Astronomers hunt for the universe's oldest light

A pattern of light twisted during a journey of billions of years from the very early universe, has been detected for the first time, astronomers say. During its long travel to Earth, the ancient light was distorted by the pull of matter, leading to a twisted light pattern called B-modes that astronomers have been able to detect using the National Science Foundation's South Pole Telescope and the Herschel space observatory, NASA's Jet Propulsion Laboratory in Pasadena, Calif., reported Tuesday. Two types of B-modes have been predicted by scientists. The ones recently found were generated a few billion years into the universe's 13.8-billion-year existence. The others, called primordial, are theorized to have been produced when the universe was newly formed, fractions of a second after the big bang. "This latest discovery is a good checkpoint on our way to the measurement of primordial B-modes," said Duncan Hanson, of McGill University in Montreal and lead author of the report published in Physical Review Letters. Scientists say the primordial B-modes, if they can be detected, may be imprinted with clues about how the universe was born. "These beautiful measurements from the South Pole Telescope and Herschel strengthen our confidence in our current model of the universe," JPL scientist Olivier Dore said. "However, this model does not tell us how big the primordial signal itself should be," he said. "We are thus really exploring with excitement a new territory here and a potentially very, very old one."