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Physicists Identify Possible New Particle Behind Dark Matter 103

Posted by Soulskill from the it-was-a-frame-job-the-whole-time dept.
sciencehabit writes: Like cops tracking the wrong person, physicists seeking to identify dark matter — the mysterious stuff whose gravity appears to bind the galaxies — may have been stalking the wrong particle. In fact, a particle with some properties opposite to those of physicists' current favorite dark matter candidate — the weakly interacting massive particle, or WIMP — would do just as good a job at explaining the stuff, a quartet of theorists says. Hypothetical strongly interacting massive particles — or SIMPs — would also better account for some astrophysical observations, they argue.
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Physicists Identify Possible New Particle Behind Dark Matter More

Physicists Identify Possible New Particle Behind Dark Matter

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  • LAMP (Score:5, Funny)

    by darkain ( 749283 ) on Friday October 31, 2014 @04:20PM (#48282765) Homepage

    I always thought that WIMP (Windows IIS MsSQL PHP) was the opposite of LAMP (Linux Apache MySQL PHP)?

  • I understand the neutrino was theorized before discovery, but I just read the article and the chain of properties either WIMPs or SIMPs need to have, and they seem overly complex for something that there is no direct evidence for. Of course I am not a physicist. Just seems like we need better data collection of anomalous particle behaviors before investing much faith in such conjectures. Granted these theories could guide future experiments, but perhaps just sometimes theory gets a little too far ahead o

    • Re:My house of cards, taller than your house of ca (Score:4, Informative)

      by itzly ( 3699663 ) on Friday October 31, 2014 @04:34PM (#48282937)
      If you don't postulate some conjecture and start deriving all the required properties these particles are supposed to have, it's harder to find the proper experimental evidence you need to be looking for.
      • That's one way to work, and usually the most popular because much of the theoretical work is done by grad students hoping to get a PhD out of what they find. The other way is to collect as much data about the situation as you can so that you can narrow down the possible explanations. Of course, that way rarely leads to a PhD, so it's not used very often. Quite understandable.

        • Re: (Score:2)

          by Mal-2 ( 675116 )

          These days, the data comes from high-energy interactions, and often involves highly improbable events. If you don't already know what to look for, you will have to slow down and analyze every event. If you do know what to look for, you can dial up the frequency of events tremendously, paying close attention only to the ones that surprise you in some way. This cuts observation times from well beyond human lifespans, to a matter of a year or two. It makes them practical.

    • While everything you write is true, you leave out the actual importance of funding this: If SIMPS can be found, examination of their behavior in interactions would tend to prove or disprove fundamental ideas of the standard model.

      That's my take on this all, anyway.

      NB: I have been wrong before.

      • If SIMPS can be found, examination of their behavior in interactions would tend to prove or disprove fundamental ideas of the standard model.

        Yes, but that's what they said about WIMPS, too, and look where that has gone so far. (Pretty much nowhere.)

        Hey, if I come up with some complex theory postulating DUMPs (Dubious Universal Massive Particles), can I get funding too? After all, proving their existence would force major changes to the standard model.

        • Yes, yes and yes. That's exactly why I concentrated on "funding": The politics of it are critical. Lots of hypotheses exist, but few get to be funded and none without extensive peer review by proven fundraisers.

          It's a bit like The Movies in that there are lots of screenplays around, but only the ones producers think will turn a profit or an Oscar get produced.

          I tried to be non-cynical in my post.

        • Re: (Score:2)

          by Zynder ( 2773551 )
          I am pretty sure the first place you should search for DUMPs would be around Uranus. I'm not an astrophysicist though!

    • There's plenty of direct evidence for them. We've observed huge (galaxy scale) gobs of something that can't be matter as we know it but has mass.

      That long list of complex properties is what that something would have to have in order to explain the direct observations. And yeah, it's got to be pretty exotic and it proving hard to nail down exactly what it is.

      • There's plenty of direct evidence for them.

        There is no direct evidence of them. If there were, we wouldn't be having this discussion at all.

        We've observed huge (galaxy scale) gobs of something that can't be matter as we know it but has mass.

        They have not been observed. They have merely been inferred from the behaviour of things which have been observed. However, there are other possible explanations of those phenomena.

    • Re:My house of cards, taller than your house of ca (Score:5, Informative)

      by painandgreed ( 692585 ) on Friday October 31, 2014 @05:22PM (#48283439)

      I understand the neutrino was theorized before discovery, but I just read the article and the chain of properties either WIMPs or SIMPs need to have, and they seem overly complex for something that there is no direct evidence for. Of course I am not a physicist. Just seems like we need better data collection of anomalous particle behaviors before investing much faith in such conjectures. Granted these theories could guide future experiments, but perhaps just sometimes theory gets a little too far ahead of experimental evidence.

      Well, there is lots of evidence for something out there. This something, after coming up with other options and rejecting them through testing, must not interact with electromagnetic forces to a degree we can detect and have mass. Thus the "dark" and "matter". I am pa physicist and what you aren't seeing when you read these articles is a lot of math. It's complicated because physics at this level is really complicated and to come up with these hypothesis, they have to come up with something that fits what we already know about matter and the universe. That's going to involve a lot of graduate level mathematics and physics that describe a world that even physicists have a hard time wrapping their heads around. That's how particles get predicted, the math works out that way, and physics without the math is just philosophy. Sometimes you end up with something like string theory where the math works out (or seems to) but it can't be easily tested. At least these options can be tested.

      • Re: (Score:2)

        by hAckz0r ( 989977 )
        We need all the sciences to assemble the complete and real picture. In the case of dark matter we need the philosophy/logic to pull everyone else back down to earth right now. An example of where philosophy/logic comes into play is in falsifying a theory when it breaks the actual laws of physics and thus makes no logical sense. Case in point, "Abell 520 bullet cluster" vs "dark matter" theory. Assuming the most current gravitational lensing experiments are valid, the dark matter theory looks pretty dim righ
      • "can't be easily tested"..? Nonsense, there is NO test. String theory isn't a theory as it isn't testable.

        • Wasn't there an article years ago about a theoretical test that only required a particle accelerator the size of Mars' orbit?

          TBF, I think that would still qualify as "testable, just not with current technology".

    • " no direct evidence for"

      Where do you think that chain of properties comes from?

    • It seems to me that whatever particle they theorise, if they try hard enough they can find it sooner or later. That makes me suspect that none of them are actually real, but are just artefacts of the experimental methods, and indicators of some much more fundamental reality - which they are completely failing to see.

  • Would their force carriers be called... (Score:5, Funny)

    by Ken_g6 ( 775014 ) on Friday October 31, 2014 @04:30PM (#48282879) Homepage

    If the force carriers for ordinary matter are called bosons [wikipedia.org]...

    Then would the force carriers for SIMPs be called...SIMPsons?

    • These are not the SIMPletons you're looking for, move along.

    • If the force carriers for ordinary matter are called bosons [wikipedia.org]...

      Then would the force carriers for SIMPs be called...SIMPsons?

      You probably nailed it. Particle and theoretical physicists have quite the sense of humour. I'm sure if you send that name to those actually developing the theories that they would consider it.

  • Not only are they inventing a new particle, but a new force as well ? Which is needed to explain how the new particles behave ?

    Really this seems to be nothing more than an attempt to create an explanation that doesn't make predictions and is as removed from testability as possible.

    • Re: (Score:2)

      by mbone ( 558574 )

      Not only are they inventing a new particle, but a new force as well ? Which is needed to explain how the new particles behave ?

      Really this seems to be nothing more than an attempt to create an explanation that doesn't make predictions and is as removed from testability as possible.

      No, that would be sterile neutrinos.

      • Not only are they inventing a new particle, but a new force as well ? Which is needed to explain how the new particles behave ?

        Really this seems to be nothing more than an attempt to create an explanation that doesn't make predictions and is as removed from testability as possible.

        No, that would be sterile neutrinos.

        There's another candidate for dark matter but if I understand things correctly it's ruled out because of the needed distribution.

    • Re: (Score:1)

      by Tablizer ( 95088 )

      The new particle is called the wildcardion. It plugs gaps in theories nicely.

    • Re: (Score:2)

      by ThorGod ( 456163 )

      This was one thing I didn't quite grasp when I first hit particle physics in college. It really did seem like many things were invented to explain experiments..and thus they explained experiments.

    • Not only are they inventing a new particle, but a new force as well ? Which is needed to explain how the new particles behave ?

      If dark matter particles interacted with any of the known forces (apart from gravity), they'd interact with ordinary matter and we'd be able to see them -- in other words, they wouldn't be dark. Whatever dark mater is made of, it almost certainly involves a new and undiscovered class of particles. Most likely particles in that new class will couple to each other in new ways -- which is another way of saying they experience new forces.

      Really this seems to be nothing more than an attempt to create an explanation that doesn't make predictions and is as removed from testability as possible.

      Many of the less exotic ideas have been eliminated by experiment. Negat

      • Not only are they inventing a new particle, but a new force as well ? Which is needed to explain how the new particles behave ?

        If dark matter particles interacted with any of the known forces (apart from gravity), they'd interact with ordinary matter and we'd be able to see them -- in other words, they wouldn't be dark. Whatever dark mater is made of, it almost certainly involves a new and undiscovered class of particles. Most likely particles in that new class will couple to each other in new ways -- which is another way of saying they experience new forces.

        Really this seems to be nothing more than an attempt to create an explanation that doesn't make predictions and is as removed from testability as possible.

        Many of the less exotic ideas have been eliminated by experiment. Negative results don't make good headlines, but much progress has been made on the search for dark matter and the number of possible theories has been greatly reduced. There is a real need for new ideas of this type.

        Or it might be time to start looking at other things entirely. Especially seeing as there has already been a considerable amount of work on finding 5th forces both attractive and repulsive When new theories start contradicting experimental data or start making statements that are untestable, at some point you have to drop back and say you have been barking up the wrong tree.

        • Or it might be time to start looking at other things entirely. Especially seeing as there has already been a considerable amount of work on finding 5th forces both attractive and repulsive When new theories start contradicting experimental data or start making statements that are untestable, at some point you have to drop back and say you have been barking up the wrong tree.

          I'm not sure what you're getting at. Science follows a simple recipe: observe, predict, test. We observe that galaxies rotate in a manner that cannot be accounted for by our existing understanding of gravity and matter. A whole bunch of predictions have been made according to different ideas about how to account for galactic dynamics, from gas clouds to black holes to brown dwarfs to modified gravity to exotic particles. From time to time somebody comes up with a new idea to add to the list. Those pred

          • Or it might be time to start looking at other things entirely. Especially seeing as there has already been a considerable amount of work on finding 5th forces both attractive and repulsive When new theories start contradicting experimental data or start making statements that are untestable, at some point you have to drop back and say you have been barking up the wrong tree.

            I'm not sure what you're getting at. Science follows a simple recipe: observe, predict, test. .

            Nice of you to share that.

  • No one has yet lost any money betting against solutions for dark matter, so I am not going to get very excited about SIMPs (which, of course, are not really that new an idea anyway). Wait for it to get poked and prodded for a while, and then we'll see.

  • s/Identify/Hypothesize/ (Score:5, Insightful)

    by mcelrath ( 8027 ) on Friday October 31, 2014 @04:36PM (#48282951) Homepage

    No one has "identified" anything. This is a paper with a proposal, an idea, a hypothesis. Behind it lie a rather gigantic pile of assumptions and parameters to fit the data. It's long been speculated that Dark Matter may not be simple, but rather could be as complicated as the visible spectrum (which contains electrons, photons, atoms, and the entire periodic table). But there's a huge problem with making predictions in a strongly interacting theory: you generally can't. "Strong interactions" mean that most computations do not converge. For instance we cannot, from first principles, calculate the mass of any atomic nuclei.

    So this means the "dark matter sector" contains essentially a whole periodic table of stuff, and we're hopelessly unable to compute anything. This paper in particular ignores the possibility of bound states (e.g. atoms, mesons, etc) in the dark matter sector, which IMHO is just silly especially with strong interactions.

    • I agree with you in principle, but I have a couple quibbles with your argument. Firstly, there is, in fact, a branch of theoretical physics that derives particle masses from first principles: Heim Theory [wikipedia.org] (I'm not sure why the article is so short now; I remember it being much more extensive, with discussions of predicted vs. observed masses for most of the basic particles) apparently derived the basic particle masses from fundamental constants. But hardly anybody is working on it now, because it's pretty far

      • Him theory is not considered credible by anyone I've ever talked to (I am a theoretical physicist). I can't really say more, I haven't studied it.

        And we all hope a method to compute at strong coupling will arise. And if one does, one could computer the bound state spectrum of the dark matter sector, and do the calculation the authors suggest correctly. Maybe their suggestion is even correct, but their calculation is wrong without consideration of bound states.

  • Everyone is looking at the WIMPs or SIMPs. But what about the BLIMP in the middle of the room?

  • Style (Score:4, Informative)

    by Livius ( 318358 ) on Friday October 31, 2014 @06:06PM (#48283809)

    This is how science works.

    It's not pretty, so you don't have to like it, but your not liking it is not a valid criticism.

  • So if the dark matter would just get out of the way, we could see this new particle ALOT better, right?

    (the above question pretty much sums up my knowledge on this subject)

  • We seek it here, we seek it there... (Score:1)

    by Anonymous Coward

    the Scarlet Pimpernel

  • So, another hypothetical particle? (Score:1)

    by Anonymous Coward

    This hunt for "Dark Matter" really reminds me of the hunt for "Aether" way back when.

    If the large scale structures of the Universe are not matching to how our theories say they should then maybe, rather than just looking for voodoo particles, we should also be asking ourselves seriously why we are assuming that our current theories are totally correct.

    One thing that has bothered me about all the dark matter theories I have heard; if dark matter is only affected by gravity then what keeps it

    • I don't think we are assuming our current theories are totally correct, otherwise we wouldn't be looking for new physics (in the form of dark matter particles) to explain what we're seeing. Signs tend to indicate though that out current mode of thinking is correct but incomplete, as opposed to being completely wrong, which is why we're not throwing out everything and starting again from scratch.

  • another theory (Score:3, Funny)

    by slashmydots ( 2189826 ) on Friday October 31, 2014 @11:31PM (#48285459)
    I think that dark matter is made of a yet to be discovered material called math-errorium. You'll never guess why it hasn't been discovered yet.

  • The Real Reason Dark Matter Can't Be Seen

    The reason scientist can't find dark matter is that they're not looking in the right place. As soon as they look it is not dark matter but normal matter. This is because the Universe is very much like a game simulation in the computer where it only displays what you are looking at, not the things you're not looking at. This selective display saves computational resources allowing a higher, more realistic frame rate. Although the objects aren't displayed they still ha

  • "The Search for Dark Matter - Professor Carolin Crawford

    https://www.youtube.com/watch?... [youtube.com]

    If you are interested in astronomy you should check out the other videos of her from Gresham College. After Neil deGrass Tyson she's the only other person that makes me - who is only mildly interested in the subject - want to watch such hour log lectures all the way to the end. In other words: She's darn good at this!

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