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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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  • Hello /. Editors. (Score:3, Informative)

    by pb ( 1020 ) on Wednesday July 28, 2004 @02:58AM (#9819624)
    It is spelled 'existence'; it's even correct in the article body. So please fix it in the title.
    Thank you.
  • Re:What? (Score:5, Informative)

    by Alsee ( 515537 ) on Wednesday July 28, 2004 @05:08AM (#9819929) Homepage
    as I understand it, we have an assumption of science that requires that we account for mass that is not present. Voila! Dark Matter

    You have it backwards. They are trying to account for matter that apparently *is* present, we just can't see it and don't know what it is.

    There is lots of evidence that there is *something* there, we can see its gravitational effects on the stuff we can see. Gravitational lensing and orbital speeds. And there's plenty of other evidence I don't know offhand.

    If you can somehow explain all of the evidence without "dark matter", well you'll be almost as famous as Einstein.

    -
  • Re:When? (Score:4, Informative)

    by Oddly_Drac ( 625066 ) on Wednesday July 28, 2004 @06:17AM (#9820092)
    "Could it be that we are killing global paradigms ?"

    Nope, it's just that paradigm shifts seem a lot more obvious in retrospect once development has followed a decent amount of testing. It could be argued that we're currently in the grip of a paradigm shift that's affecting society as a whole, given that global, affordable communications have really started to take off in the past 20 years.

    On the other hand, there isn't a lot of 'pure' research being undertaken, which means that you're limited to the postgrad, postdoctoral academic work these days.

  • by erik_norgaard ( 692400 ) on Wednesday July 28, 2004 @06:40AM (#9820132) Homepage
    There are dectectors that do detect something which is generally accepted as being neutrinos.
    The interact very weakly, has an energy less than 29 eV and travel close to the speed of light.

    Since they interact so weakly they can be used to detect supernovas before the supernova is visible on the sky.

    The problem is that the sensitivity of the current detectors does not allow to determine wether these has a mass and travel a little less than the speed of light or if they are massless. Neutrinos with mass can resolve the dark energy problem.

    Another problem is that the detectors does not detect the amount of neutrinos to be expected.
  • Neutrinos. (Score:4, Informative)

    by Christopher Thomas ( 11717 ) on Wednesday July 28, 2004 @01:55PM (#9823017)
    The problem is that the sensitivity of the current detectors does not allow to determine wether these has a mass and travel a little less than the speed of light or if they are massless. Neutrinos with mass can resolve the dark energy problem.

    Actually, it's the dark _matter_ problem massive neutrinos address, and they only form part of the puzzle ("hot dark matter").

    Dark _energy_ appears to be a repulsive force intrinsic to space. This proposed model is one take on a mechanism for it.

    Neutrino mass has also been pretty conclusively demonstrated by observations of neutrino _oscillation_ (changing of flavour), which cannot occur if neutrinos are massless. This incidentally also solves the solar neutrino problem (the detectors producing shortfall measurements could only detect one type of neutrino, while solar neutrinos were oscillating between all three types in transit, resulting in many not being detected).

    Most of these developments happened within the last decade or so. We're in a very interesting time for particle physics (between new observations, new mathematical approaches to applying string theory, and new approaches to modelling gravity that aren't string theory).
  • Article text (Score:3, Informative)

    by TMB ( 70166 ) on Wednesday July 28, 2004 @03:09PM (#9823899)
    Here's a full pre-print of the article [lanl.gov].

    [TMB]
  • Re:What? (Score:4, Informative)

    by Ayaress ( 662020 ) on Wednesday July 28, 2004 @05:49PM (#9825798) Journal
    Much as I have a rule againt replying to posts that resort to insults, I always end up doing it.

    Your problem comes from the fact that you, like so many other people, insist on a ass-backwards concept of how science works.

    These scientists are not creating a theory. You don't have a theory unless you have observation to base it on.

    They're making a hypothesis, which is just that - a hypothesis. They throw out a few ideas that give them some inkling of what to look for. It doesn't tell us anything, but it grows out of things we already know.

    Then, they go to the observation, and try and see what there actually is. You don't need a hypothesis to do observation, but with extremely complex stuff like this, it's a good idea to know what you're looking for first, or you'll be hit with information overload. They've already got a few thousand particles on the books, so if they don't have an idea of a new one they're looking for, they'll never find it underneath all the protons and electrons and pions and morons. If the observations fit the hypothesis, they start throwing it all into equations.

    When they derive equations that hold true, it becomes a law. Law still doesn't really tell you very much. So e=mc^2. It doesn't tell you anything useful about mass or energy.

    Theory is the highest level of scientific understanding, and is not just far above theory, but it's actually higher on the scale than law (which is why the "If it was true, it wouldn't be a theory anymore, it would be a law" is wrong. You go from hypothesis to observation to law and lastly to theory).

    It comes after you've made your hypotheses, observed confimation, and derived laws from the observation. Theory tells you WHY your hypothesis worked (or didn't, as they case may be), and why the laws do what they do. All the fancy things you can read out of e=mc^2 (like mass being variable, energy and matter being interchangeable, and so on) are Theory. Theory outranks law.

    All we have here is hypothesis, nothing more. You're trying to equate hypothesis with theory, but they're completely different things, separated by two levels of understanding.

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