2006 Nobel Prize in physics awarded for microwave map of the universe

October 3, 2006

John C. Mather of NASA and George F. Smoot of Lawrence Berkeley National Laboratory shared the 2006 Nobel Prize for Physics for "their discovery of the blackbody form and anisotropy of the cosmic microwave background radiation." The Nobel Prize Committee cited the physicists for their work on the Cosmic Background Explorer (COBE) project. COBE revealed fluctuations in faint microwave signals from space that are thought to be remnants of the Big Bang.

Although the precise origin of the fluctuations in the cosmic microwave background is not yet clear, they may represent clumps in the very early universe that led to the galaxies seen today.

Prior to the COBE map of the universe, it was unclear why the universe contained stars and galaxies rather than an evenly distributed dust cloud. Theorists had predicted that a sensitive measurement of microwaves from the sky would reveal minute temperature fluctuations, which represent variations in the density of matter in the early universe. The denser portions served as seeds for galaxies that formed later. COBE was the first experiment sensitive enough to confirm the predicted temperature variations encoded in the map of the microwave background.

The initial discovery of the Cosmic Microwave Background by Arno Penzias and Robert Wilson led to their award of the 1978 Nobel Prize in physics. Although they measured the approximate temperature of the universe to be about 3.5 kelvins, their ground-based microwave telescope could not pick out the detail available to COBE.