MADISON – Although cosmic rays were discovered 100 years ago, their origin remains one of the most enduring mysteries in physics. Now, the IceCube Neutrino Observatory, a massive detector in Antarctica, is honing in on how the highest energy cosmic rays are produced.
"Although we have not discovered where cosmic rays come from, we have taken a major step towards ruling out one of the leading predictions," said IceCube principal investigator and University of Wisconsin–Madison physics professor Francis Halzen.