Researchers with an experiment based at the South Pole have discovered the long-sought "smoking gun" for inflation. The signal was hidden in polarization patterns in the cosmic microwave background and confirms physicists' audacious theory of how the Big Bang happened.
Planck mission scientists have released the first half of their observations of the cosmic microwave background. The results are a stunning confirmation of today's standard model for how the universe formed and grew. But they also raise some head-scratchers.