The supergiant black hole Sgr A* at the milky way center... or something near it... apparently emits very high energy cosmic rays! "Somewhere within the central 33 light years of the Milky Way there is an astrophysical source capable of accelerating protons to energies of about one petaelectronvolt, continuously for at least 1000 years" -- Emmanuel Moulin (CEA, Saclay). Acceleration of petaelectronvolt protons in the Galactic Centre, Nature, 2016 http://www.nature.com/nature/journal/vaop/ncurrent/full/nature17147.html see also http://arxiv.org/abs/1509.03425 http://www2.cnrs.fr/en/2727.htm I suppose what must happen is stuff falling into the hole collides with other stuff at extremely near light speed, emitting the rays as a result? If that is the explanation, then the speeds involved need to be so high that the kinetic energy of the collidors are a factor>10^6 times their rest masses. But would that even work? Wouldn't such rays be gravitationally red shifted so that we out here would not perceive them as ultrahigh energy -- and this could only produce run of the mill energies of order 1 GeV? So it is very hard to explain how such enormous cosmic ray energies could be produced, but at least they now have realized a fairly small source near the galaxy center can and does create them. Hmm. Here is a crazy idea. Dark matter particles fall into the hole & collide, emitting the rays as before. But hypothesize the DM particles each outmass protons by a factor 10^6. That would do the job. The highest energy accelerator on Earth, the LHC, just achieved 6.5 TeV beam energy, which is 6.5*10^12 eV, last year. -- Warren D. Smith http://RangeVoting.org <-- add your endorsement (by clicking "endorse" as 1st step)