Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

B The observed spatial distribution of matter

  1. Oct 14, 2016 #1

    wolram

    User Avatar
    Gold Member

    Is this a ground breaking observation or does it agree with other observations?




    atures and the Wing-Ford band, presented in a recent paper.

    arXiv:1610.03854 [pdf, ps, other]
    The observed spatial distribution of matter on scales ranging from 100kpc to 1Gpc is inconsistent with the standard dark-matter-based cosmological models
    Pavel Kroupa (Bonn, Prague)
    Comments: 14 pages, LaTex, published in "Cosmology on Small Scales 2016", Michal Krizek and Yurii Dumin (Eds.), Institute of Mathematics, Czech Academy of Sciences, Prague: ISBN 978-80-85823-66-0
    Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA)
    The spatial arrangement of galaxies (of satellites on a scale of 100kpc) as well as their three-dimensional distribution in galaxy groups such as the Local Group (on a scale of 1Mpc), the distribution of galaxies in the nearby volume of galaxies (on a scale of 8Mpc) and in the nearby Universe (on a scale of 1Gpc) is considered. There is further evidence that the CMB shows irregularities and for anisotropic cosmic expansion. The overall impression one obtains, given the best data we have, is matter to be arranged as not expected in the dark-matter based standard model of cosmology (SMoC). There appears to be too much structure, regularity and organisation. Dynamical friction on the dark matter halos is a strong direct test for the presence of dark matter particles, but this process does not appear to be operative in the real Universe. This evidence suggests strongly that dynamically relevant dark matter does not exist and therefore cosmology remains largely not understood theoretically. More-accepted awareness of this case would by itself constitute a major advance in research providing fabulous opportunities for bright minds, and the observational data strongly suggest that gravitation must be effectively Milgromian, corresponding to a generalized Poisson equation in the classical limit. Thus, physical cosmology offers a significant historically relevant opportunity for ground-breaking work, at least for those daring to do so.
     
  2. jcsd
  3. Oct 14, 2016 #2

    phinds

    User Avatar
    Gold Member
    2016 Award

    This smacks of conspiracy theory nonsense and thus in my mind reduces the credibility of what goes before. Could be just me though.

    Also, I don't know what he means by "dynamical" dark matter, do you?
     
  4. Oct 14, 2016 #3

    wolram

    User Avatar
    Gold Member

    I admit that i am not qualified to comment , but the searches for Dark matter do keep coming up empty and seem to get more radical.
     
  5. Oct 14, 2016 #4

    phinds

    User Avatar
    Gold Member
    2016 Award

    I assume you are not talking about searches for the existence of dark matter but rather are talking about searches for specific particle types, yes?

    Also, in the synopsis you presented, the statement "Dynamical friction on the dark matter halos is a strong direct test for the presence of dark matter particles, but this process does not appear to be operative in the real Universe." Doesn't seem to make sense but that could well be because I don't understand what he means by "Dynamical friction on the dark matter halos". Certainly the Bullet Cluster seems to show unequivocal evidence of dark matter halos.
     
  6. Oct 14, 2016 #5

    wolram

    User Avatar
    Gold Member

    Yes i am referring to the particle, if one can not find some thing one expands the search area, if it is not found then it may never of existed.
     
  7. Oct 14, 2016 #6

    phinds

    User Avatar
    Gold Member
    2016 Award

    Do you doubt the existence of dark matter?
     
  8. Oct 14, 2016 #7

    wolram

    User Avatar
    Gold Member

    I am afraid i do, there are umpteen searches going on with no results to date.
     
  9. Oct 14, 2016 #8

    wolram

    User Avatar
    Gold Member

  10. Oct 14, 2016 #9

    phinds

    User Avatar
    Gold Member
    2016 Award

    So you don't believe the bullet cluster exists and exhibits the characteristics of dark matter? I think you are getting confused by the fact that we don't know what dark matter IS. We certainly know a lot about how it works, and to doubt it's existence seems to me to be just silly at this point. After all "dark matter" is just a name. It is a placeholder that stands in for the phrase "what the hell ever it is that is causing these effects that are clearly shown by empirical evidence". It isn't even certain at this point that it is "matter", although I think the consensus is that it has to be. Whatever it is, it certainly exists. Do you really dispute that?
     
  11. Oct 14, 2016 #10

    wolram

    User Avatar
    Gold Member

    I do not think i am being silly, to date we only have a conjecture that dm exists, may be the bullet cluster is a red herring I do not know, but i would need more evidence of its existence to stake any money on it.
     
  12. Oct 14, 2016 #11

    phinds

    User Avatar
    Gold Member
    2016 Award

    So you think galactic rotation curves showing that SOMETHING is there and it is overpowering normal matter are just conjecture? Seriously?
     
  13. Oct 14, 2016 #12

    Chalnoth

    User Avatar
    Science Advisor

    There's no reason at this point to doubt dark matter. Most models of dark matter that physicists have come up with are extremely difficult to detect regardless. It's disappointing that we haven't detected it yet, but that non-detection means very little.

    What does matter is that models that try to explain the observations without dark matter are invariably very complex and contrived.
     
  14. Oct 14, 2016 #13

    PeterDonis

    User Avatar
    2016 Award

    Staff: Mentor

    Thread closed for moderation.

    Edit (from Dale): this thread will remain closed. In a thread about unusual journal articles it can be difficult to stay within the bounds of professional speculation and avoid crossing into personal speculation. This thread has crossed that line.
     
    Last edited by a moderator: Oct 15, 2016
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: The observed spatial distribution of matter
Loading...