4 ms·

The trouble is that MOND is just not worth your time. In fact, I would even object to calling it a 'theory' in the first place. MOND is just some wild idea, bu

The trouble is that MOND is just not worth your time. In fact, I would even object to calling it a 'theory' in the first place. MOND is just some wild idea, but a little thought should convince every physicist of its uselessness. It has major issues both in explaining experimental data and in its theoretical consistency. It justifiably receives next to no attention from the vast majority of (astro)physicists. In popular science the idea however does not seem to want to die, perhaps because it is so easily explained to a layperson. Of course this is a little frustrating for the community, but perhaps we should look at the upsides: more attention for science is probably a good thing, and explaining to people why MOND is so useless provides a good opportunity to discuss some proper physics.

deleted 2y ago
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ogogmad 2y ago
This is a weirdly arrogant comment given both TFA and the fact that professional physicists have worked on MOND and disagree with everything you've said. https://www.youtube.com/watch?v=n33aurhg788 https://www.youtube.com/watch?v=n33aurhg788 Is this typical behaviour for physicsts? Extremely strong opinions expressed in an abrasive way, out of proportion to the available evidence?
- prof-dr-ir 2y ago
  I just want to convey the following point: for the vast, vast majority of physicists the status of MOND is akin to what doctors think of the anti-vaccine theories. The evidence in the opposite direction is simply overwhelming. You refer to a non-scientific article and to a youtube video, but any vaccine sceptic can probably easily find exactly the same kind of material to support their view. That would almost certainly include a video by a "professional doctor". You might call me abrasive, but I am really just trying to be as clear as possible: this is the consensus in the field. And before you continue this discussion it might be worth pondering the following questions. How do you think doctors should convince vaccine skeptics that vaccines work? And how big a percentage of their weekend do you think they should spend engaging on the details with anti-vaxxers? (And, in this forum, how many downvotes from obvious non-experts should they be willing to accept?) In other words, what could I do to convince you in a reasonable amount of time?
  - haccount 2y ago
    [dead]
  - naasking 2y ago
    > The evidence in the opposite direction is simply overwhelming. No, many of LCDM's successes were not predictions but post-hoc adjustments, where MOND had many successful predictions, even though we had no expectation for it to work: From galactic bars to the Hubble tension: weighing up the astrophysical evidence for Milgromian gravity, https://arxiv.org/abs/2110.06936 https://arxiv.org/abs/2110.06936 Yours is an opinion shared by particle physicists because they focus on particles, but astronomers are more neutral on MOND. It almost always just works (it's an "effective theory"), even though we don't know why.
  - anon291 2y ago
    > . How do you think doctors should convince vaccine skeptics that vaccines work I think this is the root of the problem, because most 'vaccine skeptics' don't actually claim that vaccines don't work. I say this as someone who is not skeptical of vaccines at all. But when I read doctors defending vaccines it comes across as so out of touch with what the 'skeptics' are concerned about. > In other words, what could I do to convince you in a reasonable amount of time? For me at least, you don't need to convince me. It's clear that there are a lot of issues with all current formulations of gravitation. It's a pick your poison deal. You say MOND is wrong due to overwhelming evidence. I say the dark matter theories are wrong due to overwhelming lack of evidence that the stuff that is purported to exist even exists. Both wrong... It's hardly a bad thing to be labeled wrong when no one is right. In general, if you're not right, then I don't see the point in dissing on those you consider wrong
- anon291 2y ago
  In general, scientists (and academics more generally) suffer from some of the most dogmatic thinking on the planet. It's no surprise that many of them find themselves in institutions that were once known for their theology departments.
lloeki 2y ago
> The trouble is that MOND is just not worth your time. [...] MOND is just some wild idea Sometimes you gotta be wrong before you get it right. I mean, Newtonian mechanics are "wrong" but served us well at some scales for a while, and that it observationally failed in others led us to relativity. Even "relativity" took iterative steps, from Poincaré's Lorentz invariant theory (or even earlier with Galilean relativity) all the way to GR via special/restricted relativity, the latter name having been retconned because it's only valid in restricted special cases and fails to unify generally. And we know GR fails to unify with quantum mechanics, so one of them (or both) gotta give. So even if something as MOND were "wrong" and known to be wrong (definitely so), there's still value in experimenting with it to get a better understanding of things. That's just how things work.
- prof-dr-ir 2y ago
  > there's still value in experimenting with it I disagree: some experiments are just not worth our time. I wrote about such a situation three years ago: https://news.ycombinator.com/item?id=26656206 https://news.ycombinator.com/item?id=26656206 My view is that it applies here as well.
naasking 2y ago
> I would even object to calling it a 'theory' in the first place. That's why we have the term "effective theory".

deleted 2y ago

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ogogmad 2y ago

This is a weirdly arrogant comment given both TFA and the fact that professional physicists have worked on MOND and disagree with everything you've said. https://www.youtube.com/watch?v=n33aurhg788 https://www.youtube.com/watch?v=n33aurhg788 Is this typical behaviour for physicsts? Extremely strong opinions expressed in an abrasive way, out of proportion to the available evidence?

prof-dr-ir 2y ago
I just want to convey the following point: for the vast, vast majority of physicists the status of MOND is akin to what doctors think of the anti-vaccine theories. The evidence in the opposite direction is simply overwhelming. You refer to a non-scientific article and to a youtube video, but any vaccine sceptic can probably easily find exactly the same kind of material to support their view. That would almost certainly include a video by a "professional doctor". You might call me abrasive, but I am really just trying to be as clear as possible: this is the consensus in the field. And before you continue this discussion it might be worth pondering the following questions. How do you think doctors should convince vaccine skeptics that vaccines work? And how big a percentage of their weekend do you think they should spend engaging on the details with anti-vaxxers? (And, in this forum, how many downvotes from obvious non-experts should they be willing to accept?) In other words, what could I do to convince you in a reasonable amount of time?
- haccount 2y ago
  [dead]
- naasking 2y ago
  > The evidence in the opposite direction is simply overwhelming. No, many of LCDM's successes were not predictions but post-hoc adjustments, where MOND had many successful predictions, even though we had no expectation for it to work: From galactic bars to the Hubble tension: weighing up the astrophysical evidence for Milgromian gravity, https://arxiv.org/abs/2110.06936 https://arxiv.org/abs/2110.06936 Yours is an opinion shared by particle physicists because they focus on particles, but astronomers are more neutral on MOND. It almost always just works (it's an "effective theory"), even though we don't know why.
- anon291 2y ago
  > . How do you think doctors should convince vaccine skeptics that vaccines work I think this is the root of the problem, because most 'vaccine skeptics' don't actually claim that vaccines don't work. I say this as someone who is not skeptical of vaccines at all. But when I read doctors defending vaccines it comes across as so out of touch with what the 'skeptics' are concerned about. > In other words, what could I do to convince you in a reasonable amount of time? For me at least, you don't need to convince me. It's clear that there are a lot of issues with all current formulations of gravitation. It's a pick your poison deal. You say MOND is wrong due to overwhelming evidence. I say the dark matter theories are wrong due to overwhelming lack of evidence that the stuff that is purported to exist even exists. Both wrong... It's hardly a bad thing to be labeled wrong when no one is right. In general, if you're not right, then I don't see the point in dissing on those you consider wrong
anon291 2y ago
In general, scientists (and academics more generally) suffer from some of the most dogmatic thinking on the planet. It's no surprise that many of them find themselves in institutions that were once known for their theology departments.

lloeki 2y ago

> The trouble is that MOND is just not worth your time. [...] MOND is just some wild idea Sometimes you gotta be wrong before you get it right. I mean, Newtonian mechanics are "wrong" but served us well at some scales for a while, and that it observationally failed in others led us to relativity. Even "relativity" took iterative steps, from Poincaré's Lorentz invariant theory (or even earlier with Galilean relativity) all the way to GR via special/restricted relativity, the latter name having been retconned because it's only valid in restricted special cases and fails to unify generally. And we know GR fails to unify with quantum mechanics, so one of them (or both) gotta give. So even if something as MOND were "wrong" and known to be wrong (definitely so), there's still value in experimenting with it to get a better understanding of things. That's just how things work.

prof-dr-ir 2y ago
> there's still value in experimenting with it I disagree: some experiments are just not worth our time. I wrote about such a situation three years ago: https://news.ycombinator.com/item?id=26656206 https://news.ycombinator.com/item?id=26656206 My view is that it applies here as well.

naasking 2y ago

> I would even object to calling it a 'theory' in the first place. That's why we have the term "effective theory".