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Space Science

Dark Matter Discovered Near Solar System? 179

Posted by Soulskill
from the near-being-a-relative-term dept.
gpronger writes "The ATIC (Advanced Thin Ionization Calorimeter) has potentially discovered the presence of dark matter close (only 3000 light-years) to our solar system. The system detected a large-amount of high energy cosmic rays which match the theoretical signature of dark matter annihilating itself. The universe is believed to be composed of about 25% dark matter, but there has been little evidence of it. This discovery, if correct, would be the first." The paper was published in Nature , but it requires a subscription to see beyond the abstract.
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Dark Matter Discovered Near Solar System?

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  • by wideBlueSkies (618979) * on Friday November 21, 2008 @09:11PM (#25854043) Journal

    Dark Matter sees evidence of YOU.

  • zomg (Score:5, Funny)

    by Missing_dc (1074809) on Friday November 21, 2008 @09:11PM (#25854045)

    ZOMG, Mom, is that you?

  • close ? (Score:5, Funny)

    by jacquesm (154384) <jNO@SPAMww.com> on Friday November 21, 2008 @09:21PM (#25854131) Homepage

    This must be some meaning of 'close' that I was previously unaware of.

    • Re: (Score:2, Insightful)

      by gpronger (1142181)
      I was sitting in my office (Chicago) and the phone rang; two vendor reps wanted to drop by, being in the area, but needed some directions. As it happens they were in Peoria (central Illinois) which struck me as peculiar in saying that they were in the area. When they made it in, it turned out they were "in" from Australia. So in fact, from there perspective, they were "in the area".Seems things are all relative.

      All things are relative, all relatives are things, my relatives took all my things.

      Greg
  • We must have very different notions of close. I personally cannot begin to imagine how one could consider 190 million AU to be close.

    • by techno-vampire (666512) on Friday November 21, 2008 @09:31PM (#25854215) Homepage
      Compared to intergalactic space, 3,000 light years is practically next door. It's all relative, and when it comes to astronomy, anything inside the Milky Way is considered close.
      • I believe the size of the universe would be 15 Billion light years - so 3000 is close.

        If my calculations are correct - that would be like finding out that a random person from somewhere on earth - actually lived 27 feet away from you!

        • by ChromaticDragon (1034458) on Friday November 21, 2008 @10:21PM (#25854577)

          Interestingly enough, the universe is almost certainly much bigger than you believe.

          Honestly, we have no idea and probably no real way of determining how big the universe really is. Nonetheless, the observable universe seems to be at least 90 billion light years [wikipedia.org] in diameter. So, it'd be more like finding that random person in the same room.

        • Re: (Score:3, Informative)

          by C18H27NO3 (1282172)
          The current estimation is believed to be ~13.7 billion light years with a diameter of ~93Gly, (46 billion light years in any direction out from Earth).((Comoving distance, cosmologicaql time, et al.)) 3,000 LY would equate to roughly 17,635,876,119,550,800 miles. 46G LY would equate to roughly 270,416,767,166,418,000,000,000 miles.

          While not very close, it is a heck of a lot closer than if we were able to see it nearer the \edge\ of the observable portion of our universe.
        • "...that would be like finding out that a random person from somewhere on earth - actually lived 27 feet away from you!"

          This happened to me - twice! - so I guess the astronomers might have indeed found a lump of dark matter. :-)

    • by ceoyoyo (59147)

      The reason this gets called close is that these are high energy cosmic rays. The high energy ones get slowed down (lose energy) as they zip around the universe, so if we observe them they must originate fairly "close" to us. Close, that is, in comparison to the extra-galactic ones. 3000 light years is nothing, even on a galactic scale.

  • by fred fleenblat (463628) on Friday November 21, 2008 @09:24PM (#25854157) Homepage

    where is the dark antimatter?

  • by east coast (590680) on Friday November 21, 2008 @09:34PM (#25854245)
    The universe is believed to be composed of about 25% dark matter, but there has been little evidence of it. This discovery, if correct, would be the first.

    If this would be the first evidence how can we already have a little evidence of it?
    • by jd (1658) <<moc.oohay> <ta> <kapimi>> on Friday November 21, 2008 @09:53PM (#25854377) Homepage Journal
      It would be more correct to say we lack evidence for viable alternatives, assuming the current models used, for which we now lack evidence unless evidence has been lacking on the existence of dark matter. Which may be great for grant checks, but it's lousy science.
    • by EveLibertine (847955) on Friday November 21, 2008 @09:56PM (#25854391)
      The things that are considered "evidence" of dark matter are things that match prediction models of things that would happen because of dark matter. Fancy stuff like high energy cosmic rays of certain types and the like. The trick is that there are also may be other models that predict similar types of events that are used as evidence of dark matter, but these models are models that exclude the possibility of dark matter

      So, the evidence that points towards dark matter could also point towards other conflicting models of our universe, essentially being evidence for many different models at once. The reason discoveries of this kind of evidence is exciting is because it gives us something to look at and test so that we might select or eliminate from the groups of conflicting models.
      • by NeoSkink (737843) on Saturday November 22, 2008 @12:51AM (#25855425)
        No other theory works as well as dark matter (as part of LCDM) to explain obersavations. Other theories have to be changed to account for what we observe at pretty much every scale. Those that work for Galaxy rotation don't work for clusters, which don't work for lensing, which don't work for early structure formation, and so on. Sure, one or two pieces of evidence may favor one theory or another over dark matter, but LCDM fits in the vast majority of cases, far more than any other theory.

        Heck, you don't think that we scientists got together one day and said "I know, lets make up some goofy theory and then fudge the data to fit it!" do you? You do realize multiple theories were purposed, predictions were created, new data was taken, and conclusions drawn about which theories were supported by the new evidence, right? And that LCDM is the one that survived all the vetting? And that this process is still on going, yet LCDM still remains as the best theory?

        Just checking... See, that's sort of how science is supposed (and in this case does) work.
        • by JLF65 (888379)

          Heck, you don't think that we scientists got together one day and said "I know, lets make up some goofy theory and then fudge the data to fit it!" do you?

          Actually, it's the other way around. Scientists looked at the data and saw it didn't fit, so they made up some goofy theories that "explained" why their calculations didn't match reality.

          No! My theory isn't WRONG! It's ... err... invisible matter that can't be detected in any manner!! Yeah! That's the ticket!

          Can you imagine if you did that in any other fie

          • Re: (Score:3, Interesting)

            by Anonymous Coward

            Actually, it's the other way around. Scientists looked at the data and saw it didn't fit, so they made up some goofy theories that "explained" why their calculations didn't match reality.

            OK, so scientists look at how galaxies behave and notice that they are behaving as if they had more mass than we can observe them having. Now there are two options: either 1. galaxies contain mass that hasn't been observed or 2. the theories of how the gravity works need to be revised. Both of these options are being studie

          • Re: (Score:3, Interesting)

            by Ambitwistor (1041236)

            Scientists looked at the data and saw it didn't fit, so they made up some goofy theories that "explained" why their calculations didn't match reality.

            Yeah, uh, DUH. That's what science IS. You make up a theory to describe what you observe. If it doesn't fit, it's wrong, so you make up a new one and see if that works.

            As another poster said, you seem to have some kind of ideological prejudice against the particular theory they came up with. But it's foolish to criticize them merely for coming up with a new theory in the first place. That's what they're SUPPOSED to do.

            No! My theory isn't WRONG! It's ... err... invisible matter that can't be detected in any manner!! Yeah! That's the ticket!

            So you're mocking the idea that there can be particles out there which don't interact

          • Scientific theories about thing in normal world scales tend to be pretty comfortable psychologically, move into cosmological or quantum scales and things can get goofy real quick, I suspect that truly understanding Quantum Mechanics is a sign of psychosis.

      • by aliquis (678370)

        Ohnoez, science goes the way of religion =P

        Can we please keep the evidence as evidence and don't count theoretic results of theoretic theories as somewhat less trustworthy evidence? :D

        • Sheesh. Grow a clue.

          "The theory passes numerous observational tests" != "ZOMG science is religion!!1!!".

    • There is a huge amount of numbers between zero and one. Duhh.
    • by Goaway (82658)

      We don't have "a little" evidence, we have "little" evidence. These are two distinct concepts in English. Just "little" is usually understood to contain "no" as possible value.

    • Perhaps English is not your first language, but "I have little sympathy for fools and Republicans" means that I have no sympathy for them. "I have a little money" means I do have some money, just not a lot.

      (Incidentally, there's plenty of evidence for dark matter.)

  • Bad summary. (Score:5, Informative)

    by JohnnyDanger (680986) on Friday November 21, 2008 @10:05PM (#25854461)

    The summary misinterprets the results.

    The instrument detects high-energy electrons. They found an excess (only 70, but statistically significant) with a particular energy, which if they come from a galactic source (like a pulsar), that source must be within 3000 light years. However, the researchers can't find an appropriate source.

    Alternatively, this could be due to annihilating dark matter---the energy spectrum matches some models---but that's not necessarily coming from a particular source.

  • I still believe that 'dark matter' is only a temporary constant inserted into an equation modern scientists don't truly understand.

    In time they will discover what is causing the effects of this 'dark matter' - it will not be super strange matter, nor another form of matter, but will be either a change in the overall calculations of our universe's energy or it will be some type of substance that was not accounted for.

    Theorists throw in some offbeat number to the calculation every 30 years or so to account f

    • Re: (Score:3, Interesting)

      by rrohbeck (944847)

      Well *something* is warping spacetime this way and that, and that's what they call dark matter and dark energy respectively. Now the question is what does the warping.

    • by S3D (745318)
      You probably mistake dark energy [wikipedia.org] for dark matter [wikipedia.org]. Dark energy is indeed most probably a cosmological constant [wikipedia.org] and related to the energy of universe. Dark matter is completely different thing - it's an invisible mass causing anomalous speed distribution of the galaxies in the clusters, stars in the galaxies and most spectacular - shape of the Bullet Cluster [wikipedia.org]
    • In time they will discover what is causing the effects of this 'dark matter' - it will not be super strange matter, nor another form of matter, but will be either a change in the overall calculations of our universe's energy

      "Calculations of our universe's energy" don't have anything to do with the fact that gravitational orbits don't look right. There are basically only two posibilities: there is an unseen source of gravity, or gravity doesn't work the way we think. Both options have been explored, and the first agrees best with all the data.

      or it will be some type of substance that was not accounted for.

      You mean some unknown substance which we haven't been able to see, but which affects orbits ... like, I don't know, "dark matter"?

      There are already strong constraints on what kind of su

      • It's not ordinary baryonic matter (made of protons and neutrons) at all; that would have completely altered the ratio of elements created in the Big Bang to something we don't observe.

        Thanks, your post answered several of my questions.
        If you have the time, could you explain a bit more about this ratio? What implications would it have if dark matter consisted of baryonic matter? Honest question, I simply don't know :)

        • This is how I recall it: if dark matter was baryonic, then the early universe would have produced a lot more helium and less deuterium. Deuterium has 1 proton and 2 neutrons; helium has 2 protons and 2 neutrons. If there are a lot of extra baryons (protons and neutrons) around, it's easy for them to collide with existing deuterium atoms and produce helium. I think ...

          Also, if there are a lot of baryons around, I think the early universe doesn't "clump" enough to produce the superclusters and things we s

  • Big deal. I find dark matter every time I turn out the lights.

    This is science?

  • The universe is believed to be composed of about 25% dark matter, but there has been little evidence of it. This discovery, if correct, would be the first.

    No it would be evidence of "a large amount of high energy cosmic rays".

  • by DreadPiratePizz (803402) on Saturday November 22, 2008 @02:06AM (#25855765)
    It's in my massive muscular physique! [meatheadmania.com]
  • meh... come back and wake me up when it gets to 300 light years...

    on a secondary note, I wonder if the solar system has passed through several "clouds" of this stuff during its lifetime? Could explain major die-offs on Earth...

  • Everyone knows very well that dark matter alone is to blame [arxiv.org] when we face inflation [wikipedia.org], and printing presses [wikipedia.org] are totally innocent.

Theory is gray, but the golden tree of life is green. -- Goethe

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