April 18, 2012
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. /University of Wisconsin-Madison
Read more >> http://www.news.wisc.edu/20577
What are cosmic rays?
Galactic cosmic rays (GCRs) are the high-energy particles that flow into our solar system from far away in the Galaxy. GCRs are mostly pieces of atoms: protons, electrons, and atomic nuclei which have had all of the surrounding electrons stripped during their high-speed (almost the speed of light) passage through the Galaxy. Cosmic rays provide one of our few direct samples of matter from outside the solar system. The magnetic fields of the Galaxy, the solar system, and the Earth have scrambled the flight paths of these particles so much that we can no longer point back to their sources in the Galaxy. If you made a map of the sky with cosmic ray intensities, it would be completely uniform. So we have to determine where cosmic rays come from by indirect means.
Se också Ny Tekniks artikel om upptäckaren av kosmisk strålning (upptäkten gav Nobelpris) >> http://www.nyteknik.se/popular_teknik/kaianders/article3418903.ece
