By Ron Cowen
Intrepid explorers braved the unknown to find that the world is round. Now, a detector suspended from a balloon circling the frigid Antarctic has measured the curvature of the universe and revealed that it’s perfectly flat.
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The balloon-borne experiment detected tiny fluctuations in the temperature of the cosmic microwave background, the whisper of radiation left over from the Big Bang. This energetic radiation cooled to microwave energies as it traveled through space for some 13 billion years.
The new data, from the Italian-U.S. experiment BOOMERANG (Balloon Observations of Millimetric Extragalactic Radiation and Geophysics), represent the most detailed images ever taken of the infant universe, says Andrew E. Lange of the California Institute of Technology in Pasadena.