back to article Phew, galactic accident helps boffins explain dark matter riddle

An accidental discovery by a team of astronomers has helped answer one of the burning questions about dark matter and where it came from. Previous studies found that galaxies created over ten billion years ago contained low levels of dark matter. This posed the annoying question of where it all came from since then, as dark …

  1. Spherical Cow

    Where is Moon Child?

    The idea that the amount of dark matter is increasing with time kind of reminds me of The Nothing in The Never-Ending Story.

    (I didn't get around to finishing that book, so it lived up to its name)

    1. Anonymous Coward
      Anonymous Coward

      Re: Where is Moon Child?

      "I didn't get around to finishing that book, so it lived up to its name"

      They made a mistake and added an ending to the film. That's why they had to make "The Neverending Story Part 2".

      I'm still waiting for part 3...

      1. gimpySue

        Re: Where is Moon Child?

        Actually there is a part 3.

        In my opinion, it sucked, don't bother with it. But here you go:

        https://www.imdb.com/title/tt0110647/

  2. Neil Barnes Silver badge
    Coat

    Surely it's easy?

    Ancient galaxies have less dark matter, new galaxies have more. But when we see an ancient galaxy, we see it a long long time ago, when it was actually young.

    Obviously, dark matter is just stars that have worn out.

    I'll need the coat for the Nobel Prize, thanks -->

    1. Spherical Cow

      Re: Surely it's easy?

      Flat batteries, probably. I have the same trouble with my torch.

    2. tfb Silver badge

      Re: Surely it's easy?

      That's close enough to the MACHO theory I think that it can be ruled out for the same reasons: if there were lots or dead stars we would observe them through gravitational microlensing events, and we don't see enough of those.

      1. Neil Barnes Silver badge

        Re: Surely it's easy?

        I seem to have upset a lot of astrophysicists - anyone care to explain why? Or was the coat not indication enough that I wasn't being serious?

        1. Florida1920 Silver badge

          Re: Surely it's easy?

          @Neil Barnes

          I seem to have upset a lot of astrophysicists - anyone care to explain why? Or was the coat not indication enough that I wasn't being serious?
          It must be seasonal. The literalists have been coming out of the woodwork lately.

        2. tfb Silver badge

          Re: Surely it's easy?

          You didn't upset me, I realised it was a joke! But it's also an interesting idea which is why I answered.

    3. I ain't Spartacus Gold badge
      Pint

      Re: Surely it's easy?

      Neil Barnes,

      I think you're utterly wrong. Though I didn't downvote you.

      I think you'll find that dark matter isn't there in young galaxies because they're footloose and fancy free. It's when they start to age, that all the existential dread comes in, from children mortgages, fear of impending doom etc. Thus dark matter = existential dread.

      I'll take my Nobel grant in beer thanks.

      1. tfb Silver badge

        Re: Surely it's easy?

        Basically it's depressed galaxies. I like this theory.

        1. Ugotta B. Kiddingme

          Re: Basically it's depressed galaxies

          Do these galaxies have a pain in the diodes stars down their left side? Has a certain "plastic pal who's fun to be with"©®™ visited there?

          1. tfb Silver badge

            Re: Basically it's depressed galaxies

            I think they, being galaxies and all, know the answer to the Fermi paradox: it is, pretty much, just us. And they're watching us commit suicide as a species: who wouldn't be depressed?

            (Please don't pick me up on the causal impossibility of this...)

        2. mosw

          Re: Surely it's easy?

          > Basically it's depressed galaxies. I like this theory.

          Or a paranoid android with a brain the size of a galaxy.

          Marvin

      2. Fruit and Nutcase Silver badge
        Pint

        Re: Surely it's easy?

        @I ain't Spartacus

        I'll take my Nobel grant in beer thanks.

        I thought the dark stuff originates from St. James's Gate in Dublin?

        1. I ain't Spartacus Gold badge

          Re: Surely it's easy?

          I think Dublin is just an over-priced visitors' centre nowadays - and it's actually made in Cork.

          Although perhaps they know something about cosmology that the rest of us don't?

          In which case, do Guinness manufacture the dark matter, or is Guinness just made out of it? And given the post-Guinness black poo issue, have we found an area where dark matter directly interacts with normal matter? [Insert your own joke about dropping heavy particles here...]

  3. herman Silver badge

    Now we know where the Grues are

    It is pitch black. You are in danger of being eaten by a... Chomp!

  4. redpawn Silver badge

    If

    we reverse the polarity in the CCD array the dark will momentarily become light and be easily seen. This works well in the movies and science imitates science fiction.

    1. David Shaw

      Re: If

      (I do actually test full 330 watt bi-facial PV modules this way) feed in rather a lot of amps& volts; they glow, a bit, mostly IR, but can be photographed and reveal amorphous or crystalline silicon defects.

      Not sure if reverse electroluminescence of a CCD would illuminate much dark-matter, or remote galaxies, but worth a try.

  5. sorry, what?
    Stop

    Explains the riddle...?

    I think not.

    1. Richard Boyce

      Re: Explains the riddle...?

      At best, it just seems to modify the existing riddle. Why do most old galaxies have little dark matter?

      We still don't know what dark matter is.

      1. ivan5

        Re: Explains the riddle...?

        <i.We still don't know what dark matter is.</i>

        Or even if it exists as a substance.

        1. Version 1.0 Silver badge

          Re: Explains the riddle...?

          I think it does exist, it's caused by a strong Brownian Motion (say a nice hot cup of tea) in another dimension - Hitchhiker's Guide to the Galaxy

      2. Andy The Hat Silver badge

        Re: Explains the riddle...?

        Exactly, isn't this just one aberrant point on the graph - the reading that would normally be regarded as unreliable in a pool of consistency?

        Cups of tea are hot. My cup of tea is demonstrably cold. Therefore all cups of tea are cold and all previously measured cups must have been cold...

        I would suggest the conclusions as reported are 'excessively optimistic'.

        1. Kleykenb

          Re: Explains the riddle...?

          "What did you expect?"

          ...

          A Schweppes add? ;-)

          1. Killfalcon Silver badge

            Re: Explains the riddle...?

            I *think* what they mean is that this is the first old galaxy we've been able to measure in this way (because of the angle), and previous results suggesting low levels of dark matter in old galaxies were using less precise methods (at a guess that'd be something like gravitational lensing, the rotation at the outer edges only, or trying to infer the effects on nearby galaxies).

            1. Andy The Hat Silver badge

              Re: Explains the riddle...?

              You may be correct that Accuracy and method may be different but one of the earlier investigations was 240 disks not just the one and they did have the accuracy to measure angular velocity at various radii ... I still think there's more work needed to prove the conclusion based on only one observation.

        2. Doctor Syntax Silver badge

          Re: Explains the riddle...?

          "Exactly, isn't this just one aberrant point on the graph"

          An entire galaxy is a pretty big point.

          1. John Brown (no body) Silver badge

            Re: Explains the riddle...?

            "An entire galaxy is a pretty big point."

            Even an entire galaxy is just a Mote in the Universes Eye.

    2. Sceptic Tank
      Paris Hilton

      Re: Explains the riddle...?

      I was also wondering if I missed the part of the riddle being explained. Seems to me like the absent dark matter in all the other old galaxies is still unexplained.

  6. Pascal Monett Silver badge
    Unhappy

    Misleading title

    I opened this article thinking that scientists had finally explained dark matter.

    Not at all, they just found an old galaxy with present-day amounts of the stuff.

    All well and good, and now it must be asked what measurement error made us misinterpret the data on all the other old galaxies, but this does nothing to explain dark matter.

    1. Anonymous Coward Silver badge
      Boffin

      Re: Misleading title

      I'll explain dark matter for you then. It is matter, that's dark.

      Happy?

      1. Andy The Hat Silver badge

        Re: Misleading title

        ... or it's not matter as we know it and it's not dark :-)

        It's actually God's finger pushing stuff about :-)

        1. Semtex451 Silver badge

          Re: Misleading title

          It is.

          Its the FSM's noodly tendrils, I've been saying this all day.

      2. cynic56

        Re: Misleading title

        No. Not until you define 'dark'

  7. digga

    To be young again

    Our galaxy is one of the younger ones?

    We have stars that are almost as old as the universe.

    A quick google tells me our galaxy is a mere 300 million years younger than the universe and if the big bang theory is correct, part of the first 300 million years were the dark days of massive inflation.

    1. Lars Silver badge
      Coat

      Re: To be young again

      In astronomy it's so easy, young or old, to drop a bunch of zeroes in front of the decimal point. Right.

    2. tfb Silver badge
      Boffin

      Re: To be young again

      Well 'part of the first 300 million years' means 'from 10E-36 to about 10E-32 seconds after the big bang' so ... quite a small part.

      What you might mean is the surface of last scattering, which is the point where the universe got cool enough for light to propagate -- when it was cool enough for electrons and protons to combine into Hydrogen in other words. This is what we're looking at when we look at the CMB, and it's about 380,000 years after the big bang.

  8. Sceptic Tank
    Angel

    A long time ago ...

    I'm amazed that the words "a galaxy *created* about 9.6 billion years ago" has not resulted in 9.7 billion pages of anti-creationist commentary yet. The topic must be getting old.

  9. Michael H.F. Wilkinson Silver badge
    Joke

    And there I was thinking ...

    "Galactic Accident" in the title referred to a cosmic prang seen all too often when those in charge of galaxies fail to watch where they are going. Really, really, really! You put them in charge of a galaxy and they think they are rulers of the universe!

    1. I ain't Spartacus Gold badge

      Re: And there I was thinking ...

      The problem is these modern self-driving galaxies that people insist on testing out on the public space-time continuum.

      They're dangerous. At this rate we'll have to build more hyperspace bypasses.

  10. CommanderGalaxian
    Alien

    Lexx

    Dark Matter is simple - it's Mantrid's Drones.

  11. Ima Ballsy
    Facepalm

    Not Found ....

    I Left some DARK MATTER for them to find this morning.

    Sadly, the missus made me flush the loo ....

    1. Semtex451 Silver badge
      Windows

      Re: Not Found ....

      Dat'll be da Guinness ;\

  12. David Nash Silver badge

    Negative Mass

    Apparently:

    https://cosmosmagazine.com/space/could-negative-mass-unify-dark-matter-dark-energy

    1. fandom Silver badge

      Re: Negative Mass

      All those jokes comparing dark matter to phlogiston and some serious boffins go on and say 'you know what, it is phlogiston!

  13. Anonymous Coward
    Anonymous Coward

    One is not like the others...

    “The galaxy we found is a clear counter-example of that, where it seems to have dark matter behaving in the normal way, as it does in the present-day universe.”

    As I understand it, current theories of galaxy formation need dark matter in the primordial mix to work well, but the earlier studies found DM was lacking in the first three billenia, and this fact is vexxing. The theory has a big hole in it.

    Now someone has found a galaxy, almost old enough to be classed in that era, that has plenty of DM. That's very interesting, but how does this discovery negate the problem presented by the other old galaxies they found lacking DM? The article seems to imply this find fixes the DM theory problem, but does it really?

  14. Anonymous Coward
    Anonymous Coward

    does it matter

    Is it dark matter? Really? We've still to capture or measure any. It sounds like we have come all the way back to the concept of Aether. And that was just a name for "we don't know how the **** this happens". Giving it a new millenial name doesn't change what it is.

    Perhaps its just our poor monkey brains trying to make sense of an Ndimensional universe through a 4d set of goggles.

    Can we just call it Magic and have done?

    1. tfb Silver badge
      Boffin

      Re: does it matter

      It's different than aether, because while we have no idea what it is we can detect it. So, yes, we can measure it: we can look at galactic rotation curves and infer from them how much dark matter must be there. This is essentially the same trick we did to discover Neptune and Pluto: look at some stuff we can see, infer things about the gravitational field from their motion and infer there must be some other thing we can't see. Of course, in the case of Neptune & Pluto we did see them when we looked hard enough. The trouble with aether was that it turned out that there was no way to detect it even in principle, and some smart guy decided that things which you could not detect, even in principle, were not there. He did this trick several times with different things: it's a good trick.

  15. 89724102172714182892114I7551670349743096734346773478647892349863592355648544996312855148587659264921
  16. Wincerind
    Coat

    The Matrix?

    How about this.

    The Universe is a simulation a bit like The Matrix. The increased Dark Matter in the newer galaxies is because they're running over budget and they're short of hard drive space. Gaps in the simulation which manifests itself as "Dark Matter".

    1. Danny 2 Silver badge

      Re: The Matrix?

      "The Universe is a simulation a bit like The Matrix."

      So there are sequel universes, each one worse than it's predecessor and without any stars?

      1. Wincerind

        Re: The Matrix?

        Or possibly like in the film "the Thirteenth Floor" where simulations are nested within simulations.

  17. Paul J Turner

    Dark Matter is a joke

    Galaxies rotate slower at the outside than nearer the centre, It's obviously a wind-up.

  18. Ken Moorhouse Silver badge

    Keck Telescope

    Do they zip it up when they aren't using it?

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