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Science

Physicists Postulate Existance of New Particle 139

corngrower writes "University of Washington physicists postulate the existence of a new particle called the acceleron which links dark energy with the neutrino. The theory offers an explanation for the recent discovery of the accelerating expansion of the universe."
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Physicists Postulate Existance of New Particle

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  • When? (Score:2, Interesting)

    by PedanticSpellingTrol ( 746300 ) on Wednesday July 28, 2004 @03:00AM (#9819632)
    As soon as the next Copernicus, Newton, Einstein, Planck or Hawking comes along. Considering the exponential population growth lately, and assuming a fixed ratio of paradigm-defining supergeniuses to the general population, we're probably overdue.
  • Re:When? (Score:4, Interesting)

    by selderrr ( 523988 ) on Wednesday July 28, 2004 @05:13AM (#9819937) Journal
    yes, i find it fascinating indeed that a paradigm genius hasn't show up in the past 30 years. Or at least not on a scientific level with global implications... Has our science grown so specialised indeed ? Copernicus, Newton and to a certain degree also einstein & planck were universal scientists. Modern day scientists work themselves deeper & deeper in smaller and smaller subfields of an allready tiny science topic... Could it be that we are killing global paradigms ?
  • Re:What? (Score:3, Interesting)

    by ghostlibrary ( 450718 ) on Wednesday July 28, 2004 @08:36AM (#9820635) Homepage Journal
    "Is it just me, or are scientists trying to make science fit the theory?"

    It's neither :) The main thing is, when faced with a problem in the current theory, the scientists are saying "Okay, maybe it's _X_"-- but they make sure _X_ is testable.

    That's what keeps it from just being pseudoscience or fiction. As long as a theory is testable, it can be as wacky as you want.

    Subject to the usual criteria and Occam's Razor, of course-- really wacky ideas (like 'the Big Bang' or 'Sun is center of solar system') take a little time for the advancements needed to test them.

    Dark Matter may be a hack or totally wrong, but at least it's well-defined and _testable_. Alternative theories (like a modified gravity law or a new particle type) are equally wacky and equally testable. I can't wait to see which wins!
  • Re:What? (Score:3, Interesting)

    by nine-times ( 778537 ) <nine.times@gmail.com> on Wednesday July 28, 2004 @01:12PM (#9822814) Homepage
    GP: Is it just me, or are scientists trying to make science fit the theory?

    P: It's just you. Scientists come up with a theory, then try to find out whether it is true or not. What you're describing is best referred to as pseudoscience...

    Well, then Mr. Smarty-Pants, I guess the question then is whether most people who describe themselves as "scientists" are, in fact, scientists, or are they "pseudoscientists"?

    I mean, it seems like that's the question the OP was asking. Are these "scientists" making a theory to fit the physical world we live in (which would be proper), or are they making up imaginary particals so they can pretend the physical world we live in fits their theory? It's a good question.

  • Re:Hmmm (Score:2, Interesting)

    by nine-times ( 778537 ) <nine.times@gmail.com> on Wednesday July 28, 2004 @02:16PM (#9823256) Homepage
    observations don't match your theory???

    postulate a new particle...

    Well, it's even worse, I think, then physicists' normal tendancies to make up new particals and forces whenever they get stuck. If you read the article, it sounds like these physicists are trying to describe "dark energy", and the only way they can think to do this is to say nuetrinos have mass. OK, but this means a lot of what they thought about nuetrinos makes no sense- and if you ask me, nuetrinos already fit into the classification of "suspect particles".

    So... Here's the situation:

    A) We've made up one thing (dark energy). We made it up in order to cover the fact that our current understanding of physics doesn't make sense of universe, at least insofar as we are able to measure it.

    B) To explain this made-up thing, we take a particle we've made up for similar reasons, and change what we've been saying it is. But we change it in such a way, so that these particles don't explain the equations we made it up to explain in the first place!

    c) So, our solution: make up another particle, which is undetectable, and does nothing but make our first made-up particle work the way we need it to again. Why? Because we've postulated it doesn't work the way we had made it up to work. Therefore it doesn't cover up the hole in our understanding that we made it up to cover, which was the reason we made it up in the first place.

    Achk! I admit this post is a bit of a jumble, but that's the way it needs to be to accurately describe modern particle physics.

  • Re:What? (Score:5, Interesting)

    by ekuns ( 695444 ) * on Wednesday July 28, 2004 @11:20PM (#9828003) Journal

    Are scientists being close minded and protective of their current understanding, and plowing ahead on a path that they should, within reason, be able to predict is heading the wrong way?

    I'm a particle physicist by training (although not by career). The answer to this question, IMHO, is "No." Most particle physicists I know -- of many dozens -- would prefer to find something that the current standard models clearly cannot explain. The problem is that with only a few tweaks, so far, the current standard model is been able to predict just about every measurement thrown its way, and with a dismaying degree of accuracy.

    See, here's the problem. The standard model of particle physics accurately predicts all measurements made thus far to as much accuracy as people have been able to bring the calculations. Many consider the standard model to be quite ugly because it has so many "arbitrary" parameters with no underlying theory of where those values come from: It has about 20-ish measured values that go into it. Many of those arbitrary values are the measured masses of particles, and the measured interaction strength of the three forces (not including gravity).

    All of the physicists I know and most of the physicists I've ever met in the particle physics field are quite willing to be pursuaded by a new theory, but no such theory has presented itself. Some have thought that string theory will be that paradigm shift, but so far there is not enough evidence to prove or disprove.

    When a convincing quantum theory of gravity appears, that will probably fix many of the complaints people have about the standard model.

    So the issue at hand here is some scientists who are making a hypothesis within the current framework, extending the current framework, to explain some seemingly unrelated measurements. This is not epicycles on top of epicycles, although it might appear as such.

    From reading the article, it appears that this hypothesis is disprovable, and thus a strong scientific hypothesis. It will be interesting to see how this theory holds up against evidence.

  • Re:What? (Score:4, Interesting)

    by ekuns ( 695444 ) * on Thursday July 29, 2004 @01:41AM (#9828654) Journal

    I guess you wouldn't believe me if I told you I knew more than might be immediately obvious

    I hadn't yet made any assumptions about what you do or do not know. I aim to make as few assumptions as I can, because assumptions are so frequently incorrect.

    And yes, many of these people I have in mind are even "scientists" by trade.

    I'm open to believing this. I have definitely encountered some "true believers" in physics and in other sciences. Most of the people I know and knew did not fall into that camp, but there's a selection there because I tend to find "true believers" annoying. Because by definition they are not open to evidence.

    I have changed my mind on major scientific issues several times during my life. I expect I will do so on major theories at least a few more times. I certainly hope so! The alterntative is boring! Personally, I hope that they do NOT find the Higgs Boson. It will be much more interesting if they do not find it, because it is getting more difficult with time to construct a theory that can explain why we haven't found it. If the Higgs Boson is not found in the next decade, that will have serious consequences for many current theories.

    Along with that, I will say that very few of non-believers I know would say that quantum machanics "makes sense".

    I understand what you are saying. But quantum physics really does make sense. It's just not intuitive, because our experience with the macroscopic world does not correlate well with the behavior of very small things. You're right in that I give huge value to a theory that predicts accurately, and that I value more highly a theory with predictive power than a theory with less predictive power that is more understandable.

    To a point. Adding epicycles upon epicycles blindly can become an obsessive exercise in not looking elsewhere. The good news is that lots of physicists are looking strenuously for alternative theories. Practically all of these theories get disproven within a few years, but eventually, someone will find a cleaner more beautiful theory than the current standard model -- I hope! -- that has the same or better predictive power as the current model.

    The big philosophical question once the math works is -- what does the math mean? Many physicists happily totally ignore that question and just rely on the predictive power. Some other people get the accuracy of prediction confused with the concept of whether the theory or model is "true." Hey, it's just a model! No-one I know thinks that the current theory is the end of the road. What does the math mean? That is an excellent question. I am hoping for a new theory that explains at least some of the following questions:

    Why three dimensions of space, and not two or four? (I'm ignoring any "curled up" dimensions which we cannot participate in.) Why do the particles we know of have the masses they have? Are space and time continuous, or discrete? What causes mass to exist? Why three "generations" of quarks and leptons, and not two or four? Is there a reason that the (observable) universe has the amount of energy that it does, and not less or more?

  • Re:What? (Score:2, Interesting)

    by edgar_is_good ( 684481 ) on Thursday July 29, 2004 @11:54AM (#9832322)
    Gravitons are massless (although Kaluza-Klein gravitons are not), so plain gravitons would make bad dark matter as they wouldn't clump and don't redshift appropriately.

    Also, to radiate gravitational energy, there has to be matter on the other brane (e.g. dark matter).

    I find it funny that you appeal to string theory because you don't like new particles. The thing with string theory is that it predicts a huge number of unseen particles, some of which could be dark matter and accelerons. You can't really take the string theory without new particles.

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