Americans John C. Mather and George F. Smoot won the Nobel Prize in Physics for 2006 on Tuesday, October 3, 2006.

The scientists were awarded the Prize "for their discovery of the black body form and anisotropy of the cosmic microwave background radiation," the Royal Swedish Academy of Sciences in Stockholm said.

The Physics Prize is awarded for work that helped look back at the infancy of the universe and to help the understanding of galaxies and stars. It is based on measurements made with the COBE satellite launched by NASA in 1989.

The COBE results provided increased support for the Big Bang scenario for the origin of the Universe. Immediately after the Big Bang, the Universe was like a glowing "black body emitting radiation in which the distribution across different wavelengths depends solely on its temperature. The shape of the spectrum of this kind of radiation has a special form known as blackbody radiation. When it was emitted, the temperature of the Universe was almost 3,000 degrees Centirgrade. Since then, the radiation has gradually cooled and now corresponds to temperature that is barely 2.7 degrees above absolute zero."

The first results from COBE were received after nine minutes of observations: COBE had registered a perfect blackbody spectrum. When the curve was shown at a later astronomical conference, the results received a standing ovation.

COBE also had the task of seeking small variation of temperature in different directions ("anisotropy")---in the range of hundredths of thousdanths of a degree. The variations in temperature show how the matter in the early universe began to aggregate into galaxies, clusters and superclusters that we see today.