3 ms·

My point in, uh, scolding you for that take is that the circumstantial evidence is _massive_ for each of them, and I ... have a feeling... that you do not appre

by ajkjk 5y ago

My point in, uh, scolding you for that take is that the circumstantial evidence is _massive_ for each of them, and I ... have a feeling... that you do not appreciate that fact. (well! not for dark energy, but also nobody would disagree with you that dark energy isn't much of a theory. It's the other two that are well-founded in detailed experimental evidence). For my part I don't think the evidence for dark matter is any more 'circumstantial' than the evidence for massive neutrinos or the Higgs. Both are well indicated in extensive data .. by their byproducts and effects on other matter. But neither has been 'seen directly'; indeed it's not even clear what it would mean to see them directly, given that they apparently don't interact via the forces we can directly detect.

denton-scratch 5y ago
> feeling... that you do not appreciate that fact. Actually, I do; at least, I think that galaxies rotations are peculiar, but can be explained by the addition of unobserved matter. And I think inflation is a plausible candidate explation for the smoothness of the CMB. And I note the evidence that the universe's expansion appears to be accellerating, but I wonder is that is an observational error (rewally, I don't know - nobody I know is a physicist, or even interested in cosmology). So I'm an armchair cosmologist; same as I used to be an amateur astronomer. We serve a purpose: amateur astronomers are usually the first to spot new comets, because they have a wide perspective. I'd consume more material about cosmology, but it's generally either dumbed-down mass-media crap, or something about Lagrangians. I'm not a maths graduate, I did Philosophy. None of that invalidates my viewpoint.
- nwallin 5y ago
  > Actually, I do; at least, I think that galaxies rotations are peculiar, but can be explained by the addition of unobserved matter. That was the original hypothesis. It's literally the first thing the theorists came up with. There's an anomaly -- the simplest explanation is there's more ordinary matter there that we can't see. But why can't we see it? Well, we see stars because they emit light, we see gas clouds because the reflect light, so there's gotta be more matter there that doesn't give off light. What do we call it? Well, it's matter, and it's dark, so let's call it dark matter. Hypothesis 1.0, there's additional ordinary matter that is unobserved, was invalidated. It's one of the things that we know for certain is false. At this point, honestly, additional unobserved ordinary matter theory is about as credible as luminiferous aether theory for explaining the propagation of light. It's not a dumb idea -- "There's more stuff" is the simplest explanation, as is "Waves travel through a medium, so there must be a medium". But after more and more observations start piling up that are incompatible with the hypothesis, it's time to move on. Ordinary matter as an explanation for galactic rotation curves has been dead for about 40 years.
  - denton-scratch 5y ago
    > Ordinary matter as an explanation for galactic rotation curves has been dead for about 40 years. I wasn't aware of that; I didn't know that galactic rotation had been known to be peculiar for such a long time. I also wasn't aware that DM isn't just an example of "more stuff". I mean, I realise that DM can't be like other stuff; from what I've heard, it doesn't block light like other cosmic dust, and it doesn't seem to obey the same gravitational rules as other galactic stuff. I have no standing to tell experts they're wrong! But every lawyer knows that once the person you're talking to knows you're a lawyer, they'll start arguing with you about law. Lawyers often keep schtum about their trade, for that reason. So here I am, in a forum where there are people that know stuff, and I don't think it's wrong to ask questions.
- ajkjk 5y ago
  Yeah, that pretty much confirms what I was getting at: you believe you understand the theory-scape here, and you think that unobserved matter could be a valid explanation, because you know nothing about this why it in't. You're not wrong to doubt them for yourself, or to have fun thinking about it, or whatever, but casting it as some kind of ossified 'conventional thinking' that we should all be distrusting of isn't okay, and sounds a lot like other types of weird science distrust that happen a lot these days. Not entirely your fault, though; physics does a really bad job of, as, you say, educating people at a level more sophisticated than dumb-downed "because we said so" crap. But there know there are a lot of good youtubers and blogging filling in 'educated layperson' level of explanation.

by ajkjk 5y ago

denton-scratch 5y ago

> feeling... that you do not appreciate that fact. Actually, I do; at least, I think that galaxies rotations are peculiar, but can be explained by the addition of unobserved matter. And I think inflation is a plausible candidate explation for the smoothness of the CMB. And I note the evidence that the universe's expansion appears to be accellerating, but I wonder is that is an observational error (rewally, I don't know - nobody I know is a physicist, or even interested in cosmology). So I'm an armchair cosmologist; same as I used to be an amateur astronomer. We serve a purpose: amateur astronomers are usually the first to spot new comets, because they have a wide perspective. I'd consume more material about cosmology, but it's generally either dumbed-down mass-media crap, or something about Lagrangians. I'm not a maths graduate, I did Philosophy. None of that invalidates my viewpoint.

nwallin 5y ago
> Actually, I do; at least, I think that galaxies rotations are peculiar, but can be explained by the addition of unobserved matter. That was the original hypothesis. It's literally the first thing the theorists came up with. There's an anomaly -- the simplest explanation is there's more ordinary matter there that we can't see. But why can't we see it? Well, we see stars because they emit light, we see gas clouds because the reflect light, so there's gotta be more matter there that doesn't give off light. What do we call it? Well, it's matter, and it's dark, so let's call it dark matter. Hypothesis 1.0, there's additional ordinary matter that is unobserved, was invalidated. It's one of the things that we know for certain is false. At this point, honestly, additional unobserved ordinary matter theory is about as credible as luminiferous aether theory for explaining the propagation of light. It's not a dumb idea -- "There's more stuff" is the simplest explanation, as is "Waves travel through a medium, so there must be a medium". But after more and more observations start piling up that are incompatible with the hypothesis, it's time to move on. Ordinary matter as an explanation for galactic rotation curves has been dead for about 40 years.
- denton-scratch 5y ago
  > Ordinary matter as an explanation for galactic rotation curves has been dead for about 40 years. I wasn't aware of that; I didn't know that galactic rotation had been known to be peculiar for such a long time. I also wasn't aware that DM isn't just an example of "more stuff". I mean, I realise that DM can't be like other stuff; from what I've heard, it doesn't block light like other cosmic dust, and it doesn't seem to obey the same gravitational rules as other galactic stuff. I have no standing to tell experts they're wrong! But every lawyer knows that once the person you're talking to knows you're a lawyer, they'll start arguing with you about law. Lawyers often keep schtum about their trade, for that reason. So here I am, in a forum where there are people that know stuff, and I don't think it's wrong to ask questions.
ajkjk 5y ago
Yeah, that pretty much confirms what I was getting at: you believe you understand the theory-scape here, and you think that unobserved matter could be a valid explanation, because you know nothing about this why it in't. You're not wrong to doubt them for yourself, or to have fun thinking about it, or whatever, but casting it as some kind of ossified 'conventional thinking' that we should all be distrusting of isn't okay, and sounds a lot like other types of weird science distrust that happen a lot these days. Not entirely your fault, though; physics does a really bad job of, as, you say, educating people at a level more sophisticated than dumb-downed "because we said so" crap. But there know there are a lot of good youtubers and blogging filling in 'educated layperson' level of explanation.