Astronomers map earliest light

Sunday, May 26, 2002

WASHINGTON -- Scientists analyzing tiny variations in the sky's background radiation have detected the earliest light emitted at the formation of the universe.

The detailed new images show indications of the first bits of matter that would evolve into the stars and planets that exist today.

"We have seen, for the first time, the seeds that gave rise to clusters of galaxies, thus putting theories of galaxy formation on a firm observational footing," said team leader Anthony Readhead of the California Institute of Technology.

"These unique high-resolution observations provide a new set of critical tests of cosmology," he said.

The research, detailed last week at a National Science Foundation briefing, was conducted using the Cosmic Background Imager, a set of 13 radio antennas located high in the Atacama Desert of Chile.

The instruments were able to detect minute variations in the cosmic microwave background, the radiation that has traveled to Earth over almost 14 billion years.

According to the researchers the fluctuations are indications of those first tentative seeds of matter and energy.

They added that the measurements provide evidence to support the theory of inflation, which states that the universe underwent a violent expansion in its first micro-moments. After about 300,000 years it cooled enough to allow the matter to form.

Similar findings

On Friday, a team of European physicists reported similar findings based on new high-precision observations using a radio telescope called the Very Small Array located on the island of Tenerife in the Atlantic Ocean.

The images show the beginnings of the formation of structure in the early universe, according to the researchers from the Universities of Cambridge and Manchester and the Instituto de Astrofisica de Canarias in Tenerife.

The team said that because galaxies must have formed out of the primeval fireball, they should have left imprints in the radiation in the form of tiny variations in temperature.

According to the National Science Foundation, the data collected in Chile is also helping scientists learn more about a repulsive force called "dark energy" that appears to defy gravity and cause the universe to accelerate at an ever-increasing pace.

"Each new image of the early universe refines our model of how it all began. Just as the universe grows and spreads, humankind's knowledge of our own origins continues to expand," commented NSF Director Rita Colwell.

The Science Foundation described the cosmic microwave background as a record of the first photons that escaped from the rapidly cooling, coalescing universe about 300,000 years after the explosion known as the Big Bang that is commonly believed to have given birth to the universe.

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