LUX results: Dark matter hunt nears final phase

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Scientists could be nearing the final phase of the search for dark matter: the enigmatic substance thought to make up a quarter of our Universe.

The first results from a particle detector called LUX show it is the most powerful experiment of its kind.

It did not detect any dark matter during its first run, but scientists say it is poised to probe deeper than ever before during its second in 2014.

It has also ruled out earlier hints of dark matter shown by other experiments.

Dr Chamkaur Ghag, a collaborator on the LUX experiment from University College London, said: "If the dark matter is out there and if it interacts the way we think it does we should really start seeing it now."

Not finding any direct evidence for dark matter particles would mean that physicists would have to "go back to the drawing board", he added.

Written By: Rebecca Morelle
continue to source article at bbc.co.uk

9 COMMENTS

  1. If the dark matter is out there and if it interacts the way we think it does we should really start seeing it now.

    Presumably, scientists expect dark matter to interact a certain way. Interact with what, I wonder…

  2. £1 says they will not find anything. £2 says Dark matter does not exist, and all the evidence for dark matter is just bad observations.

    (promoting/provoking science in my own little way)

    • In reply to #3 by old-toy-boy:

      £1 says they will not find anything. £2 says Dark matter does not exist, and all the evidence for dark matter is just bad observations.

      (promoting/provoking science in my own little way)

      Sounds plausible. I don’t not enough of the science to make an informed decision though :)

    • In reply to #3 by old-toy-boy:

      £1 says they will not find anything. £2 says Dark matter does not exist, and all the evidence for dark matter is just bad observations.

      (promoting/provoking science in my own little way)

      I have a $50 bet riding. I aim to collect. Dark Matter is Post-Modernist codswallop.

      As a tool to investigate the Universe, philosophy is more accessible to me than science and sometimes it allows me to take sides in a scientific debate. There are huge philosophical problems with Dark Matter as a substance. It’s not like the discovery of the neutrino or other material phenomena. It’s totally sloppy, and far too few science popularizers highlight how baseless the assertion is (I’m looking at you, Kaku). We just found a freakin’ blackhole in the center of every galaxy, and act like we know how that accounts for galactic architecture… mmmmm right. If they did find Dark Matter, the ramifications on epistemology would be dire. Oh god… it would be worse than Hawking claiming information could be lost.

      I’ve been trying to find out if there are models that account for the velocity of matter, like what percentage of matter in a galaxy travels above 20% of C? Could Dark Matter just be really fast matter. Could that account for the increased mass? I know hardly anything about physics, but I just wonder if increased mass from velocity has been tallied up.

  3. What if dark matter can’t exist near ordinary matter. Any detector made of ordinary matter is bound to fail. You would have to find it by something it does, rather than detecting it directly.

    I understand that dark matter cannot be made of any of the known particles. But if that is so, does that not mean our current theory is wrong, quite unlike a number of scientists have claimed, since our theory says there cannot be anything else?

    I asked an astronomer about a number of speculations about what dark matter might be. To my surprise, all of them had already been thought of and discarded. My strangest one is that Newton’s law of gravitation is not quite correct. f = g( m1 * m2 ) / d ^ 2. The 2 is not quite 2 or is some similar function makes it look as if g varies slightly with distance.

  4. Let me clarify a few things.

    Roedy We must suspect something about dark matter if we built a detector for it. What are we looking for?

    We’re looking for interactions of dark matter particles with nuclei (or, in more recent experiments, electrons) which result in the latter emitting photons.

    godzillatemple Presumably, scientists expect dark matter to interact a certain way. Interact with what, I wonder

    More to the point, interact how? Dark matter doesn’t interact electromagnetically, but is expected to interact with more familiar particles via the weak interaction.

    old-toy-boy all the evidence for dark matter is just bad observations

    This many experiments are not going wrong. There’s something to explain. Whether the correct explanation is new gravitating matter, a modification to how strong gravity is or a modification to how strong a force is required to effect a given acceleration is the crux of the debate. The first option (dark matter) is the one that’s easiest to reconcile with what we know of otherwise successful physical theories.

    Roedy What if dark matter can’t exist near ordinary matter… You would have to find it by something it does, rather than detecting it directly… dark matter cannot be made of any of the known particles… our theory says there cannot be anything else… all of them had already been thought of and discarded

    Firstly, what do you mean, “can’t exist near”? Put them in the same box; they’re near each other. If you want to claim dark matter repels ordinary (i.e. baryonic) matter, that’s an example of an interaction. Secondly, what is “our theory” that precludes undiscovered particles? The Standard Model’s predicted particles have all been found, but physicists conjectured other particles long before dark matter was observed; indeed, dark matter could easily be composed of particles in supersymmetric theory called LSPs. Thirdly, while a number of objections have been raised to various dark-matter and alternatives-to-dark-matter models, I wouldn’t go so far as to say all ideas we’ve come up with have been refuted and discarded.

    This Is Not A Meme Dark Matter is Post-Modernist codswallop… There are huge philosophical problems with Dark Matter as a substance. It’s not like the discovery of the neutrino or other material phenomena. It’s totally sloppy… We just found a freakin’ blackhole in the center of every galaxy, and act like we know how that accounts for galactic architecture… If they did find Dark Matter, the ramifications on epistemology would be dire… I just wonder if increased mass from velocity has been tallied up.

    Firstly, postmodernist in what sense? Usually when I hear something being criticised for that relativism is being alleged, but that’s clearly not applicable here. Secondly, dark matter is not sloppy; if you go through the maths of it, it makes a lot of sense as a model in particle physics. Thirdly, since stars move at a fraction of 1 % of the speed of light (which causes a mass change of at most a few parts per million), we can indeed confirm the stars and central black holes in galaxies aren’t nearly sufficient to generate the observed gravity experienced by stars at the edge of a galaxy.

    • In reply to #7 by Jos Gibbons:

      Firstly, postmodernist in what sense? Usually when I hear something being criticised for that relativism is being alleged, but that’s clearly not applicable here. Secondly, dark matter is not sloppy; if you go through the maths of it, it makes a lot of sense as a model in particle physics. Thirdly, since stars move at a fraction of 1 % of the speed of light (which causes a mass change of at most a few parts per million), we can indeed confirm the stars and central black holes in galaxies aren’t nearly sufficient to generate the observed gravity experienced by stars at the edge of a galaxy.

      Thanks for the general assessment of my question about velocity and mass. I was hoping my speculation was completely naive and easily dismissed. I wondered about objects accelerated by the blackhole, and which would imply a lot of fast stars. Still, I wonder about dust… and hope that speculation is deeply flawed too.

      Post Modernism aggressively infected the sciences, but hit its head against the wall of physics. Cynically, I believe the Sokal Hoax was very effective, and that the madness of PoMo would have otherwise done much more damage. I refer to Dark Matter as PoMo, as I would refer to “fine tuning” as theistic. There is a basic set of assumptions that are not immediately evident, philosophical or cultural influences that we can’t help but bring to science (history shows these assumptions get discarded with further discovery). Science is without metaphysics, and I believe people have a difficulty processing information on such a humble level, without integrating it into a worldview (such as turning Darwinism into a socio-economic theory). PoMo tried to embed itself in particle-physics, and I blame popularity of gravitons and Dark Matter on its academic influence.

      Science is ever evolving and not constrained by anything except results, whereas philosophies have definite parameters. Of the major philosophical stances, only PoMo epistemology can allow for gravitons, because it doesn’t really reconcile the fundamental interaction problem. The gravitons would need gravitons, and only PoMo can handle ‘turtles all the way down’ solutions of infinite regress. PoMo has a fetish for ignorance and the unknowable, and Dark Matter and Dark Energy have high sex appeal for this reason.

      The math of Dark Matter is elegant, and I’m very impressed by the distribution models. By sloppy I mean mixing unreconciled bodies of knowledge (particle physics/quantum, gravity/relativity), to make an ontological claim. The neutrino was predicted out of the particle physics data, and when tested on the large-scale, Einsteinian theater of stars, we found neutrinos had mass. That’s fine, a great exhibition of science. Dark Matter is a particle physics explanation for galactic architecture. Something is bound to go wrong. It’s too much of a departure from assumptions about epistemology. We don’t have a theory of gravity that necessitates a substance to account for the difference. There could be something fundamentally different about the nature of gravity.

      If Dark Matter is found, Hume is dead. It would have tremendous shake-ups in philosophy. I believe it would be worse than Hawking’s loss of information hypothesis. It would allow for story telling to become a viable form of evidence, and remove the restrictions on synthesizing data sets… which is all just a bit medieval. While philosophy must change in accordance to science, I can’t think of a scientific debate that ever resolved with a fundamental change like Dark Matter would require. It wouldn’t be the end of maths or logic, but it would be huge…

      damn, now I kinda want ‘em to find Dark Matter. I don’t mind the $50.

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