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Origin of Cosmic Rays Confirmed

Posted by kdawson on Sun Oct 28, 2007 04:14 PM
from the just-as-we-suspected dept.
Space Science
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.
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Submission: Origin of cosmic rays explained ? by cats-paw (34890)
[+] Cosmic Rays From Galactic Black Holes 51 comments
dork writes in with word of a study that contradicts, at least for the highest-energy events, the recent conclusion that cosmic rays are probably formed in supernova remnants. The Pierre Auger Observatory in Argentina has announced that active galactic nuclei are the most likely candidates for the source of the highest-energy cosmic rays that hit Earth. The researchers found that the sources of these highly energetic events are not distributed uniformly across the sky, linking their origins to the locations of nearby galaxies hosting active nuclei in their centers. These galaxies are thought to be powered by supermassive black holes that are devouring large amounts of matter. The exact mechanism of how particles get accelerated to energies 100 million times higher than achievable by the most powerful particle accelerators on Earth is still unknown. The observatory has made 1% of its events available through a public online event display."
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  • Synopsis (Score:3, Funny)

    by Anonymous Coward on Sunday October 28 2007, @04:18PM (#21150951)
    The Cosmos

  • d'oh (Score:5, Funny)

    by User 956 (568564) on Sunday October 28 2007, @04:21PM (#21150977) Homepage
    research that seems to confirm and support current theories of how cosmic rays are created.

    Oh, great, now that everyone knows how to make them, the Fantastic Four are going to be up to their eyeballs in supervillainry.

  • When I punch 10^15 eV into Google... (Score:3, Funny)

    by nexuspal (720736) on Sunday October 28 2007, @04:22PM (#21150985)
    It comes back with .00160217 joules. Isn't this a very small amount of energy, or am I missing something?

    • Re:When I punch 10^15 eV into Google... (Score:5, Informative)

      by the_brobdingnagian (917699) on Sunday October 28 2007, @04:24PM (#21151005) Homepage
      Not if that's the energy of a single proton.

      • Re:When I punch 10^15 eV into Google... (Score:5, Informative)

        by Bonker (243350) on Sunday October 28 2007, @04:49PM (#21151183)
        For Comparison [wikipedia.org]

        * 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.

        • Re: (Score:3, Informative)

          by geekboy642 (799087)
          Those numbers are 3.2x10^-11 and 3.5x10^-11 respectively. Formatting is a bitch. Guess that's why they invented "Preview", eh Paco?

          • Re:When I punch 10^15 eV into Google... (Score:4, Informative)

            by Bonker (243350) on Sunday October 28 2007, @08:03PM (#21152621)
            While the above poster is obviously in jest, it's worth pointing out the difficulties with his suggestion.

            The only way we currently have of energizing protons to even a measurable fraction of energy like this is in particle accelerators. They're spun around in magnetic fields to faster and faster speeds, gaining mass and energy or energy as they go. That energy ultimately comes from some kind of generator and the fuel it uses.

            Eventually, they're slammed into a stationary target or a particle going the other way in the same accelerator. The more mass and energy the particles have accumulated, the more exotic the reactions that occur when that happens. The point of the experiment is to funnel a massive amount of fuel energy into one spot and see what happens when it goes 'boom'.

            The super-energetic cosmic rays use the magnetic shockwave created by a Supernova to achieve about the same effect. Rather than being spun around a particle accelerator, they're being spun around the coiled loops of magnetic flux created when a super-massive star decides to disembowel itself.

            So, to get anywhere near the ability to create one of these, let alone some kind of ray weapon utilizing them, we'd need a particle accelerator larger than the Sun (or able to churn out more energy than the Sun does). By the time we were able to build one, we'd be dismantling planets by other means anyway.
      • That is a lot of energy for one proton, but not compared to the highest energy cosmic rays that have been observed. Those pack almost 10^21 eV (about the energy of a pitched baseball) into a single particle.

        • Re:When I punch 10^15 eV into Google... (Score:5, Informative)

          by MoxFulder (159829) on Sunday October 28 2007, @07:07PM (#21152235) Homepage
          Indeed. The wikipedia article on ultra-high-energy cosmic rays [wikipedia.org] has more info. The energy of such a particle is simply insane...

          Some of them apparently violate a theoretical limit on the energy of a particle that has traveled a long way across the universe... leading to the question of where exactly they come from.
          • No shit. Quoting wikipedia:

            The Oh-My-God particle (a play on the nickname "God particle" for the Higgs boson) is the nickname given to a particle observed on the evening of October 15, 1991, over Dugway Proving Grounds, Utah, estimated to have an energy of approximately 3 × 10**20 electronvolts, equivalent to about 50 joules

            50 joule proton... Almost makes you suspect the gods made a mistake with their pointer arithmetic. Either that or someone crossed the streams.

    • 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

    • Re: (Score:3, Interesting)

      by viking80 (697716)
      Multiply that with Avogadro's number, and you get the energy of a regular bullet with 'cosmic ray' speed:
      6x10^20 J. That, amazingly, equals the total enery production on earth in one year. http://en.wikipedia.org/wiki/World_energy_resources_and_consumption [wikipedia.org]

    • Re:When I punch 10^15 eV into Google... (Score:5, Informative)

      by Omnifarious (11933) * on Sunday October 28 2007, @05:49PM (#21151683) Homepage Journal

      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.

    • That's the energy per particle (proton). Its quite a bit for such an itsy-bitsy (sorry for the technical jargon) thing.

    • It comes back with .00160217 joules. Isn't this a very small amount of energy, or am I missing something?
      And it's in a proton about .0000000000000000000000000000000000000000000007m^3 big.
    • If you had a kilo of that stuff, it'd be enough to power the world's energy consumption for the next 200 years. I think that's as close as you get to a layman's understanding of how much power that is.
    • BTW, the current record [wikipedia.org] for a cosmic ray (most likely a single proton) was estimated to have the kinetic energy of a thrown baseball. But it weighed 26 orders of magnitude less (assuming it was a proton).

  • [OT] Nitpicking summary (Score:4, Insightful)

    by noidentity (188756) on Sunday October 28 2007, @04:24PM (#21151001)

    [...] news of research that seems to confirm and support current theories of how cosmic rays are created. [...] 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.

    So this research confirms... supports...well lends support to the possibility. Care to soften it further?

    • Re: (Score:2, Informative)

      by Anonymous Coward
      The wording in the summary is a good representation of the article. The work confirms the origins of cosmic rays in supernova remnants and lend support to the idea that they can reach energies of 1 PeV, which is energy in excess of what has been theorized as being possible. In other words, a new upper limit. They are two separate and accurate statements.
      • Why is there an upper limit to how fast you can accelerate a proton? I mean in energy, as it approaches c, does something bad happen as it reaches that threshold? Relativistics was never my forte.

        • Re: (Score:3, Interesting)

          by ResidntGeek (772730)
          I believe it's an upper limit to how fast this particular mechanism can accelerate a proton, not how fast a proton can be accelerated under any circumstances.

        • Re: (Score:2, Interesting)

          by Scott Carnahan (587472)
          Can you propose a mechanism for star formation that would give the sun a sufficiently large positive charge to accelerate ions at large distances? That voltage difference had to come from somewhere, and large charge imbalances counteract the gravitational attraction needed for nuclear fusion.

          Maybe I'm wasting my time. It seems clear that "alternative cosmologies" means the electric universe theory, which doesn't make any useful, testable predictions.

  • they are created when God puts foil in his microwave :P
    • You joke -- obviously God doesn't need a microwave when he can simply will his food to be cooked -- but in all seriousness, they come from his X-Ray vision.
      • You joke -- obviously God doesn't need a microwave when he can simply will his food to be cooked -- but in all seriousness, they come from his X-Ray vision.

        Well that's almost true. Actually he sub contracts the job to Chuck Norris.
      • Not to be a sticker, but Kansas *was* the state with the retarded school board. We voted out those idiots.

  • a good science post? (Score:5, Insightful)

    by Goldsmith (561202) on Sunday October 28 2007, @04:43PM (#21151143)
    Give credit to cats-paw for giving us the link to the abstract for the original paper and to the editors for putting this up rather than a link to some half-baked pseudo-science blog about it.

    I think if I was not an experimentalist, I would want to study this area of physics (supernova observation). Going through the steps of a supernova exposes you to some of the most amazing physics we know of, and this research only adds to that.

  • nuclei, NOT nucleii (Score:5, Informative)

    by Anonymous Coward on Sunday October 28 2007, @04:43PM (#21151149)
    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")

    • Stop trying to sound "smart" by ending words with "ii".
      Isn't it more likely that it was a simple error?

    • "nucleus" -> "nuclei"

      For George Bush it's "nuculi", though "nuculei" sounds cooler.
  • Converting from eV to fahrenheit gives that these interactions are taking place at: 6,446,700,000,000,000,000 degrees! That's 6.4 billion billion degrees.
  • I think "Cosmic Ray's" would be a great name for a futuristic bar. That, or the "Space Bar".
  • ... they are shrapnel from some distant intergalactic war.
  • First of all, the summary (but also the article) refer to "cosmic rays", as if they are all the same. Most, actually, come from the sun. The nature abstract talks about "galactic cosmic rays", which better, but there are thought to be many flavors of these as well, as there are many ways to accelerate charged partcles.

    The poster child of uber-freaked out cosmic rays is a crazy bugger [wikipedia.org] detected in 1991 that had an energy of 3.2 x 10^20 eV. One scientist compared it to dropping a brick on your toe! Cosmic r

    • Re: (Score:3, Informative)

      by hubie (108345)

      Most, actually, come from the sun.

      Maybe at 1AU, but out beyond the magnetosphere that isn't true.

      For what it's worth, the many flavors of galactic cosmic rays you mention is pretty much the periodic table. While true there are a variety of ways to accelerate a charged particle, there are not that many known ways to get them to those energies that don't stick out like sore thumbs (which is why supernovae were always the best candidates). For the galactic cosmic rays, at least one of the methods must

    • Yet again, another armchair commenter wants to clarify what Science Is. Summary says:

      ... seems to confirm and support current theories... The results lend support to the possibility of protons and nucleii being accelerated...

      Additionally, the abstract says their research "provide[s] a strong argument" for a theory. I suppose these statements are way too hard-line for Real Science. Sheesh. These are people who know very well they're doing inference rather than deduction - including the submitter! - and you take them to task for jumping to conclusions.

      You say:

      ... yet another phenomenon which does not demonstrate the prominent possibility to be incorrect. It seems a minor distinction, but it's important to science that science can't "prove" anything - only attempt to disprove by null hypothesis.

      The hypothesize/predict/experiment cycle isn't nearly as boolean as you make it out, even though we teach it that way in school.

      If a result doesn't disprove a theory, it actually increases its probability among other possibilities. Bayesian statistics models this quite well, and scientists think about it that way but without such a rigorous foundation. For example, in all forces, we've measured the differential relationships among position, velocity and acceleration to ridiculous precision. Doesn't this increase the probability that we've got it right? In this area, if there's a conflict between predicted and expected outcomes, we regard the explanation that the theory is wrong as the less probable one - much less probable.

      Part of the problem is classical statistics. Null hypotheses and tests against them are kludgy nonsense, everyone knows it, and everyone has their own way of doing it "properly". (Think about it this way: Pr(null hypothesis), where the null hypothesis has a continuous component - and this is done all the time - is ZERO.) Doing inference without priors is a misguided attempt at objectivity. These mindsets are well-preserved in scientific philosophy, and they've got to go. Nobody actually thinks about real inference the classical way. It'd be ridiculous to try it on any hypothesis of moderate complexity.

    • Re: (Score:2, Funny)

      by Anonymous Coward
      No No No No No
      No No No No No No No
      No No No... Maybe

    • Benjamin Jacob Grimm says "Wear your lead lined skivvies if your going into space, kids"

      Of course, at this energy the impact of the proton with the lead would result in a lot of neutrons being released, and lead doesn't stop those very well. Maybe if you made some sort of composite-sandwich with lead followed by neutron moderating material and a neutron absorber. Of course, then the neutron-activation of the absorber would cause gamma-ray emissions, so you'd need another layer of lead, possibly followed by

    • Re: (Score:3, Informative)

      by habig (12787)
      Interestingly, there's about the same energy density in a cc of space from cosmic rays as there is from starlight. The difference is that photons travel straight so you see the stars as points of light, cosmic rays get all scrambled from the magnetic field so things would appear hazy.

      But Olber's paradox says that if the universe were infinitely large and infinitely old, then no matter where you looked you'd eventually see the surface of a star, so the sky wouldn't just be bright: it would be be sun-bright,

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