4 ms·

This article is new (just one-two weeks ago) but the latest research based on is from 4 years ago. Poor choice because few months ago a study (https://journals.

This article is new (just one-two weeks ago) but the latest research based on is from 4 years ago. Poor choice because few months ago a study (https://journals.aps.org/prd/abstract/10.1103/PhysRevD.107.103021 https://journals.aps.org/prd/abstract/10.1103/PhysRevD.107.1...) reopened the possibility of being dark matter afterall.

perihelions 3y ago
If I understand that paper, it's still the case that there's zero evidence for dark matter annihilation from AMS positrons. What it says it that (a certain type of) such evidence could, in principle, exist—it contradicts a previous theory conclusion that dark matter and pulsar positrons would have indistinguishable energy spectra. I.e. the OP blogpost is still completely accurate. (??) (Of course—just to clarify if we all have a shared understanding—nothing in OP rules out the possibility of dark matter annihilation; it just says there's no evidence for it currently in AMS positrons. And to clarify shared understanding of a different point—the OP research isn't about positron energy spectrum features; it's a separate question about their total luminosity. The intro section of your paper discusses the distinction: "In addition to energetic arguments, the positron spectrum has long been discussed...")
xqcgrek2 3y ago
Dark matter people can always wiggle out of any non-detection or standard physics models by adding more parameters. They've been doing this for 40 years and at this point it's just sad and pathological science.
- empyrrhicist 3y ago
  Such a brave take, you must be some sort of freethinking renegade, ostracised by the deep physics conspiracy.
  - Ma8ee 3y ago
    Or maybe it is just true, and worth pointing out, whenever dark matter is brought up as something else than the hypothetical explanation it is. That snark doesn’t belong here.
    - empyrrhicist 3y ago
      No, the conspiracy doesn't belong here. There's a vibrant mainstream world trying to pin down or disprove dark matter, but there's a phenotype of cynic that's really common here on HN that precisely deserves the snark - low effort comments dismissing mainstream research while clearly not understanding it.
      - Ma8ee 3y ago
        I think that mainstream research in physics has lost a lot of credibility after spending decades pursuing things like string theories and super symmetry. Not that it was anything wrong with any of those at first, but they weren't presented as hypotheses, they dominated research way too much, and it took way to long to admit they were dead ends (most still haven't, but instead silently started working on different stuff).
        empyrrhicist 3y ago
        Broad brush much? You're also completely ignoring the difference between experimental and theoretical physics, which... both have a lot of things to say about the search for dark matter. Like... sure, no field is perfect, but saying that a whole gigantic collection of specialties has "lost a lot of credibility" after one particular mathematical framework took up (in your opinion) too much oxygen strikes me as lazy and not particularly useful. So - why does this add to the discussion? How would I be better served by focusing on your disappointment than trying to learn what actual researchers are saying and doing? Why should I trust in the cynicism of HN comments when I can go read about what experts are actually focusing on/debating/excited about? There's so much new data coming in these days, pedantic "skeptics" just strike me as increasingly annoying and useless.

perihelions 3y ago

If I understand that paper, it's still the case that there's zero evidence for dark matter annihilation from AMS positrons. What it says it that (a certain type of) such evidence could, in principle, exist—it contradicts a previous theory conclusion that dark matter and pulsar positrons would have indistinguishable energy spectra. I.e. the OP blogpost is still completely accurate. (??) (Of course—just to clarify if we all have a shared understanding—nothing in OP rules out the possibility of dark matter annihilation; it just says there's no evidence for it currently in AMS positrons. And to clarify shared understanding of a different point—the OP research isn't about positron energy spectrum features; it's a separate question about their total luminosity. The intro section of your paper discusses the distinction: "In addition to energetic arguments, the positron spectrum has long been discussed...")

xqcgrek2 3y ago

Dark matter people can always wiggle out of any non-detection or standard physics models by adding more parameters. They've been doing this for 40 years and at this point it's just sad and pathological science.

empyrrhicist 3y ago
Such a brave take, you must be some sort of freethinking renegade, ostracised by the deep physics conspiracy.
- Ma8ee 3y ago
  Or maybe it is just true, and worth pointing out, whenever dark matter is brought up as something else than the hypothetical explanation it is. That snark doesn’t belong here.
  - empyrrhicist 3y ago
    No, the conspiracy doesn't belong here. There's a vibrant mainstream world trying to pin down or disprove dark matter, but there's a phenotype of cynic that's really common here on HN that precisely deserves the snark - low effort comments dismissing mainstream research while clearly not understanding it.
    - Ma8ee 3y ago
      I think that mainstream research in physics has lost a lot of credibility after spending decades pursuing things like string theories and super symmetry. Not that it was anything wrong with any of those at first, but they weren't presented as hypotheses, they dominated research way too much, and it took way to long to admit they were dead ends (most still haven't, but instead silently started working on different stuff).
      - empyrrhicist 3y ago
        Broad brush much? You're also completely ignoring the difference between experimental and theoretical physics, which... both have a lot of things to say about the search for dark matter. Like... sure, no field is perfect, but saying that a whole gigantic collection of specialties has "lost a lot of credibility" after one particular mathematical framework took up (in your opinion) too much oxygen strikes me as lazy and not particularly useful. So - why does this add to the discussion? How would I be better served by focusing on your disappointment than trying to learn what actual researchers are saying and doing? Why should I trust in the cynicism of HN comments when I can go read about what experts are actually focusing on/debating/excited about? There's so much new data coming in these days, pedantic "skeptics" just strike me as increasingly annoying and useless.