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Galaxies Floating on a Dark Matter Stream

Posted by Zonk on Sun Jan 15, 2006 05:41 PM
from the sounds-like-my-teenage-years dept.
Space Science
Darkman, Walkin Dude writes "A team in Switzerland has discovered that most of the small satellite galaxies around the Milky Way's near-twin, Andromeda, are lined up in a single plane that slices through Andromeda's spiral disc. Using images from the Hubble space telescope, soon to be decommissioned, the researchers found that 9 of the 14 of Andromeda's satellites lay on a relatively narrow plane bisecting Andromeda. From the article: 'The team believes the plane could have formed in several ways. In one scenario, the galaxies may have fallen towards Andromeda along an invisible filament of dark matter. Computer simulations show these filaments can form a cosmic web along which galaxies flow.'"
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  • Sombrero Galaxies and You (Score:5, Interesting)

    by eldavojohn (898314) * <my/.username@@@gmail.com> on Sunday January 15 2006, @05:42PM (#14477855) Homepage Journal
    These are called Sombrero Galaxies [nasa.gov]. I believe M 104 [wikipedia.org] is the most famous since it was first noticed on May 11th, 1781.

    Does dark matter hold our universe together in a web? Perhaps, though this would mean that there is no such thing as truly empty space as a small amount of dark matter would have to exist. Perhaps what lays beneath the edges of our universe is nothing in the sense of it being devoid of dark matter?

    Check this out:
    Consider this fact: In the air we breathe, each cubic centimeter contains roughly 5 X 1019 atoms. In contrast, the intergalactic medium has a density of only 10-6 particles per cubic centimeter--each atom inhabits a private box a meter on each side. This would seem to suggest that there is not much matter in the intergalactic medium. But, given the enormous volume between the galaxies, it quickly adds up: The combined atomic mass of intergalactic gas exceeds the combined atomic mass of all the stars and galaxies in the universe--possibly by as much as 50 percent! There is indeed something in empty space
    From this article [americanscientist.org].

    While this article only mentions computer simulations, many scientific groups have gone along further researching, convinced that the cosmic web does exist [ociw.edu]. Some people [roe.ac.uk] have based most of their work on dark matter and the cosmic web though I believe it is still speculation [wikipedia.org] and has yet to be accepted by the science community as a whole. I've read some crazy stuff about dark matter, like how it might be the "gravity particle" that is attracted to matter uniformly and causes the gravitational pull between objects. And even crazier books suggesting that the only way we'll ever be able to communicate between parallel existences is by lowering and raising these gravity particles.

    Now, the slashdot community seems to be fairly educated and extremely opinionated so how about it--does dark matter exist? If so, since it is very difficult to detect, what are its defining properties?

    • Re:Sombrero Galaxies and You (Score:5, Funny)

      by gEvil (beta) (945888) on Sunday January 15 2006, @05:46PM (#14477878)
      Does dark matter hold our universe together in a web?

      I think it's more like invisible strands of spaghetti.

    • Bigger mystery (Score:2, Funny)

      by Anonymous Coward
      How the fuck did you write such a thorough and cogent response as a FIRST POST nonetheless??!?!?!
    • You cant really tell apart if you are reading science and pseudoscience (talking about the "parallel existence" stuff). And i seriously dont know why you think that the graviton is dark matter... or are you mixing this part up and mean the higgs boson?

      About this "web of dark matter": The WMAP data of the galactic background STRONGLY supports this hypothesis. The anisoropy is just too large, and too soon to be explained by non-external (i.e. non-photon interacting) gravitational influences.

    • Re:Sombrero Galaxies and You (Score:4, Informative)

      by Ckwop (707653) * <Simon.Johnson@gmail.com> on Sunday January 15 2006, @06:43PM (#14478172) Homepage

      Now, the slashdot community seems to be fairly educated and extremely opinionated so how about it--does dark matter exist? If so, since it is very difficult to detect, what are its defining properties?

      If this [cerncourier.com] is correct, then the Dark Matter riddle has been solved. Basically, it was due to the fact that scientists thought they could safely use the Newtonian limit to General Relativity with galaxies. They were wrong and Dark Matter is a result of this error.

      This was reported [slashdot.org] on Slashdot not to many moons ago.

      Simon

      • one paper was written, and it has (as far as i know) been proven to be correct. saying that dark matter has been disproved because of just one paper is foolish. scientific understanding is based on replication of results. you should wait until they are replicated. this is the problem with the media they lean on institutions to releases there informations before they are ready.

        • Re:Sombrero Galaxies and You (Score:5, Insightful)

          by drudd (43032) on Sunday January 15 2006, @09:03PM (#14478819)
          The current consensus is that the paper is fundamentally flawed, and that when done correctly non-linearities from GR cannot explain the flat rotation curves of spiral galaxies (not to mention the vast amounts of other evidence for dark matter including hot gas in galaxy clusters, fluctuations in the cosmic microwave background, strong lensing arcs in clusters, weak gravitational lensing by galaxies, the distribution of galaxies on large scales, etc).

          Unfortunately, the general public only hears about the initial press release, not the work of many other scientists in debunking those results.

          Doug

      • Re:Sombrero Galaxies and You (Score:5, Informative)

        by Stalyn (662) on Sunday January 15 2006, @08:51PM (#14478759) Homepage Journal
        Might want to do some actual research [arxiv.org] on the subject. From that list there are no articles in support of the Cooperstock-Tieu model other than a response by the orginal authors. The theoretical arguments and evidence against the model are quite convincing.

        Dark matter is just the best model we have right now. It also amazes me how much Slashdot is against the dark matter model. Why is that?
        • Well, dark matter is similar to claiming that you have an invisible red dragon in your basement and that this invisible red dragon is the master of the universe. If it cannot be proven to exist, then it is on the same level as religion and intelligent design and incompatible with science. Pure conjecture, fantasy, nonsense, bull...
          • Actually dark matter can be proved or disproved... it just hasn't been yet. Also there is indirect evidence for dark matter. Do you believe in String Theory? Dark matter has more evidence and theoretical weight than string theory.
            • Sure, seeing as there's no evidence for string theory and no evidence for Dark Matter we are currently 0 to 0. Now, string theory is an attempt to tie quantum mechanics together with relativity and kind of does that. But, Dark Matter is just an attempt to fix what we speed we think galaxies should rotate at according to Newton and what speed they do rotate at.

              String theory at least has meshing two obviously true theories together, whereas Dark Matter has the job fixing bad math. And if this article's sugg
              • Dark matter has vast (let me repeat, VAST) amounts of evidence beyond rotation curves of galaxies. It is supported by weak and strong gravitational lensing measurements, the clustering of galaxies, flucutations in the cosmic microwave background, hot gas and random motions of galaxies in galaxy clusters...

                All of this evidence is sufficient to say that either 1) dark matter exists or 2) our theory of gravity is broken in exactly the way necessary to seem like there's dark matter when there really isn't. #1
        • "It also amazes me how much Slashdot is against the dark matter model. Why is that?"

          Selection bias.

          Those with an axe to grind shout the loudest and post the most often. The silent majority just keep scrolling.

    • Empty Space (Score:3, Interesting)

      by jd (1658)
      There is no such thing as empty space, as that would violate all kinds of laws of physics. (It would exist in a constant state of entropy, there would be zero quantum uncertainty, it would allow for the possibility of an absolute frame of reference, etc.)

      In general, the popular belief is that ALL of space is filled with "quantum foam", which contains a mass of virtual particles whose sum (over any statistically significant volume) will be zero. These virtual particles are not "dark matter", precisely for th

  • ID (Score:5, Funny)

    by SoulMaster (717007) * on Sunday January 15 2006, @05:57PM (#14477942)
    In another scenario, the Intelligent Designer put them on that specific plane just to see how long it took before somebody noticed and claimed that it must be Dark Matter.
    • "In another scenario, the Intelligent Designer put them on that specific plane just to see how long it took before somebody noticed and claimed that it must be Dark Matter."

      Yeah yeah, we get it, fanatics suck. Let's not be fanatical about bringing up the fanaticism of the fanatics, k?
    • ...or on the other hand it might be a total coincedence that in this huge (or infinite?) universe there is a small number of galactical objects that accidentally appear to be in a line?

      We can't be certain just now, but I think Occam would agree with me.

    • Potestatem obscuri lateris nescis.

      - You don't know the power of the dark side.

  • Eric Lerner (Score:5, Interesting)

    by Bloater (12932) on Sunday January 15 2006, @06:19PM (#14478052) Homepage Journal
    The team believes the plane could have formed in several ways. In one scenario, the galaxies may have fallen towards Andromeda along an invisible filament of dark matter. Computer simulations show these filaments can form a cosmic web along which galaxies flow.'


    Eric Lerner [wikipedia.org] is looking less and less like a crank with every new cosmological experiment, I think this is exactly what his plasma filament theory [bigbangneverhappened.org] of the intergalactic medium has been predicting.

  • In another scenario... (Score:5, Funny)

    by Noxx (74567) on Sunday January 15 2006, @06:38PM (#14478155)
    In one scenario, the galaxies may have fallen towards Andromeda along an invisible filament of dark matter.

    In another scenario, the Flying Spaghetti Monster [venganza.org] might have used His Noodly Appendage to intelligently design it that way. Scientists speculate the arrangement makes it easier for Him to make a bank shot on the 9-ball galaxy.

  • Right. (Score:5, Funny)

    by balloot (943499) on Sunday January 15 2006, @06:42PM (#14478170)
    Am I the only one who thinks this headline sounds like something some scientist completely pulled out of his ass? "Yeah...so you know dark matter? All the planets are, like, floating on it. And I am TOTALLY stoned...."
    • Wait, I've seen this episode of Star Trek. We have to get two dimensional!
    • Oh yes, exactly! And did you know that if you accelerate and I do the same in different direction, and a tree falls somewhere between us we'll never agree at which time it happened? It's totally out there...

      I'm not saying the Styx thing is true, only that eventually, time will tell. And if it doesn't prove to be true now, it's maybe because current instruments are too crude to prove it yet. As someone one said, reality is SO much more weirder than fantasy.

  • a name for it (Score:5, Interesting)

    by heatdeath (217147) on Sunday January 15 2006, @06:56PM (#14478238)
    If they eventually find more evidence for these "dark matter streams", and start naming them, I think "the styx" would be a completely awesome name for such a stream.

  • Old Lady (Score:5, Funny)

    by nacturation (646836) <nacturation@gmail. c o m> on Sunday January 15 2006, @09:00PM (#14478809) Journal
    Galaxies Floating on a Dark Matter Stream

    So, the old lady was right... it's turtles all the way down.
     

  • Occam's Razor Please (Score:4, Insightful)

    by fygment (444210) on Sunday January 15 2006, @09:41PM (#14478986)
    So we have two theories:

    a) dark matter filaments (modeled on a computer no less). Matter we cannot see; who's existence is contentious, etc.

    b) the remnants of a cannibalized galaxy. Solid evidence of this principle abundantly available.

    Why leap to the more complicated and, arguably esoteric, explanation?

  • Dark Matter bullshit, admit scientists (Score:5, Funny)

    by Snafoo (38566) on Sunday January 15 2006, @09:43PM (#14478992)
    AP - Scientists at the prestigious CERN institute in Switzerland announced late Friday that the so-called 'dark matter', which makes up 90% of the universe, is actually bullshit.
    "These findings come as a surprise," stated Dr. Weissmann, lead scientist at the institute. "Before today, we thought dark matter might be, say, an agglomeration of exotic subatomic particles, like muons or 'strange' quarks, signifying a problem with the equations governing space-time. Instead, all that turns out to be bullshit."
    Other hypotheses included Cheez-puffs and intelligent end-users. But the conclusive evidence for the new Bullshit Theory of Matter came from the Hubble space telescope, which since 1995 has been sending back data that, according to scientists, is "complete and utter bull."
    "Over and over we ran through the equations, and each time we came up with the same answer: This is crap," affirmed Weismann. "It's satisfying, in a way, to be able to say that about your life's work."

    -C.
  • I've heard Dr. Michio Kaku theorize that dark matter is the gravitational effect of the matter of other universes that are close to ours. I found that to be an intriguing thought, bringing two pretty wild ideas, dark matter and multiple universes, together in a coherent and even intuitive way.

    ahref=http://www.mkaku.org/rel=url2html-18972 [slashdot.org]http: //www.mkaku.org/>

    • "North Korea is making far bigger noises about making their own nuclear bombs, but no one seems to make such a fuss ...."

      [OT, Sorry.]

      Um, yeah, that's because several countries have diplomatic relations with NK and are negotiating with them. The US is actually doing the right thing here (or at least what everybody wanted them to do with regards to Iraq), but nobody wants to acknowledge that because of the monkey in the White House.
        • That, and the fact it we don't want to be fighting wars on two different fronts. Chances are, we will deal with N. Korea with military means once we are sure Europe can take on Iran. It's WWIII, I'm bloddy serious.

          That is so utterly wrong I can't even begin to put words to it. The US will never ever deal with North Korea militarily unless North Korea attacks another nation.

          People forget that the capital of South Korea is in artillery range of North Korea. North Korea has a massive amount of chemical and b

    • In his zeal to take a political potshot Zonk has ignored the most recent developments. Don't be deceived. NASA administrator Michael Griffin has reconsidered [spacedaily.com] earlier the earlier decision to scrap Hubble servicing. A shuttle crew will indeed have to risk their lives to extend Hubble's life for a few more years. Relax. There should still be lots of money left over to invest in Iraqi freedom, and to kill Al Qaida.

        • Or first US city: China would be more than happy to provide North Korea with a Dong Feng 31 or two and Kim already has the payload. That is if Kim doesn't get his Taepodong-2s up and running. Seattle is well within range.

    • Well let's see, NASA administrator Sean O'Keefe says it will never be visited by a space shuttle repair mission again, which means it will be history as soon as its batteries or gyroscope fails within the next few years, despite repeated efforts by concerned groups to keep it up and running. I'd call that effectively decommissioned.

      From the BBC [bbc.co.uk]after NASA's 2006 budget announcement (in February 2005)...

      • Re:Hubble Space Telescope (Score:5, Informative)

        by wass (72082) on Sunday January 15 2006, @06:54PM (#14478229)
        Well let's see, NASA administrator Sean O'Keefe says it will never be visited by a space shuttle repair mission again

        Um dude, O'Keefe has been gone from NASA for nine months now, your article link is almost a year old. One of the first things that the new administrator Michael Griffin did when he took over the reins was to try to figure out ways to keep Hubble alive. Griffin's an actual scientist, unlike O'Keefe who's a career-track manager. And thus sees the important of Hubble, which has been indispensible for astronomical research.

        Direct from NASA's Hubble page [nasa.gov], it says

        "At his April, 2005 confirmation hearing before the U.S. Senate, as well as in subsequent statements, new NASA Administrator Michael D. Griffin testified to the extraordinary scientific value of Hubble. He indicated his desire to take the robotic servicing mission "off the plate" on the basis of mission complexity, and reconsider an SM4 Shuttle-astronaut mission to Hubble. His rationale is that after the Shuttle's Return to Flight ("RTF", currently scheduled for July of 2005), and in particular after all the Shuttle improvements that precede RTF, NASA will essentially have a "new" Shuttle vehicle and system in the context of astronaut and mission safety. After successes in RTF and the following flight, if analysis shows that the risk levels associated with a Hubble mission are sufficiently low and manageable, SM4 could be reinstated by the Administrator."

        • your article link is almost a year old

          I even noted that in my post, to pre-emptively head off any nitpicking. Looking at the page you link to, I see no concrete plans. I see "if", I see "possibility", I see "could", and I see "might". Nothing that says, yes, we will repair Hubble in the mission scheduled for such and such a date. I'm all for a continuance of Hubble service; I just don't see it happening.

          O'Keefe has been gone from NASA for nine months now

          Yup, I should have said "said", not says. Me

          • My whole point is that the O'Keefe style of management, namely cutting important science missions in the name of 'safety', is changing. Especially since the Columbia accident happened on O'Keefe's watch, while Griffin comes in with a clean record.
    • Using images from the Hubble space telescope, soon to be decommissioned...

      Do you know something that NASA and us astronomers don't?

      Talking to yourself?

    • > Matter = Stuff Anti-Matter = Stuff that blows stuff up Dark Matter = The stuff that isn't there, that we keep bumping into

      To paraphrase the old saw about virtual memory:

      If you can see it and it's there, it's matter.
      If you can see it and it's not there, it's a virtual particle.
      If you can't see it and it's there, it's dark matter.
      If you can't see it and it's not there, it's dark energy.

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