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Re: Of Cosmic Rays and Dangerous Days



The full article is available for free:

Mikhail V. Medvedev, Adrian L. Melott 2007. "Do extragalactic cosmic rays induce cycles in fossil diversity?" Astrophysics 664: 879-889

http://arxiv.org/abs/astro-ph/0602092
http://arxiv.org/PS_cache/astro-ph/pdf/0602/0602092v3.pdf



Dann Pigdon writes:


Of Cosmic Rays and Dangerous Days
By Phil Berardelli
ScienceNOW Daily News, 1 August 2007


Researchers may have uncovered the reason why Earth's biodiversity mysteriously plummets periodically. They have found that a rollercoaster-like wobble in the sun's orbit around the center of the Milky Way galaxy regularly moves Earth closer to a source of dangerous intergalactic cosmic rays.

Over the last 500 million years or so, the number of species on Earth has tended to dip regularly about every 62 million years. The last time this happened, about 55 million years ago--or about 10 million years after the great K-T extinction event that wiped out the dinosaurs--biodiversity sank by about 10%; around 115 million years ago, it dropped by a similar amount. So far, evolutionary biologists have only been able to establish that the phenomenon seems cyclical, but they haven't isolated a cause.

Now, researchers from the University of Kansas in Lawrence think they have found a possible answer...

Read more at:

http://sciencenow.sciencemag.org/cgi/content/full/2007/801/1

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Dann Pigdon
GIS / Archaeologist              geo cities.com/dannsdinosaurs
Melbourne, Australia             heretichides.soffiles.com
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