A new scientific discovery about cosmic rays, by an international team of physicists including researchers at Cave Hill campus, has sparked hope locally that such high profile experiments may pique students’ interest and give impetus to the level of scientific enrolment at the University of the West Indies.
Although cosmic rays were discovered 100 years ago, their origin remains one of the most enduring mysteries in physics. New evidence, however, rules out gamma-ray bursts as sources of these ultra-high-energy cosmic rays – electrically charged subatomic particles that reach Earth from deep in outer space. They strike Earth from all directions, with energies up to one hundred million times higher than those created in man-made accelerators.
Cave Hill’s involvement in the discovery coincides with the campus’ preparations to rebrand its natural sciences faculty as the Faculty of Science and Technology from academic year 2012/13. The renaming is among several initiatives being undertaken to emphasise a strategic repositioning of the university’s principal academic focus.
The scientific discovery was made by IceCube Neutrino Osbservatory, a massive detector in Antartica, operated by a collaboration of 250 physicists and engineers from Australia, Barbados, Belgium, Canada, Germany, Japan, New Zealand , Sweden, Switzerland and the USA. Their findings contradict 15 years of predictions and challenge one of the two leading theories for the origin of the highest energy cosmic rays. A study of the findings is published in the current issue of the journal Nature.
Dr. Surujhdeo Seunarine who spearheads the IceCube effort at UWI, Cave Hill, believes the discovery could be a catalyst for increased student interest in science.
He said: “Neutrinos are tiny, electrically neutral particles. We believe they are one of the fundamental particles of nature. They are so hard to observe that they are sometimes described as ‘ghostlike’. But the IceCube detector is sensitive enough to observe them. Given the predictions made by theoretical models of Gamma Ray Bursts, we were expecting to see some neutrinos. This is a case where one gets excited about seeing nothing, because it means we have to go back to the drawing board to try to understand how GRBs and cosmic rays are related. We hope our students in Barbados will get excited about this type of science. They certainly have an opportunity to work on a very high profile experiment while studying in Barbados.”
IceCube spokesperson and University of Maryland physics professor Greg Sullivan noted: “The result of this neutrino search is significant because for the first time we have an instrument with sufficient sensitivity to open a new window on cosmic ray production and the interior processes of GRBs.
“The unexpected absence of neutrinos from GRBs has forced a re-evaluation of the theory for production of cosmic rays and neutrinos in a GRB fireball and possibly the theory that high energy cosmic rays are generated in fireballs.”
GRBs, the universe’s most powerful explosions, are usually first observed by satellites using X-rays and/or gamma rays. GRBs are seen about once per day, and are so bright that they can be seen from half way across the visible Universe. The explosions usually last only a few seconds, and during this brief time they can outshine everything else in the universe.
“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.
Improved theoretical understanding and more data from the compete IceCube detector will help scientists better understand the mystery of cosmic ray production. IceCube is currently collecting more data with the finalized, better calibrated, and better understood detector.
For more information about IceCube, visit www.icecube.wisc.edu.