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Origin of Cosmic Rays Confirmed

Posted by kdawson on from the just-as-we-suspected dept.

cats-paw writes in with news of research that seems to confirm and support current theories of how cosmic rays are created. The prevailing thinking has been that cosmic rays are generated in the regions where supernovas' shock waves interact with the interstellar medium. The new research used the variability in X-ray emissions from a supernova remnant to estimate the strength of the magnetic fields present in that environment. The results lend support to the possibility of protons and nucleii being accelerated in supernova remnants to energies of 1 PeV (10^15 eV) and beyond. Here is the abstract from Nature.

7 of 155 comments (clear)

  1. Re:When I punch 10^15 eV into Google... by the_brobdingnagian · · Score: 5, Informative

    Not if that's the energy of a single proton.

  2. According to the creation museum in Kansas by antifoidulus · · Score: 5, Funny

    they are created when God puts foil in his microwave :P

    --
    Monstar L
  3. Re:When I punch 10^15 eV into Google... by nukeade · · Score: 5, Informative

    It is, but it's all in one tiny particle (often a relativistic nucleus with all of its electrons stripped away). The energy density, then, is truly outrageous.

    ~Ben

  4. nuclei, NOT nucleii by Anonymous Coward · · Score: 5, Informative

    Stop trying to sound "smart" by ending words with "ii". To make Latin words ending "us" plural, remove the "us" and add ONLY ONE "i".

    "nucleus" -> "nuclei"

    "radius" -> "radii" (because there's already an "i" before the "us")

  5. Re:When I punch 10^15 eV into Google... by Bonker · · Score: 5, Informative
    For Comparison

    * 3.2×1011 joule or 200 MeV - total energy released in nuclear fission of one U-235 atom (on average; depends on the precise break up)
    * 3.5×1011 joule or 210 MeV - total energy released in fission of one Pu-239 atom (also on average)


    So, imagine the energy level to be 8-9 ORDERS OF MAGNITUDE (or around a billion times) more energetic than a nuclear fission chain reaction.
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  6. Re:When I punch 10^15 eV into Google... by Omnifarious · · Score: 5, Informative

    So, it takes 4.1868 joules to heat one cubic centimeter of water (one gram of water) one degree centigrade. So 0.00160217 joules is enough to heat one gram of water 383 microdegrees.

    So, yes, in one sense that's not very much energy.

    But, if you're going to scale the mass up, you should scale the energy up. So, it's one proton that has that much energy. The gram of water has approximately 6.02*10^23 proton masses. If every proton mass in the gram of water had that much energy, it would be equivalent to that gram of water being heated by 2.3*10^20 degrees. This is 230 trillion trillion degrees (yes, that's two trillions).

    I hope this gives you a sense of the scale involved here.

    When you have a single proton with enough energy to make a measurable difference in the temperature of a gram of water, you are talking an amazingly huge amount of energy.

    --
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  7. Re:Very, very hot by White+Flame · · Score: 5, Funny

    6,446,700,000,000,000,000 degrees! That's 6.4 billion billion degrees.

    But how many Libraries Of Congress On Fire is that?