back to article Dark matter drought hits older galaxies: Boffins are, rightly, baffled

The mystery surrounding dark matter deepens: scientists have discovered that the puzzling substance was less dominant in our universe's early galaxies. Although no one knows what dark matter is made out of, physicists generally agree that it exists, and that it can be observed albeit indirectly. In the 1970s, astronomers …

  1. Version 1.0 Silver badge

    Does dark matter?

    Maybe they are finally on the track of proton decay?

    1. Destroy All Monsters Silver badge

      Re: Does dark matter?

      Protons don't decay.

      At least not over any reasonable count of universe lifetimes.

      1. This post has been deleted by a moderator

  2. Your alien overlord - fear me
    Headmaster

    Scientists get their maths wrong and so rather admit it, they make up dark matter. If only I'd known I could do that back in my school days !!!

    1. Lars Silver badge
      Joke

      "If only I'd known I could do that back in my school days !!!". I am sure you did.

    2. Big John Silver badge

      Most of physics and cosmology involve performing observations and then trying to develop a mathematical model (tied to known laws of physics) that matches those observations. Then the model is examined for clues that could predict future observations. If such predictions are proved, it gives a big boost to the model and the theory behind it.

      The early galactic models were predicated on the assumption that what we saw was what we got. Then what we saw failed to match the model and so it was discarded for another that includes extra mass we can't see.

      The new model matches the observations, but it doesn't indicate the nature of the mass. No one got any maths "wrong" and in fact the cosmologists were quite pleased that the old model was wrong, because that makes their job much more interesting.

      1. a_yank_lurker Silver badge

        @ Big John, To me dark matter and dark energy point to a fundamental problem with our theories much like the situation in theoretical physics at about 1900. My nagging suspicion is more based on the fact that neither can be observed.

        1. Big John Silver badge

          Something is making the galaxies spin wrong. Either it's a whole lot of extra mass/energy at the edges of galactic disks, or it's because we are missing something major about gravity itself. It can't be denied that no well accepted theory of Quantum Gravity currently exists, and there has to be one or the rest of physics is going to hear about it, very loudly. So there's room yet for weird changes to our perception of reality.

          Say, perhaps dark matter is really just a build up of 'tired gravitons' around the galactic disks? That would explain the increasing effect over time... :-D

          1. DougS Silver badge

            Or it could be that dark matter is created through some process we don't yet understand. Maybe supernovas create it, or stars themselves radiate it along with photons and neutrinos.

          2. David Nash Silver badge

            galaxies spin wrong

            Not "wrong". Just different than expected, based on observations so far.

        2. Anonymous Coward
          Anonymous Coward

          @a_yank_lurker, Maybe they could even go back and re look at the old aether theory which appears to fit the facts they are observing.

        3. LionelB

          @a_yank_lurker

          You may well turn out to be correct, but the fact that neither dark matter nor dark energy can be (currently) observed does not necessarily point to that conclusion. Many, many phenomena in physics were predicted long before they could be detected (gravitational waves, as predicted by general relativity, being a recent example).

          1. sabroni Silver badge

            re: Many, many phenomena in physics were predicted long before they could be detected

            Indeed, that is how science works. Nevertheless, before the proof is concrete it's sensible to take the theory with a pinch of salt.

            It does look like a bodge though. Calling it "amending the model to fit the data" sounds better as long as you don't think about it for too long.

            1. TitterYeNot

              Re: re: Many, many phenomena in physics were predicted long before they could be detected

              "Indeed, that is how science works. Nevertheless, before the proof is concrete it's sensible to take the theory with a pinch of salt."

              Not quite. As I understand it, the only place concrete proof exists is in pure mathematics (i.e. proving a mathematical statement.) Scientific theories i.e. Einstein's theory of gravity, are impossible to absolutely prove, they just become more accepted as valid as more evidence is found to support them. A theory can be fully or partially disproved in an instant, however, if a prediction that is made as part of said theory is shown to be incorrect. All the science we 'know', is 'just a theory', but some of it has been around so long without being disproved that it is accepted as fact.

              You're absolutely right that theories without evidence are taken with a pinch of salt. Peter Higgs (and his team) proposed the Higgs mechanism back in 1964, but didn't receive acceptance of his theory (and the Nobel prize that went with it) until 2013, after the Higgs boson had finally been detected in a two Large Hadron Collider experiments.

              And other commentards seem to missing the point when talking about 'scientists getting their maths wrong so making things up.' Science and its theories evolve as our knowledge expands. Newtonian theory works absolutely fine here down on Earth when you're looking at falling apples, moving carriages and spheres dropped from towers. At the scale of the solar system, however, it starts to break down, its predictions in some cases not matching what we observe i.e. Mercury's orbit. Then along comes Einstein, and his description of gravity in the theory of general relativity offers a major refinement of Newtonian mechanics, and matches the motion we see in the solar system exactly.

              Then as our view moves ever outwards to study the motion of distant spiral galaxies, we see that again, the currently accepted theory doesn't quite seem to fit what we observe. Either Einstein's theory of gravity is not quite correct, or there is more mass present than we can observe using our current technological capabilities, or possibly both. Given time, I imagine and hope a unified theory of gravity will emerge, and we'll understand gravity to be either a subsequence of the bending of space-time around mass, or the result of the interactions of the gravitons predicted by some quantum mechanics theories, and then we'll have a better understanding of whether the existence of dark matter is needed to explain galactic rotation.

            2. Michael H.F. Wilkinson Silver badge

              Re: re: Many, many phenomena in physics were predicted long before they could be detected

              It does look like a bodge though. Calling it "amending the model to fit the data" sounds better as long as you don't think about it for too long.

              Better than amending the data to fit the model, isn't it? The cyclic process of observation/experiment -> derive theories that explain the observation/experiment -> design observations/experiments that can falsify the theory -> back to step one, means that as we develop and refine theories, they evolve into forms that explain more and more. For example, Newtonian gravity explained far more than Plato's or Aristotle's idea of gravity, which was essentially separate from their model of planetary motion. Newton unified it, and explained the elliptical, rather than circular orbits put forward by Kepler. What it couldn't explain was the precession of the perihelion of Mercury. Einstein's general relativity put forward a single framework that explained both Mercury's odd, and the other more regular orbits, plus a whole lot more.

              Replacing general relativity may well be called for to rid ourselves of dark matter/energy, but at the same time the replacement must explain all previous stuff as well.

        4. Toni the terrible
          Alert

          Holy Dust!

          His Dark Material?

        5. Jeffrey Nonken Silver badge

          Gravity can't be observed, either. We deduce its characteristics by its effects.

    3. LionelB

      Scientists get their maths wrong and so rather admit it, they make up dark matter.

      Meanwhile back in the real world, scientists get their models wrong (because they're mortals working with limited information), admit it, and amend their models.

  3. adam 40

    Fractal, innit?

    "Normal" matter seems to be distributed fractally all the way through from planets, solar systems, star clusters, galaxies, galaxy clusters, etc.

    Why wouldn't the same be true of dark matter? Why would dark matter have to coincide with every galaxy equally?

    Seems that we are just observing what's out there.

    1. P. Lee Silver badge

      Re: Fractal, innit?

      >"Normal" matter seems to be distributed fractally all the way through from planets, solar systems, star clusters, galaxies, galaxy clusters, etc.

      Not just those. Spiral galaxies, sea-shells, bodies, faces, sunflower seeds, bird flight patterns, fingers and hurricanes all made with mathematical precision around a single ratio.

      http://io9.gizmodo.com/5985588/15-uncanny-examples-of-the-golden-ratio-in-nature

      Of course the universe doesn't have consistent design principles. It just looks like it does.

  4. Hasham

    Am I right in thinking...

    That the light from those old galaxies shows their dark matter situation billions of years ago, and the shape of those galaxies and their dark matter situation today would be very different? Perhaps gravity has an effect on space-time that intensifies as the years go by?

    1. Big John Silver badge

      Re: Am I right in thinking...

      Or maybe it took time for the galaxies to 'collect' dark matter. It does seem to be something exotic, so exotic behavior might be expected.

      1. Long John Brass Silver badge

        Re: Am I right in thinking...

        @Big John

        Collect, or perhaps manufacture. If Dark Matter is a by product a stellar process then as the universe and the galaxies within ages; we will see more of it?

        1. Meph
          Thumb Up

          Re: Am I right in thinking...

          @Long John Brass

          | Collect, or perhaps manufacture.

          Possibly even "distribute". It may take some time over the life of the galaxy to displace dark matter from the galactic core and concentrate it at the edges in enough density to cause the observed effects.

    2. Rich 11 Silver badge

      Re: Am I right in thinking...

      and the shape of those galaxies and their dark matter situation today would be very different

      Almost certainly. We only have to wait a few billion years to find out. In the meantime, though, we can look at closer galaxies and get a better idea.

      Perhaps gravity has an effect on space-time that intensifies as the years go by?

      Let's call this the 'inverse knackered elastic band' effect. But since gravity is actually what we call the effect of mass on space-time, you probably don't need to piss around inverting elastic bands...

    3. Jtom Bronze badge

      Re: Am I right in thinking...

      Instead of inventing new (dark) matter to make models and observations line up, I think they need to re-evaluate their assumptions. Their number one assumption is that the gravitational constant is invariant over time and space. Perhaps it isn't (which essentially becomes your idea).

      We have absolutely no reason to believe that constants in physics are truly constants in all of time and over all of space. Perhaps the problems with dark matter is evidence that they are not.

  5. Richard 12 Silver badge

    It's from before the photino birds evolved

    Obvious, right?

  6. Anonymous Coward
    Anonymous Coward

    Dark or light, up or down, positive or negative, alternating current.

    Maybe life, the universe and everything works in a different way to what we think.

    Circles, spirals, no end or beginning, apply it to science and you could have some interesting theories that could be proved or disproved.

    1. Rich 11 Silver badge

      You've had a really good night in the pub, haven't you?

      1. Anonymous Coward
        Anonymous Coward

        @Rich 11

        Spot on. Maybe left field thinking may surprise us with new science. I don't know, I just like to try and think differently sometimes.

    2. Anonymous Coward
      Anonymous Coward

      Universe

      as designed by Thomas Crown

  7. thomas k

    So,Tesla was right after all?

    "Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality."

    1. LionelB

      Re: So,Tesla was right after all?

      Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality.

      Which is pretty much what Albert Einstein (a contemporary of Tesla) did in his development of general relativity. Except that his "structure" turned out to have a pretty damn strong relation to reality.

  8. Anonymous Coward
    Anonymous Coward

    Natascha Förster Schreiber

    I'm just impressed by her name!

  9. Schultz
    Boffin

    Neutron dust

    Here is my suggestion: Dark matter is neutron dust.

    Think about it as ground-up neutron stars. Maybe it's formed in galaxy collisions, or maybe it's a leftover from the Big Bang. Why this neutron dust doesn't aggregate into neutron clumps, you ask? Dark energy of course! The mystery force obviously repels those neutron particles and all the other matter in the observed universe.

    Next question please ....

    1. EBG

      Next Question ?

      HTF are you going to "grind up" a neutron star, given that it's the most tighty gravitiationally bound class of object in the universe after a black hole ?

      1. Schultz

        HTF are you going to "grind up" a neutron star

        Smash two of them together? Fly it past the edges of a black hole? Us the Big Peppercorn Grinder the Flying Spaghetti Monster uses to spice up its noodly appendages?

  10. ChrisPv

    Ether of the 20/21st century physics

    I always believed that dark matter is for current physics what Ether was for XIX century one. I.e way to explain observable results differing from current theory, using framework of the current theory. We need new theory, in my very very humble opinion.

  11. carlfailmezger

    Dark is Imaginary. Big Bang incorrect. WhiteHoleTheory.com

    Dark Matter and Dark Energy are non-existent and imagined only to pretend that the Big Bang Theory is correct. When Observations and scientific law conflict with theory, good science questions theory rather than changing the observed facts. Keppler Laws and our observations are correct: rotating galaxies are expanding (No Dark Matter). Galaxies with very high linear velocities do not need "Dark Energy"; they accelerated when they were small and grew larger after achieving high velocity. Galaxies formed from matter which was created gradually by their central white holes. For correct understanding of galaxy formation: see WhiteHoleTheory.com

    1. Yugguy

      Re: Dark is Imaginary. Big Bang incorrect. WhiteHoleTheory.com

      1995 called, it wants its website back.

    2. David Nash Silver badge

      Re: Dark is Imaginary. Big Bang incorrect. WhiteHoleTheory.com

      "When Observations and scientific law conflict with theory, good science questions theory rather than changing the observed facts."

      As far as I can tell, that's exactly what this story is about.

  12. Destroy All Monsters Silver badge
    Windows

    Head over to nautil.us mag for a pretty good layman-level overview of dark matter explain-away-ery and explanations of MOND.

    http://cosmos.nautil.us/

    I like it when observation drives physics. Compare with the sterile multiverse crap, where grants drives physics.

    1. Doctor Syntax Silver badge

      "http://cosmos.nautil.us/"

      Wonderful site! Displays SFA except header & footer without allowing javascript. Am I going to enable javascript for it? No.

      1. Destroy All Monsters Silver badge

        I commend your stuckism but ... welcome to 2017 Internet.

        Still not running in VMs?

    2. Paul Kinsler

      "where grants drives physics"

      You do know we only want the grants so we can do more physics, don't you.

    3. LionelB

      @Destroy All Monsters

      Fascinating article, but I came away with the impression that MOND theories are at least (if not more) speculative than Dark Matter/Energy theories. Nor, judging by that article, does MOND come across as more data-driven than DM/DE. There is, of course, bound to be resistance to MOND on the grounds that it breaks General Relativity (but then again perhaps General Relativity needs to be broken).

      Guess we'll have to wait and see if either approach has legs.

      Also, is there really that much grant-related mileage in multiverse theories? They seem to represent, perhaps, more a philosophic than scientific standpoint. From the point of view of science they may well be, as you say, "sterile crap", in the sense that they are not "useful" - they don't seem to make verifiable predictions beyond standard quantum theory. From a philosophical viewpoint, though, they do seem to furnish infuriatingly consistent interpretations for the crazee world of quantum phenomena - where even more traditional interpretations stretch intuition beyond breaking-point.

  13. Complicated Disaster

    But what if?

    The other possibility that would explain the observations, of course, is that the laws of physics are not constant throughout spacetime - but nobody really wants this to be the case.

    1. Anonymous Coward
      Anonymous Coward

      Re: But what if?

      Its bad enough for atheists that there is so much fine tuning and the universe started from a causal agent outside of space time, never mind that we can't create a 'simple cell'.

      1. David Nash Silver badge

        Re: But what if?

        It's not fine tuning, as in "tuned by someone/something". It's just the anthropic principle.

    2. Yugguy

      Re: But what if?

      It was nothing of this earth, but a piece of the great outside; and as such dowered with outside properties and obedient to outside laws.

  14. Gordon Pryra

    Dark Matter? WTF?

    Next they will be saying that my ill humors are actually caused by little beasts that I can't see!

    Unless Dark Matter is just a modern term for God!

    In which case it makes perfect sense and I am willing to believe it!!

    @Destroy All Monsters - "where grants drives physics" made me spit my coffee onto the keyboard

    1. Charles 9 Silver badge

      Re: Dark Matter? WTF?

      "Unless Dark Matter is just a modern term for God!"

      Not so much as an acknowledgement that, "We're still rather in the dark about this." Calling it "dark" makes it more or less a placeholder, and I would think they would welcome plausible replacements for dark matter and dark energy. Just be sure to tick all the boxes in so doing.

      1. Richard 12 Silver badge

        Re: Dark Matter? WTF?

        For a while there were competing WIMPs and MACHOs. MACHOs have since lost, but WIMPs haven't been found or disproved.

        I live in hope for another "that's odd!?" Perhaps this observation will get us somewhere!

  15. Doctor Syntax Silver badge

    The problem I have with the dark matter theory is this. It's supposed to exert its effect on visible matter by gravity. In that case why is it lurking on the outer fringes of galaxies? Surely it ought to have clumped together with the regular matter.

    1. David Nash Silver badge

      It is with the regular matter, ie in the galaxies. Why would it not be in orbit, as much regular matter is?

  16. Graham Jordan

    No need for dark matter?

    I read this article last month; the science behind an EmDrive works for galaxies thus resulting in no need for Dark Matter.

    http://www.ibtimes.co.uk/emdrive-uk-scientist-claims-new-physics-explains-galaxy-rotation-theoretical-space-propulsion-1606367

    Maybe it's nothing, maybe it's everything. What's reassuring at least is the two sides are trying to prove themselves rather than use the standard God practice. "The lord works in mysterious ways. Now shut up and give me your money."

  17. Luiz Abdala

    Occam's Razor with fractally serrated edges..

    I like to think that the "simple" Equations we used to describe the Universe - like Newtonian Physics - appear correct until we find some extreme object that defies it, like something *really* massive, or *really* fast, or *really* small, or any attribute like it.

    Then we think they were wrong, but no, they just had several more terms that cancelled out in our scale of things...

    ... then we come up with Einstein's equations that have been working pretty good so far, with several terms that cancel each other when you deal with things in our scale but can't be neglected on a larger scale...

    ... but then you get some gaps in it for extreme objects... and you think them wrong (or you add constants to it, right? Are they constants in the end?)...

    ... and that some other equation will explain, that encompasses both Einstein's and Newton's, with several terms that cancel each other when dealing with smaller scale of things. Ad infinitum.

    In the end, all these theories were *almost* correct, but only for a small interval... just missing those pesky terms that can't be ignored when values are too extreme. Then we usually come up with some extreme theory that involves some form unobserved matter as the only explanation (this case), and try to come up with experiments that prove them.

    I call that form of understanding as Occam's Razor with Fractally Serrated Edges.

    As in, the simplest explanation is correct until you find a better one that explains all the previous ones in all the extreme cases.

    The Niels Bohr model of the atom worked up to a point, then it was totally replaced by something else that explained all the previous experiments... You couldn't say it was incorrect until Quantum Mechanics showed up and proved it wrong.

    1. LionelB

      Re: Occam's Razor with fractally serrated edges..

      The Niels Bohr model of the atom worked up to a point, then it was totally replaced by something else that explained all the previous experiments... You couldn't say it was incorrect until Quantum Mechanics showed up and proved it wrong.

      Pedantic correction: You couldn't say it was incorrect until experimental evidence showed up and proved it wrong; then quantum mechanics provided an explanation for that experimental evidence (although that may not have been the exact historical sequence of events).

      Apart from that, agreed: scientific theories are continually revised/refined/replaced to explain new "edge-case" evidence, frequently subsuming older theories in the process.

  18. Luiz Abdala

    Re: Occam's Razor with fractally serrated edges...

    Oh, yes, please, perfectly correct reasoning there.

    You come up with a new Theory, predict some experimental behaviour, and it happens as predicted, or a new Theory tries to explain the experimental data. Both work at once, sometimes.

    1. David Nash Silver badge

      Re: Occam's Razor with fractally serrated edges...

      Yes, and it is not helpful to use phrases such as "baffled boffins" (except for alliterative purposes).

      Talk of scientists being baffled and stumped only encourages those who don't understand the process. Too often scientists are accused of claiming to know everything, which makes such accusers pleased that they are "stumped" - nobody likes a know-it-all, after all. In reality science just describes what we see, and plausible theories to account for what we see. Bafflement occurs only if you take current accepted theory as cast-iron fact, which real scientists don't, despite what some science-illiterates and some sections of the press think.

      1. Uffish

        Re: baffled boffins not helpful

        This is The Register and you have just just made a "politically correct" statement. One pound into the swear box please!

  19. Anonymous Coward
    Anonymous Coward

    Ideas:

    It occurs to me and others that perhaps antimatter distributed anomalously with a -2.993% repulsion to matter would account for many of the observed effects attributed to dark matter including galactic rotation, expansion of the Universe and the apparent fractalization of recent galaxies.

    It also occurs to me that this could in light of the recent observations also explain the lack of "dark" matter in older galaxies due to the lack of a supermassive black hole which took time to grow to the size needed for pair production on a massive scale.

    In this case a combination of supermassive black holes, binary neutron stars and other phenomena could collectively be enough to generate antimatter on the scale needed due to an as-yet-undiscovered mechanism without significantly altering the Standard Model.

    The bonus feature here is that we have already explored much of the parameter space for antimatter,

    it obviously does not repel matter as much as some theories predicted and if it had more than about a 20% repulsion then this would have showed up in the 1920's.

    Intriguingly there are reports from the late 1990's which when viewed from this perspective eg proximity of positron emitting isotopes such as 23Mg, 18F and 40K could account for the observed effects of smoke rising over the apparatus and accelerometer readings which have never been explained to this day.

    Perhaps this is the missing piece of the puzzle and we can finally figure out where all the missing antimatter went. Hint: Its not missing at all!

    1. GrapeBunch Bronze badge

      Re: Ideas:

      I've long wanted antigravity entrained to antimatter. Never occurred to me that it doesn't have to be one-to-one with gravity. I wonder if the figure 0.02993 is the right side of an equation involving familiar constants, such as my first try e / (pi to the fourth) which google tells me is 0.02790583301. Not bad. Four pies because there's four dimensions and my tummy is empty. Science isn't done this way (at least not the 99.999% of Science that is work). Thank you all for indulging this fancy.

  20. Anonymous Coward
    Anonymous Coward

    RE. Re. Ideas

    Sometimes you have to just roll the dice.

    Perhaps one day it might take flight, its hard to know for sure. The next Einstein could be reading El Reg for all we know, and about to have his "Eureka!" moment.

  21. perrenod

    Something like this should be expected with Verlinde's emergent gravity. At high redshift and early times, the ordinary baryonic matter to dark energy ratio was much higher. In emergent gravity extra acceleration over and above the usual Newtonian dynamics explains flat MOND-like rotation curves and is due to,the interaction of ordinary matter and dark energy (a volume entropy contribution).

    No one including Verlinde has provided a dynamical cosmological model,that woukd allow this to be calculated, but the extra acceleration should be much less and thus rotation curves more like what is expected from baryons only, e.g. Newtonian dynamics.

    More observations needed to confirm, this is a small sample, and more development of the emergent gravity framework as well.

    1. Conundrum1885

      Re. entropic gravity

      A while ago I suggested that perhaps we should be looking not at any one hypothesis but the zones at which they interact?

      eg where entropic gravity and MiHsC/MOND are similar.

      LUX came up blank, ADMX was inconclusive.

      There are a lot of valid arguments for candidate particles, axions are speculative but marginally plausible however it might take decades to detect them.

      It later turned out that the diurnal radiation anomaly might have been specific to one type of tube and temperature was not compensated for adequately also atmospheric pressure might have been a factor due to interactions with the radiation.

      Ask Radu Motisan about this, he's got about 3 years or more of data and its still being analyzed now.

      The sensors are identical to mine however they are noticeably more sensitive to said effects if run above 400V so this is well worth investigating.

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