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Space Science

Scientists Hope Euclid Telescope Will Reveal Mysteries of Dark Matter (theguardian.com) 44

In just a few weeks, a remarkable European probe will be blasted into space in a bid to explore the dark side of the cosmos. From a report:ÂThe $1bn Euclid mission will investigate the universe's two most baffling components: dark energy and dark matter. The former is the name given to a mysterious force that was shown -- in 1998 -- to be accelerating the expansion of the universe, while the latter is a form of matter thought to pervade the cosmos, provide the universe with 80% of its mass, and act as a cosmic glue that holds galaxies together. Both dark energy and dark matter are invisible and astronomers have only been able to infer their existence by measuring their influence on the behaviour of stars and galaxies.

"We cannot say we understand the universe if the nature of these dark components remains a mystery," said astrophysicist Prof Andy Taylor of Edinburgh University. "That is why Euclid is so important." Taylor added that UK scientists had played a key role in designing and building the probe. For example, one of its two main instruments, the craft's Vis imager, was mostly built in the UK. "We thought what would be the biggest, most fundamentally important project we could do?" Taylor said. "The answer was Euclid, which has now been designed, built and is ready for launch." Euclid was intended to be launched last year on a Russian Soyuz rocket. However, after the invasion of Ukraine, the European Space Agency ended its cooperation with the Russian space agency, Roscosmos, and instead signed a deal to use a Falcon 9 rocket from Elon Musk's SpaceX company.

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Scientists Hope Euclid Telescope Will Reveal Mysteries of Dark Matter

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  • Good (Score:4, Insightful)

    by Cpt_Kirks ( 37296 ) on Monday June 19, 2023 @03:23PM (#63616240)

    I'll be interested to see the results.

    Bet they won't point to either "dark matter" or "dark energy".

    There is something fundamentally wrong with both concepts.

    I don't think either are needed. Just better math and theories.

     

    • Re: (Score:2, Interesting)

      by Black Parrot ( 19622 )

      And I think they're both real.

      Although, AIUI, when it comes to dark energy we need an explanation for why the universe is expanding as *slowly* as it does, since the known vacuum energy suggests that it should be expanding 30 or 60 OOM faster.

    • by taustin ( 171655 )

      Dark energy has been proven [home.cern] by people who know a lot more about it than you (or me).

      Do you believe the earth is flat, too? Did Elvis tell you that the last time he visited?

    • Re:Good (Score:5, Insightful)

      by HiThere ( 15173 ) <charleshixsn.earthlink@net> on Monday June 19, 2023 @04:33PM (#63616442)

      Both "dark matter" and "dark energy" exist. The question is "What are they?". Your mistake is to think of them as something more than a placeholder name that references certain measurements that are anomalies. When there are a good theories for them, they'll be given a different name.

      • Right. When they discovered that there were hepatitis cases that were not Hepatitis A or Hepatitis B they did not call it Hepatitis C, they called it "Non A, Non B". Later they identified C, D, and E - it was not one disease.

    • Maybe, but its getting difficult to fit any other theory to all of the observed data. Also cosmological inflation in the early universe looks a lot like dark energy, but at vastly higher energy density. Also not proven, but provides a good explanation.

      More observations are needed - and this project will provided some of those.
  • Uh oh... (Score:3, Funny)

    by sconeu ( 64226 ) on Monday June 19, 2023 @03:33PM (#63616276) Homepage Journal

    What if dark matter is non-Euclidean?

  • by ffkom ( 3519199 ) on Monday June 19, 2023 @03:33PM (#63616278)
    An interesting presentation providing some evidence how the dark matter concept is incompatible with observations made on "wide binary star systems": https://www.dropbox.com/s/2r3x... [dropbox.com]
    • by ffkom ( 3519199 )
      ... argh, should have written "Recent evidence against "MOND" as an alternative concept to "dark matter".
      • by ffkom ( 3519199 ) on Monday June 19, 2023 @03:41PM (#63616294)
        The opposite statement (one that matches the subject of this posting) was actually made in another recently published study: https://arxiv.org/pdf/2305.046... [arxiv.org]
        • I would be delighted if Euclid ends up disproving the concept of "dark matter." It has always seemed to me like a way of saying, "The universe doesn't behave the way we expect based on what we know of physics, so we'll invent a kind of matter that is completely invisible, to make the numbers work out." The only evidence for "dark matter" is that the math doesn't work out. In accounting, when the math doesn't work out, we're pretty sure somebody did the math wrong.

          Maybe dark matter is real, I don't know, but

          • I would be delighted if Euclid ends up disproving the concept of "dark matter." It has always seemed to me like a way of saying, "The universe doesn't behave the way we expect based on what we know of physics, so we'll invent a kind of matter that is completely invisible, to make the numbers work out." The only evidence for "dark matter" is that the math doesn't work out. In accounting, when the math doesn't work out, we're pretty sure somebody did the math wrong.

            This is a bad analogy. It is not that we did the math wrong, you are proposing that the solution to our accounting problem is to invent a new kind of math. If your numbers don't add up in accounting you may be detecting a real theft (people dumping extra money in the vault is a lot rarer).

            • Re: (Score:2, Insightful)

              by Tony Isaac ( 1301187 )

              If your numbers don't add up in accounting you may be detecting a real theft

              That's pretty much the point.

              In the real world, if the numbers don't add up, it is a strong indicator that something fishy is going on. In Astronomy, we invent "dark matter." Perhaps the answer is simpler than dark matter: perhaps there is something wrong with the underlying theory. Some of the related hypotheses are pretty "out there"...inflation, and an enormous explosion of nothingness, to name a couple.

              • by Jimekai ( 938123 )
                I like explosions of nothingness, like when I realized that Pi was a spiral. So here goes nothing. The ratio 22/7 equates to Pi at nearly 3 decimal places, and 355/113 goes to 6 places. In other words there is always a rounding error at whatever number of decimal places of Pi are selected. Within that error there is a notch in any sphere that could allow the entry and oscillation of, lets for arguments sake call it a positron, when the rounding gap is fixed at the Planck length. Mashing up quantum theory I
          • by Roger W Moore ( 538166 ) on Monday June 19, 2023 @07:35PM (#63616788) Journal

            It has always seemed to me like a way of saying, "The universe doesn't behave the way we expect based on what we know of physics, so we'll invent a kind of matter that is completely invisible, to make the numbers work out."

            It's more like saying that the universe seems to behave as if there is more mass out there than just baryons and since this is a consistent observation across multiple different experiments that have looked at both the universe today and the universe 300k years after the Big Bang and all of them, each using very different maths, give the same consistent result there is every reason to believe that it is correct.

            In accounting, if the maths does not add up and you get in different teams of accountants and they all use different accounting techniques but all get to the same conclusion that the maths does not add up in the same way then at some point you presumably realise that there is something real in the underlying financial data that all the teams are analysing because it would be overwhelmingly unlikely that everyone would make different mistakes that somehow all gave the same wrong answer.

            Physics is at that point now. Whatever "Dark Matter" turns out to be it is definitely something real that we have not accounted for whether that be a new type of invisible matter, modified laws of Newtonian dynamics (MOND) or something else that nobody has thought of we are clearly missing something real. Physicists may disagree on how to explain the many independently collected data but absolutely none of us doubt that there is something real that needs explaining.

            • If the math so neatly worked out, as you say, then your conclusion would also be correct. But as we are able to observe more precisely the beginnings of the universe, the more surprises we find. https://www.npr.org/2023/02/22... [npr.org]

              It's far too early in our understanding of the universe, to make such confident conclusions.

              • Yes, but it is not just the cosmic microwave background radiation that shows Dark Matter, the rotation curves of galaxies in the present-day universe show excess matter with a spherical distribution. Then there is the fact that nobody understood why there are so many spiral galaxies since these are unstable...unless you add Dark Matter. Lastly, there is the bullet cluster that shows two colliding galaxies where the main mass of the two clusters measured by gravitational lensing is not in the same place as t
                • As is often said around here, correlation is not causation. You can have a million coinciding facts that all agree with (are correlated to) an underlying hypothesis that is flawed. The count of correlations is irrelevant. The same cause could be the reason for all the other correlations, but it could at the same time be true that we've still misinterpreted the root cause. A single observation that disagrees with the previous interpretation, can be enough to overturn the entire mountain of what we thought we

                  • As is often said around here, correlation is not causation.

                    That works fine when you have two observations A and B and try to conclude that A causes B or vice versa. However, here we have A, B, C, D and more and you are wrong when you say that the count of correlations is irrelevant. When you only have two observables there is a high probability of random correlation. However, when you have many uncorrelated (based on current understanding) observables that all appear to be different in a correlated manner the random chance of all of them being correlated accidenta

                    • you are wrong when you say that the count of correlations is irrelevant

                      I'll cite an example that is very relevant here. Here on earth, we have billions of observations that support the hypothesis that any object that has mass, can be observed. Many of these observations are unrelated to each other. We have literally never observed an exception to this rule. Could the hypothesis be wrong, that mass can take a form that is not observable? Perhaps, but we've never proved such a thing. Such a finding would by countered by those billions of observations, but would then be shown to

        • by ceoyoyo ( 59147 )

          Yes. It seems to depend on which systems you look at whether MOND fits or not.

      • It has been a while since I did the survey, but the the last few times I did a search on ArXiv, "MOND" was picking up several paper titles per week. That's not a "suppression" of the subject - it's disinterest by most researchers. They don't think it's a useful idea. Though if the few people still working with it do come up with something significant, it will get into the literature pretty rapidly.

        I may not be a professional astronomer, but if I'm doing occasional searches for "MOND" papers, I bet that a l

  • WHAT DOES EUCLID DO?
    • Yeah I know, you have to read the actual article to find out what it does. But who looks there???

      TLDR...Euclid is built to study gravitational lensing. It "has the same resolving power as Hubble" but covers 1/3 of the night sky. With a field of view that large, astronomers are hoping to find patterns they couldn't easily find with a more traditional telescope.

  • It's interesting how they they intend to find that which cannot be described yet: they're looking for small distortions in the view, the tiny ripples caused by gravitational lensing. Kinda cute.

  • by Gravis Zero ( 934156 ) on Monday June 19, 2023 @05:35PM (#63616576)

    Scientists Very Excited To Be Disappointed In the Near Future

    I'm all for it. I hope it works out as well as they expect.

    • Scientists Very Excited To Be Disappointed In the Near Future

      I'm all for it. I hope it works out as well as they expect.

      Even if they don't find the evidence they want, the lack of evidence itself will be evidence of something else.

      Both positive and negative results still drive knowledge forward.

      • Both positive and negative results still drive knowledge forward.

        You're absolutely correct. However, in the worst case scenario, the machine fails and doesn't return usable data.

        • That's possible with any machine. If remote machines, JWST could have been destroyed during launch or could have stuck unable to open up it's umbrella, and so not giving any useful info that it was designed for (am sure they would have received info on what screwed up so that they know what not to do in the future).

          Or something down to earth, LHC could have failed, in which case we could either decide to spend more resources to fix it, or leave it at it's "broken" state. It would probably have provided some

  • How many years are we going to spend money on this broken theory. Dark X and string theory produce the biggest boondoggles.

The truth of a proposition has nothing to do with its credibility. And vice versa.

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