Cold spot could be relic of Big Bang - scientists

CHICAGO, Oct 26 (Reuters) A cold spot in the oldest radiation in the universe could be the first sign of a cosmic glitch that might have originated shortly after the Big Bang, British and Spanish scientists said.

They think this spot -- detected on satellite maps of microwave radiation -- might be a cosmic defect or texture, a holdover from the universe's infancy. But they said their theory would need confirmation.

Such defects or textures, they theorize, reflect a flaw in the pattern of the universe as it formed -- think of a snag in pantyhose or a flaw in a diamond.

''If the cold spot is indeed proven to be a texture, it will completely change our view of how the universe evolved following the Big Bang,'' said Mike Hobson, of the Astrophysics Group at the University of Cambridge's Cavendish Laboratory yesterday, whose study appears in the journal Science.

Hobson, Neil Turok and colleagues at the Institute of Physics at Cantabria based this theory on an analysis of a large cold spot in the cosmic microwave background radiation, which is basically the heat glow left over from the formation of the universe.

The cold spot was discovered in 2003 by NASA's Wilkinson Microwave Anisotropy Probe satellite, and its presence has been the subject of many theories, said Al Kogut of the NASA Goddard Space Flight Center.

Kogut, who did not work on the paper, said if this texture theory is proven, it would offer a window into the universe shortly after the Big Bang some 14 billion years ago, showing places where the universe was expanding and cooling.

''If you imagine water cooling down in an ice cube tray, it will make a transition from a liquid state to solid crystal,'' Kogut said in a telephone interview.

If that occurs very slowly, he said, that transition goes very smoothly, producing crystal clear ice. But if it goes very fast, the crystal aligns in different directions. Where they don't agree, a crack appears, he said.

This paper ''is basically saying this cold spot is a relic of high-energy physics that occurred immediately after the Big Bang,'' Kogut said.

''They're claiming they've found one of these things and it could be the tip of the iceberg,'' he said.

But Kogut, like the study's authors, said he would like more proof. ''The evidence is encouraging, but far from compelling,'' he said.

REUTERS ARB KN0846