Slashdot Mirror


Half the Universe's Missing Matter Has Just Been Finally Found (newscientist.com)

An anonymous reader shares a report: The missing links between galaxies have finally been found. This is the first detection of the roughly half of the normal matter in our universe -- protons, neutrons and electrons -- unaccounted for by previous observations of stars, galaxies and other bright objects in space. You have probably heard about the hunt for dark matter, a mysterious substance thought to permeate the universe, the effects of which we can see through its gravitational pull. But our models of the universe also say there should be about twice as much ordinary matter out there, compared with what we have observed so far. Two separate teams found the missing matter -- made of particles called baryons rather than dark matter -- linking galaxies together through filaments of hot, diffuse gas. "The missing baryon problem is solved," says Hideki Tanimura at the Institute of Space Astrophysics in Orsay, France, leader of one of the groups. The other team was led by Anna de Graaff at the University of Edinburgh, UK. Because the gas is so tenuous and not quite hot enough for X-ray telescopes to pick up, nobody had been able to see it before.

8 of 247 comments (clear)

  1. Re:Dark matter by fahrbot-bot · · Score: 5, Informative

    I've been saying for years that "dark matter" and "dark energy" aren't really things. They're placeholders for some type of matter or interaction we'll discover later.

    That we're finally able to detect these baryon filaments is a solid step in the right direction to finally solving the "dark" mystery.

    Not quite. TFA and TFS say that Dark Matter exists *and* they just found the missing "regular" matter. (highlighting mine):

    You have probably heard about the hunt for dark matter, a mysterious substance thought to permeate the universe, the effects of which we can see through its gravitational pull.

    But our models of the universe also say there should be about twice as much ordinary matter out there, compared with what we have observed so far.

    --
    It must have been something you assimilated. . . .
  2. Summary is wrong - not about dark matter by FeelGood314 · · Score: 4, Informative

    They found some of the missing baryon matter. This is the normal matter that is around us every day. Dark matter is stuff that has momentum and exerts a gravitational field but doesn't interact electromagnetically, so we can't see it. We believe most of the matter in the universe is dark matter but we also believe there is a lot more of the normal baryon matter out there but we just don't know where or what it is. These studies have shown that there are filaments of hot gas stretching between galaxies. The density of this gas is extremely low but the volume it occupies is huge so it contributes to a large amount of the baryon matter in the universe.

    1. Re:Summary is wrong - not about dark matter by EvilSS · · Score: 4, Informative

      Summary never said it was about dark matter. It's clearly talking about the missing baryon matter.

      --
      I browse on +1 so AC's need not respond, I won't see it.
    2. Re:Summary is wrong - not about dark matter by EvilSS · · Score: 4, Informative

      Dark matter was/is the explanation for the missing regular matter. Less missing regular matter, less dark matter.

      The only data for dark matter is gravitational lensing in excess of what was accounted for by the previously known regular matter. All those numbers need to get run again in light of this discovery.

      Science reporting sucks.

      We suspect a certain amount of normal matter, and a certain amount of dark matter in the universe. All this study did was help confirm that we were right about the amount of normal matter out there. It has no effect, at all, on the amount of dark matter science thinks is out there as well. It didn't shift the totals one bit.

      --
      I browse on +1 so AC's need not respond, I won't see it.
  3. Re:Dark matter by EvilSS · · Score: 4, Informative
    I mean, did you even bother to read the summary?

    This is the first detection of the roughly half of the normal matter in our universe -- protons, neutrons and electrons -- unaccounted for by previous observations of stars, galaxies and other bright objects in space. You have probably heard about the hunt for dark matter, a mysterious substance thought to permeate the universe, the effects of which we can see through its gravitational pull. But our models of the universe also say there should be about twice as much ordinary matter out there, compared with what we have observed so far.

    This paper is talking about the missing non-dark matter that the current models said should be there. I had nothing to do with dark matter, and the matter they found has no impact on the expected amount of dark matter in the universe.

    --
    I browse on +1 so AC's need not respond, I won't see it.
  4. Re:The simplest answer is often the correct one. by skoskav · · Score: 4, Informative

    Completely agree with you - Occam's Razor Wins Again...

    That's a butchering of Occam's Razor. The law is about preferring the most parsimonious hypothesis, i.e. the one that makes the fewest assumptions.

    Dark matter being composed of a diffuse gas of standard baryonic matter could be the simplest hypothesis, but it makes many assumptions by implicitly refuting consolidating evidence against it. Wikipedia lists a few of them: https://en.wikipedia.org/wiki/...

  5. Re: Dark matter by orlanz · · Score: 4, Informative

    You should really read the article. This isn't two independent groups scanning and suddenly discovering new pieces of the universe. It's basically a common data aggregating process applied to massive amounts of data to brighten faint emissions. Considering every star gazer with $5000 worth of equipment and a Mac does this every week, how many papers does that need to prove itself?

    Of course the next step is to test it across more spots in the universe to hopefully find anomolies.

  6. Re:Dark matter by Falconnan · · Score: 4, Informative

    Apologies, but almost all of this is wrong.

    Models based on observations indicated that 4% of the universe's mas/energy composition had to be normal, baryonic matter. Half of that 4% was missing until today. Dark matter, based on observations, needs to be approximately 23% of the mass of the universe. Otherwise galaxies would not have formed and would spin apart. Further, most of the mass of dark matter is associated with galaxies, and this matter was found between them. Details "matter" (unless of course they "energy").