|
|
 |
|
|
Physicists confirm 42-year-old theory
SALT LAKE CITY, March 25 (UPI) -- A U.S. study has confirmed a 1966 prediction that the most energetic cosmic ray particles in the universe aren't from our solar system
The University of Utah's cosmic ray observatory confirmed most cosmic rays in the universe rarely reach Earth at full strength because most of them collide with radiation left over from the birth of the universe.
The findings confirm a 42-year-old prediction about the behavior of ultrahigh-energy cosmic rays, which carry more energy than any other known particle.
The theory posits most cosmic ray particles cannot reach Earth because they lose energy when they collide with cosmic microwave background radiation from the "big bang" that's believed to have formed the universe 13 billion years ago.
"It has been the goal of much of ultrahigh-energy cosmic ray physics for the past 40 years to find this cutoff or disprove it," said University of Utah physics Professor Pierre Sokolsky. "For the first time in 40 years, that question is answered: there is a cutoff."
The research appears in the journal Physical Review Letters.
Copyright 2008 by United Press International
|
|
| |
|
|
|
|
