The current theoretical model for the composition of the universe is that it's made of normal matter, dark energy and dark matter. A new University of Ottawa study challenges this.
  • henfredemars@infosec.pubEnglish
    80·
    3 months ago

    This model combines two ideas—about how the forces of nature decrease over cosmic time and about light losing energy when it travels a long distance. It’s been tested and has been shown to match up with several observations, such as about how galaxies are spread out and how light from the early universe has evolved.

    These hypotheses never seem to stand up to rigorous analysis. Still, always welcome the discussion.

    • addie@feddit.uk
      25·
      3 months ago

      Absolutely. On the one hand, having ~26% of the known universe consisting of a substance that we cannot detect directly leaves a lot of questions open. On the other hand; dark matter is postulated because otherwise things like galaxy rotation curves don’t match what we believe they should be from general relativity, and this theory doesn’t seem to address that.

      https://en.wikipedia.org/wiki/Bullet_Cluster#Significance_to_dark_matter

      Also, light ‘losing energy’ would be a violation of the first law of thermodynamics, unless it loses it ‘to’ somewhere.

          • xionzui@sh.itjust.works
            2·
            3 months ago

            I’m no expert, and I don’t think we know for sure, but it sounds like it might be related to the increase in vacuum energy from the added space. It’s also possible the total amount of net energy in the universe is 0 and conserved

      • bouh@lemmy.world
        3·
        3 months ago

        At some point we may have to review some theories though. The idea that light would lose energy over extra long distances at least makes sense unlike some kind of latter that we can’t detect and we can’t figure out why it would either still be there but not more than it is.

        This is kind of how time was supposed to be absolute. Einstein never received a Nobel for the theory of relativity because of how suspicious it seemed at the time.

        • SpacetimeMachine@lemmy.world
          5·
          3 months ago

          There being a substance that does not interact with light at all doesn’t seem that far fetched to me. There is nothing in the laws of the universe that says “Humans must be able to detect everything that exists because otherwise it wouldn’t make sense.”

          It feels entirely possible that we won’t be able to detect dark matter through any conventional means that we currently have.

          • bouh@lemmy.world
            1·
            3 months ago

            It’s not about humans. It’s about science. “there is dark matter that doesn’t interact with matter” can as well be “there is magic, and I cannot be proven wrong”.

            • bitcrafter@programming.dev
              3·
              3 months ago

              Dark matter does interact with matter, though: it interacts gravitationally. It just does not interact in other ways (that we know of yet). All you would have to do to disprove the existence of dark matter is to show that some things interact with it gravitationally but others don’t. However, this is not what we see; what we actually see is a whole bunch of separate things that all experience the effect of the existence of dark matter in the same way. It’s effectiveness as an explanation in this regard is exactly what makes it so difficult to dethrone.

    • bitwaba@lemmy.world
      22·
      3 months ago

      This is the same researcher that said the universe is 26.7 billion years old based on the JWST data instead of 13.8.

      Happy to see ideas thrown out there to help us understand what dark matter is, but I’m really looking forward to all the random videos that eventually come out explaining why it holds up against a whole bunch of observational evidence while it ignores all the other observational evidence it doesn’t hold up against.

  • catloaf@lemm.eeEnglish
    50·
    3 months ago

    “In standard cosmology, the accelerated expansion of the universe is said to be caused by dark energy but is in fact due to the weakening forces of nature as it expands, not due to dark energy.”

    Fascinating! I’m looking forward to seeing where this goes. The “tired light” theory they mention doesn’t seem to have held up to scrutiny, but maybe there’s something else about weakening over time or distance that we haven’t observed yet.

    • MaliciousKebab@sh.itjust.worksEnglish
      3·
      3 months ago

      How would the gravitational forces weakening accelerate the expansion speed? It would at best “not slow it down”, you can’t explain the speed increase with this logic. That just sounds wrong. Am I missing something?

      • nilloc@discuss.tchncs.deEnglish
        1·
        3 months ago

        Would it be that as gravity weakens, the inertial forces of a spinning galaxy allow it to spread without the gravitational drag that would otherwise slow it down as it expanded?

        This is purely my filthy casual’s intuitive take. I’m happy to hear what’s off about it.

        • MaliciousKebab@sh.itjust.worksEnglish
          1·
          3 months ago

          I think you mixed up galaxies moving away from each other, and a galaxy’s stars etc. moving in space.

          As per Einstein’s relativity theory, gravitational force has infinite range. So there will always be some pulling force between galaxies, which means they would eventually slow down and and eventually start moving towards each other. But our observations suggest that they are moving even faster day by day. So there must be some force that is stronger than gravity and it must be somehow pushing objects.

          So gravity by itself doesn’t explain the speed increase of universe’s expantion.

  • antihumanitarian@lemmy.worldEnglish
    25·
    3 months ago

    Don’t get too excited, this is a pretty fringe theory that doesn’t really have experimental evidence. They were able to make some observations fit with their theory without dark matter yes, but not all of them. The tired light part in particular has a lot of contradictions with observation that they don’t explain.

    So interesting, but far from definitive.

    • yesoutwater@lemm.ee
      9·
      3 months ago

      Couldn’t the same be said for the proof of dark matter?

      They were able to make some observations fit with their theory with dark matter yes, but not all of them

    • Captain Aggravated@sh.itjust.worksEnglish
      4·
      3 months ago

      I’m a workshop kind of guy that enjoys space documentaries. For my part, I see “dark matter” as a known hole in our current understanding of cosmology, and I bet when we figure out how it does actually work it’ll lead to some really cool TV shows.

    • Daft_ish@lemmy.world
      3·
      3 months ago

      These type of comments always throw me through a loop.

      Scientist:

      Makes hypothesis, does analysis, writes paper, and presents work for other academics to review.

      Lemmy poster:

      Logs into lemmy. Posts “i think not mr scientist”. Recieves upvotes.

      While I would certainly like to say I understood any of this. This post has not met any rigorous standard of debunking the researchers findings.

      It’s fine if you have knowledge on this particular subject but it kinda seems like you’re just throwing shade.

      • Endward23@futurology.todayEnglish
        1·
        2 months ago

        While I would certainly like to say I understood any of this. This post has not met any rigorous standard of debunking the researchers findings.

        Thats not what the posting claimed to be. You missunderstand. Either intentionally or just as a fact.

  • TimewornTraveler@lemm.ee
    21·
    3 months ago

    This stuff is way, way over my head. And probably most of humanity right now. In this moment I can feel some envy and admiration towards whoever is around to understand the great breakthroughs we may one day have on this matter.

    • MisterD@lemmy.ca
      22·
      3 months ago

      Coles notes: scientists made calculations on the universe and it didn’t make sense because the math says there should be more mass and energy than what they know exists. So they called the missing mass dark matter and the missing energy, dark energy.

      Now some guy in Ottawa figured out better math that doesn’t need the “dark” stuff to make the math make sense.

      • ApatheticCactus@lemmy.worldEnglish
        9·
        3 months ago

        My understanding of dark energy is a little different. As I understand it, we figured gravity pulls things together, right? So everything should be kinda slowly falling back together from the big bang. It was theorized to end in a ‘big crunch’ where the universe collapses back and then explodes again in a cycle.

        Only when they tried to measure how fast distant objects were moving relative to us, they found that things were still moving away from each other. More than that, the farther away things were, the faster they were moving. Meaning distant objects were accelerating.

        Acceleration requires energy, but we don’t know the mechanism behind this, or where the energy comes from. Hence, dark energy.

          • Ddub@lemmy.ca
            5·
            3 months ago

            kinda, dark energy is the unknown explanation for the expansion of the universe. Once we understand it enough to know what it is responsible for it’ll no longer be dark.

            • Harbinger01173430@lemmy.world
              1·
              3 months ago

              You humans and your primitive knowledge. The rest of the universe knows that this dark energy you haven’t found out yet is called Mana and allows miracles to be made. /S

  • Krudler@lemmy.worldEnglish
    12·
    3 months ago

    I went and read the research.

    I’m not an expert and as such can’t really analyze it fully. But what I took away is that it aimed to test a part of new theory by with a very narrow measurement, using early-universe density oscillations. They left dark matter out of the equation with the new model, and it was a smashing success if you’re willing to overlook that it requires the universe to be a completely different age than it is… In short, this is shenanigans.

    edit: I’m fine being wrong if I am, I’d love to know more from informed readers. That’s just what I took away https://iopscience.iop.org/article/10.3847/1538-4357/ad1bc6#apjad1bc6s3

    edit2: It also presumes the “tired light theory” is true. Tired light is the flat earth of astrophysics/cosmology. Yeah, there are contrarian knuckleheads in every discipline.

    • Endward23@futurology.todayEnglish
      1·
      2 months ago

      Tired light is the flat earth of astrophysics/cosmology.

      Does it really say it? Can you please quote the piece?

  • Queen HawlSera@lemm.eeEnglish
    2·
    3 months ago

    It’s almost like we shouldn’t have been all in on the thing that literally has less evidence behind it than fucking psychic powers.

    • zaphod@feddit.de
      3·
      3 months ago

      It’s not that dark matter was the only theory, there are also different theories based on modified newtonian dynamics (MOND), these aren’t any better than dark matter though, maybe even worse theories.

    • Gabu@lemmy.world
      2·
      3 months ago

      They say, while being fully behind a hypothesis with no supporting evidence and while not understanding the research.