angular resolution compared to COBE, and refined the measurements of the anisotropies of the CMB. Smoot has continued CMB observations and analysis and is currently a collaborator on the third generation CMB anisotropy satellite Planck. He is also a collaborator in the design of the Supernova/Acceleration Probe (SNAP), a satellite which is proposed to measure the properties of dark energy.[14] He has also assisted in analyzing data from the Spitzer Space Telescope in connection with measuring far infrared background radiation.


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