“I soon became convinced… that all the theorizing would be empty brain exercise and therefore a waste of time unless one first ascertained what the population of the universe really consists of.” –Fritz Zwicky

When we look out at the galaxies in the Universe, watching how they rotate, we find that the starlight we see is woefully insufficient to explain why the galaxies move as they do. In fact, even if we add in the gas, dust, and all the known matter, it doesn’t add up.

Image credit: Stefania.deluca of Wikimedia Commons.

Image credit: Stefania.deluca of Wikimedia Commons.

Normally, we talk about dark matter as the only viable solution, but it turns out that MOND, or MOdified Newtonian Dynamics, is actually superior at explaining galactic rotation to dark matter. Could it be the solution to the “missing mass” (or “missing light”) problem?

Your browser does not support the video tag. Image credit: Stacy McGaugh, via https://www.astro.umd.edu/~ssm/mond/fit_compare.html.

Your browser does not support the video tag.
Image credit: Stacy McGaugh, via https://www.astro.umd.edu/~ssm/mond/fit_compare.html.

Find out on this week’s Ask Ethan!

Comments

  1. #1 Denier
    United States
    June 26, 2015

    I’m really starting to sour on the idea of Dark Matter. First, it does NOT correctly model galactic spin. Second, the bodies in our solar system have been tracked with an incredible amount of precision and although DM is supposed to make up 80% of all gravitationally active stuff, they can find absolutely no trajectories of anything that would indicate any sort of DM influence.

    MOND is a dog with a different set of fleas. I don’t think it is the correct answer either.

    My current favorite DM alternative is Antimatter Antigravity. The great thing about this theory is that it also accounts for Dark Energy, AND the theory is completely testable! They are currently conducting tests at CERN to determine if anti-hydrogen falls up or down. The preliminary results do NOT support Antimatter Antigravity,…..but….. the error bars on the results are plus or minus 100%. It was reported on everywhere that anti-hydrogen has been proven to fall down, but if you actually read the paper instead of the stories in the press the results are not conclusive. They’re still testing to see if anti-hydrogen falls up or down.

    If anti-hydrogen can be shown to fall up instead of down, the whole theory of Dark Matter will be relegated almost immediately to the list of wrong ideas that achieved consensus.

  2. #2 Wow
    June 26, 2015

    “I’m really starting to sour on the idea of Dark Matter”

    Dark matter just phoned me. It doesn’t give a shit.

  3. #3 Wow
    June 26, 2015

    Oh, by the way, do some back of the envelope figuring of the dark matter density in our solar system and how it would affect a body’s trajectory within it before you make assinine claims like

    “they can find absolutely no trajectories of anything that would indicate any sort of DM influence.”

    Ancient greeks could find absolutely no mass loss that would indicate any sort of “mass energy conversion”.

  4. #4 See Noevo
    June 26, 2015

    “Could dark matter not exist?”

    I find it remarkable that such a question is being asked.
    We’ve been told by scientists for at least several decades that Dark Matter not only exists, but is over 5 times more prevalent than regular matter.

    And what about the even more expansive Dark Energy (supposedly 68% of the universe)?
    Might both DE and DM be dispatched to the dustbin of bogus science history?

  5. #5 Wow
    June 26, 2015

    Yes. Because you’re really butthurt when people ask “Could god not exist?”.

    Did you ever think of looking at the answer?

    To either of them? I guess you couldn’t see them, hmm?

  6. #6 Omega Centauri
    June 26, 2015

    Ethan. We now have claims for hundreds of “dark galaxies” in the Virgo cluster. These are described as roughly the spatial extent of the Milky Way, but with a thousand times fewer stars. The claim that they are 99% dark matter is also made. Supposedly the cluster is dense enough that the gas/dust might have been stripped off, but the DM remains, so that the ration of dark matter to baryonic matter is much higher than for “normal” galaxies. If we can observe galaxies with different DM/BM ratios, I think this would be very tough to explain with something like MOND.

  7. #7 Michael Kelsey
    SLAC National Accelerator Laboratory
    June 26, 2015

    @See Noknowledge #4: You write, “I find it remarkable that such a question is being asked.” Did you bother to read the article? Hell, did you even bother to pull you head out of your fat, lazy arse long enough to even read the TITLE of the article? Do you have enough command of the English language to know what a phrase like “Ask Ethan” means?

    Given your interminable penchant to ask questions, even when you have no interest in the answer, why do you find it “remarkable” that other people might ask questions? Perhaps it was remarkable to see someone else ask an intelligent question, based on wishing to learn more about some subject about which they’ve only heard a little. It’s a pity you’re so incapable of doing the same.

  8. #8 See Noevo
    June 26, 2015

    To Michael Kelsey #7:

    I think that, at a minimum, the scientists should at least have the humility to change the name of Dark Matter to something else, like Dark Thing. The reason being, “Matter” is considered to be made of particles, but no one knows what Dark Matter is made of.

    “The scariest possibility may be that dark matter is made of something impossible to find —some particle that interacts with regular matter only via gravity and no other force. In such a case researchers would have no HOPE of catching it in a detector.”

    That’s just one of three times the word “hope” is used in this remarkable article.
    http://www.nature.com/news/dark-matter-search-considers-exotic-possibilities-1.14459

    Reminds me of “hopeful monsters” in evo fiction.

  9. #9 Brian
    June 27, 2015

    Ethan, please finally ban “Wow”. He trolls these comments trying to start arguments nonstop. Besides being an obviously miserable virgin, he ruins the comments.

  10. #10 Wow
    June 27, 2015

    “If we can observe galaxies with different DM/BM ratios, I think this would be very tough to explain with something like MOND.”

    True.

    Though MOND could certainly explain SOME of the discrepancy.

    Since we know that at least SOME matter-like stuff is there, yet we don’t know that MOND *has* to be there too, lets check out the matter stuff and deduct the effects of that first. Anything left could be errors in DM theories, MOND or some other phenomena, but in any case we’ll have some idea of what the magnitude of the remaining issue is.

  11. #11 Wow
    June 28, 2015

    “The reason being, “Matter” is considered to be made of particles”

    And what ARE particles, HMM?

    And why isn’t dark matter made of it?

  12. #12 Wow
    June 28, 2015

    Ben, please STFU.

    Where are you while riomar or seenowt are shitting over the blog, hmm?

    Oh, that’s right, they’re religious, therefore their ignorance must be allowed, right? Or maybe you even agree with them.

  13. #13 Wow
    June 28, 2015

    (that should have been Brian, by the way)

    “Besides being an obviously miserable virgin”

    ????

    You wouldn’t be trolling and looking for an argument, would you, brian?

    Maybe you’re just trying to pretend you’re nice by, um, proclaiming someone is a virgin when you have no way to say so and proscribing miserableness as a required part of being virgin, or indication of virginity.

    Maybe you were miserable as a child until daddy took that virginity away from you and you were suddenly happy.

    Or maybe making claims with no evidence or reason to make them is indication of ill will.

    You decide.

    But don’t pick one for yourself and another for me. Be consistent.

  14. #14 AC
    June 29, 2015

    At some point Ethan will have to make the decision to ban him or not, at least if he intends on growing his site and getting readers more involved.

    He can’t possibly hope to get readers involved when you have someone like Wow spewing condescension and hate every other comment. You almost feel for the guy though, he must live a miserable life and takes it out on people through anonymous blog comments. Truly a man of courage and honor.

  15. #15 Wow
    June 29, 2015

    And yet another tone troll.

    Tiresome.

  16. #16 Wow
    June 29, 2015

    Oh, by the way, AC, go read riomar9.

    Then come back here and give us your wisdom…

  17. #17 Brian
    yeah
    July 1, 2015

    Thanks, Wow, for proving my point. You posted 5 angry comments in response to my ONE comment, which simply pointed out that you’re argumentative. You’re an angry troll. Grow up.

  18. #18 Wow
    July 2, 2015

    You didn’t have one, Brian.

    I think you and AC should be banned: you don’t do anything other than post about how others should be banned. No positive contribution, just spite.

    i take it you concur that the evidence of post history determines this to be necessary, right?

  19. #19 Stephen
    April 8, 2016

    Did anyone explain how the observed expansion of the universe could not be caused by gravity produced by super massive objects beyond our perception, that are larger than our perceived universe?

    These would be fractal analogs of protons and neutrons drawing all matter from the space between, affecting the acceleration.

    This would put the structures at each extent of our universe just beyond our perception.

    Seems if a mass and acceleration can be determined, for the universe, the attracting mass should be estimable.

  20. #20 Stephen
    April 8, 2016

    Really

New comments have been temporarily disabled. Please check back soon.