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"Blue Light Special" -- The Discovery Files

The Discovery Files
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Analysis of data from the IceCube Neutrino Observatory, a massive detector deployed in deep ice at the U.S. Amundsen-Scott South Pole Station in Antarctica, provided insight into one of the most enduring mysteries in physics, the production of cosmic rays.

Credit: NSF/Karson Productions

Audio Transcript:

It's Like, Cosmic

I'm Bob Karson with the discovery files--new advances in science and engineering from the National Science Foundation.

For over a century scientists have known of the existence of cosmic rays--electrically-charged particles that strike the earth from all directions. What remains a mystery is where they come from. Two theories seemed most plausible, one: Cosmic rays could originate from black holes at the center of massive galaxies or two: From exploding fireballs in space (Sound effect: space explosion) called gamma ray bursts. New observations from the IceCube Neutrino Observatory at the South Pole say of the second theory: Mmmm, maybe not.

Physicists believe neutrinos accompany cosmic ray production. They searched for the presence of neutrinos emitted from 300 gamma ray bursts observed over two years. They found no neutrinos--contradicting 15 years of predictions. So while we still don't know where cosmic rays come from, we now have evidence that may indicate where they don't originate.

(Sound effect: Antarctic winds) The IceCube Observatory is one kilometer of solid glacial ice fitted with more than 5,000 optical sensors embedded up to two and a half kilometers. It detects neutrinos by the faint blue light emitted when neutrinos pass through and interact with the ice. Scientists will continue to explore the cosmic ray mystery, so the results of this neutrino search may just be the 'tip of the ice cube'.

"The discovery files" covers projects funded by the government's national science foundation. Federally sponsored research--brought to you, by you! Learn more at or on our podcast.

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