Physicists are closer to understanding how ultrahigh-energy cosmic rays make their way to Earth thanks to new measurements made at the Pierre Auger Observatory in Argentina. The study shows that the number of such cosmic rays reaching Earth drops off rapidly for rays with energies of more than about 4 x 10^19 eV.
The observations are consistent with a 40-year-old theory that ultrahigh-energy cosmic rays cannot travel very far through the universe without losing energy as they scatter off the cosmic microwave background.
4 x 10^19 eV... hum.. quick! How many orders of magnitude is that higher than the highest energy the LHC can ever reach?! And people are rabidly worried about the LHC creating blackholes?