The Nobel Prize in Physics 2006 also goes to America

John C. Mather from NASA Goddard Space Flight Center in the US and George F. Smoot, professor from University of California, Berkeley USA have been awarded the Nobel Prize in Physics for 2006.

Professor Gunnar Oquist, Secretary General of the Royal Swedish Academy of Sciences made the announcement on Tuesday at a press conference in the Academy in Stockholm.

He said the two American scientists are awarded for their discovery of the blackbody form and anisotropy of the cosmic microwave background radiation.

"This year the physics prize is awarded for work that looks back into the infancy of the Universe and attempts to gain some understanding of the origin of galaxies and stars. It is based on measurements made with the help of the COBE satellite launched by NASA in 1989." Said Professor Oquist.

As Professor Lars Bergstrom explained, the COBE results provided increased support for the Big Bang scenario for the origin of the Universe, since this is the only scenario that predicts the kind of cosmic microwave background radiation measured by COBE. These measurements also marked the inception of cosmology as a precise science.

According to the Big Bang scenario, the cosmic microwave background radiation is a relic of the earliest phase of the Universe. Immediately after the big bang itself the Universe can be compared to a glowing "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 remitted the temperature of the Universe was almost 3000 degrees Centigrade. Since then, according to the Big Bang scenario, the radiation has gradually cooled as the Universe has expanded. The background we can measure today corresponds to a temperature that is barely 2.7 degrees above zero. The Laureates were able to calculate this temperature thanks to the blackbody spectrum revealed by the COBE measurements.

COBE also had the task of seeking small variations of temperature in different directions. Extremely small differences of this kind in the temperature of the cosmic background radiation- in the range of a hundred-thousandth of a degree-offer an important clue to how the galaxies came into being. The variations in temperature show us how the matter in the universe began to aggregate. This was necessary if the galaxies, stars and ultimately life like us were to be able to develop. Without this mechanism matter would have taken a completely different form, spread evenly throughout the Universe.

COBE was launched using its own rocket on November 18, 1989. The first results were received after nine minutes of observations: COBE had registered a perfect blackbody spectrum.

The Nobel Prize Committee thinks that the success of COBE was the outcome of prodigious team work involving more than 1000 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 microwave background radiation measured by COBE. George Smoot had main responsibility for measuring the small variations in the temperature of the radiation.

60 year old John C. Mather got his PhD in Physics in 1974 from the University of California at Berkeley and is senior astrophysicist at NASA's Goddard Space Flight Center, Greenbelt, MD.

61 year old George F. Smoot got his PhD in Physics in 1970 also from the University of California at Berkeley.

Over a telephone interview at the press conference, Professor Mather said he was amazed.

"I certainly feel thrilled, I am overwhelmed, it is a rare honor."

Asked whether he realized that he would have won the Nobel Prize, he said, "No, we didn't know how important it was then."

The laureates will share 10 million kronor, or about 1.37 million US dollars of the prize.

On Monday, Professor Audrew Z. Fire from Stanford University and Professor Craig C. Mello from Massachusetts Institute of Technology won the Nobel Prize in Physiology or Medicine 2006.

By Chen Xuefei, People's Daily Online Correspondent in Stockholm