5 ms·

One of the best pithy comments on general relativity and dark matter was made by someone on HN about a week ago. I think it summarizes the situation quite well.

One of the best pithy comments on general relativity and dark matter was made by someone on HN about a week ago. I think it summarizes the situation quite well. But, inexplicably, people don't seem too concerned about it: >"[dark matter] seems to make up about 95% of the galactic mass...crushingly narrow passages between observation and tests of GR" GR only matches observation because you added in 20x more stuff that is undetectable other than as a deviation from the predictions of GR. https://news.ycombinator.com/item?id=19537192 https://news.ycombinator.com/item?id=19537192

wyattpeak 8y ago
People aren't worried about it because it doesn't seem like a problem. We know that weakly-interacting matter can exist (as demonstrated by neutrinos), and there's nothing odd about the behaviour of dark matter: it seems to behave exactly as we'd expect weakly-interacting matter to behave. That's certainly not case closed * , but it's plenty to make the explanation perfectly reasonable as a working theory. On a more philosophical level, though, if experts aren't concerned about something, and you as an amateur are, you're almost certainly the one who is wrong. Assume you are, and look for why, rather than questioning their conclusions. It's like the old adage about compiler bugs: they exist, but if you think you've found one, you haven't. * And indeed scientists don't treat it as though it is - there are several other theories, though it's the strongest contender.
- thatoneuser 8y ago
  Id take what you say about amateurs worrying what professionals don't to be true for the most part, but it's also not always true. Even in physics. Iirc about a hundred years ago when we were trying to measure electron diameter, several iterations of scientists bsed there results assuming the last guy was accurate. Dark matter has a lot of similar mysticism and I would not be at all surprised to see a metric shit ton of scientists just being sheep and going along with incorrect models. I'd also not be surprised if they were all spot on too. For reference in grad school I worked in a neutrino lab right by a dark matter lab underground. So I'm not an expert but do have decent exposure.
  - wyattpeak 8y ago
    I didn't say it was always true, I said it was almost certainly true. I stand by that. Untrained amateurs are right from time to time, but given that they have almost no basis for their assumptions except gut feelings, it basically comes down to chance. I'm not arguing that scientists can't be wrong, certainly not. I'm arguing that believing they are, or even believing you have a valid criticism, without understanding on what they base their arguments, because "it sounds reasonable" or "scientists are sheep" is deeply intellectually dishonest.
    - thatoneuser 8y ago
      Right, I didn't mean to sound like I disagree. More like I was making an addendum.
      - wyattpeak 8y ago
        Fair, sorry, probably just a bit tired.
  - chopin 8y ago
    You are referring to the electron charge, not diameter which cannot be measured. Certainly there is bias in physics but I don't recall any occasion where amateurs where correct and experts not (in fundamental physics, that is). This may occur in fringe fields but is highly unlikely in fundamental stuff.
    - thatoneuser 8y ago
      Fair enough, but at the same time dark matter has been around a while and we're no closer to understanding it other than a few ideas about what it isn't. I do think it's a candidate for a very interesting paradigm shift, which there has been before in physics and maybe that's more what I'm getting at. I'll be real I've had a long weekend.
- Tor3 8y ago
  > It's like the old adage about compiler bugs: they exist, but if you think you've found one, you haven't. I'm not sure if that's a good simile. I've found several compiler bugs in my time, and I proved that with assembly output from the compilers and I've received updated compilers from the vendor as a result of my reports. I suspect that to find "bugs" in physical theories must be orders of magnitudes more unlikely.

wyattpeak 8y ago

People aren't worried about it because it doesn't seem like a problem. We know that weakly-interacting matter can exist (as demonstrated by neutrinos), and there's nothing odd about the behaviour of dark matter: it seems to behave exactly as we'd expect weakly-interacting matter to behave. That's certainly not case closed * , but it's plenty to make the explanation perfectly reasonable as a working theory. On a more philosophical level, though, if experts aren't concerned about something, and you as an amateur are, you're almost certainly the one who is wrong. Assume you are, and look for why, rather than questioning their conclusions. It's like the old adage about compiler bugs: they exist, but if you think you've found one, you haven't. * And indeed scientists don't treat it as though it is - there are several other theories, though it's the strongest contender.

thatoneuser 8y ago
Id take what you say about amateurs worrying what professionals don't to be true for the most part, but it's also not always true. Even in physics. Iirc about a hundred years ago when we were trying to measure electron diameter, several iterations of scientists bsed there results assuming the last guy was accurate. Dark matter has a lot of similar mysticism and I would not be at all surprised to see a metric shit ton of scientists just being sheep and going along with incorrect models. I'd also not be surprised if they were all spot on too. For reference in grad school I worked in a neutrino lab right by a dark matter lab underground. So I'm not an expert but do have decent exposure.
- wyattpeak 8y ago
  I didn't say it was always true, I said it was almost certainly true. I stand by that. Untrained amateurs are right from time to time, but given that they have almost no basis for their assumptions except gut feelings, it basically comes down to chance. I'm not arguing that scientists can't be wrong, certainly not. I'm arguing that believing they are, or even believing you have a valid criticism, without understanding on what they base their arguments, because "it sounds reasonable" or "scientists are sheep" is deeply intellectually dishonest.
  - thatoneuser 8y ago
    Right, I didn't mean to sound like I disagree. More like I was making an addendum.
    - wyattpeak 8y ago
      Fair, sorry, probably just a bit tired.
- chopin 8y ago
  You are referring to the electron charge, not diameter which cannot be measured. Certainly there is bias in physics but I don't recall any occasion where amateurs where correct and experts not (in fundamental physics, that is). This may occur in fringe fields but is highly unlikely in fundamental stuff.
  - thatoneuser 8y ago
    Fair enough, but at the same time dark matter has been around a while and we're no closer to understanding it other than a few ideas about what it isn't. I do think it's a candidate for a very interesting paradigm shift, which there has been before in physics and maybe that's more what I'm getting at. I'll be real I've had a long weekend.
Tor3 8y ago
> It's like the old adage about compiler bugs: they exist, but if you think you've found one, you haven't. I'm not sure if that's a good simile. I've found several compiler bugs in my time, and I proved that with assembly output from the compilers and I've received updated compilers from the vendor as a result of my reports. I suspect that to find "bugs" in physical theories must be orders of magnitudes more unlikely.