Americans win Physics Nobel for 'Big Bang' work

Americans John C Mather and George F Smoot won the 2006 Nobel Prize in physics today for work that helped shed more light on the beginning of the universe and the origin of galaxies and stars.

The scientists were awarded the prize for discovering the nature of 'blackbody radiation,' cosmic background radiation believed to stem from the 'Big Bang' when the universe was created, the Royal Swedish Academy of Sciences in Stockholm said.

Their work was based on measurements done with the help of the NASA-launched Cosmic Background Explorer satellite in 1989. They were able to observe the universe in its early stages about 3,80,000 years after it was born. Ripples in the light they detected also helped demonstrate how galaxies came together over time.

By confirming the predictions of the Big-Bang theory, which states the universe originated in an explosion from a point of infinite density billions of years ago, with direct quantitative evidence, the scientists transformed the study of the early universe from a largely theoretical pursuit into a new era of direct observation and measurement.

"The very detailed observations that the laureates have carried out from the COBE satellite have played a major role in the development of modern cosmology into a precise science," the academy said in its citation.

Mather, 60, works at the NASA Goddard Space Flight Center in Greenbelt, Maryland, and Smoot, 61, works at the Lawrence Berkeley National Laboratory in Berkeley, California.

The fact that their findings were cemented in 1989, and considered for the award this year, was a change from previous awards for topics that were often discovered decades earlier.