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GZK cutoff confirmed by Auger
http://sciencenow.sciencemag.org/cgi/content/full/2007/703/1
If cosmic rays are mostly highly-accelerated protons, then
above a certain energy they should react with the pervasive photons of the CMB
and get wiped out.
this is known as the GZK (Greisen, Zatsepin and Kuzmin) cutoff
In other words, space (being full of CMB photons) should not be transparent to any proton that is above about 1018 eV.
And we should see comparatively little cosmic rays above that energy.
there was some doubt about this. But Auger confirmed it.
the blog Backreaction, which should be a household word by now, has discussion and more links
http://backreaction.blogspot.com/2007/07/gzk-cutoff-confirmed.html
http://sciencenow.sciencemag.org/cgi/content/full/2007/703/1
If cosmic rays are mostly highly-accelerated protons, then
above a certain energy they should react with the pervasive photons of the CMB
and get wiped out.
this is known as the GZK (Greisen, Zatsepin and Kuzmin) cutoff
In other words, space (being full of CMB photons) should not be transparent to any proton that is above about 1018 eV.
And we should see comparatively little cosmic rays above that energy.
there was some doubt about this. But Auger confirmed it.
the blog Backreaction, which should be a household word by now, has discussion and more links
http://backreaction.blogspot.com/2007/07/gzk-cutoff-confirmed.html
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