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the lowest mass dark object currently measured one million times the mass of the Sun Sometimes you read things that remind you how vast and untamable our un

the lowest mass dark object currently measured one million times the mass of the Sun Sometimes you read things that remind you how vast and untamable our universe really is.

deleted 1y ago
[deleted]
catigula 1y ago
If you think that's crazy, it's likely a drop in the bucket comared to the noumenonal world. There's no reason to think that our senses encompass the vast majority of understanding everything in reality and current evidence that they, in fact, do not, via dark matter as a primary source. I suspect our senses encompass a meaningless fraction of the noumenon.
- procflora 1y ago
  In what way is dark matter not a phenomenon? Just because we don't know what it is doesn't make it a noumenon.
  - catigula 1y ago
    It's that it demonstrates that some sort of noumenon can likely have partial but not 'full' overlap as we understand it with a phenomenon. To elaborate, the noumenon can have properties that are unknown to us and outside the purview of certain senses (if not all) but still have partial phenomenal effects such as gravitational effects. Given partial overlap, we could, and likely should, surmise that overlap, if partial, can also be zero. In fact, partial overlap with certain things (such as the gravitational field) but no sensory experience is exactly what we'd predict if this were true. The mistake is thinking I'm asserting that things are phenomenon or noumenon when that's not quite right. Mostly, the supposition is that things can exist and have either 'full' (unlikely I think), partial, or zero overlap with our sensory experience. Things that demonstrably have partial overlap suggest a wider world of things. I simply find the idea that our evolved sensory experience encompass even a sizable fraction of reality to lack epistemic humility. This is obviously speculative.
    - throwway120385 1y ago
      A good example of this would be the scope of our sense of sight as it relates to the entire electromagnetic spectrum. We can't see things like UV or Gamma radiation, we can only infer their existence by their effect on things we can see. The reality is that those phenomena might not actually exist in any perceivable way. The only thing we know, strictly speaking, is that the effect happens, and we have a plausible mental model for why the effect happens that predicted other effects that we also observe. But we can't prove that the mental model is reality. This is at the heart of the Allegory of The Cave: https://en.wikipedia.org/wiki/Allegory_of_the_cave https://en.wikipedia.org/wiki/Allegory_of_the_cave. What we're discussing is a kind of "Natural Philosophy" or Physics, the study of that which is.
_joel 1y ago
Yep, this still blows my mind, has a radius of 330 million light years, of, er, nothing (well 60 galaxies compared to what should be several thousand). https://en.wikipedia.org/wiki/Bo%C3%B6tes_Void https://en.wikipedia.org/wiki/Bo%C3%B6tes_Void
- bobmcnamara 1y ago
  sssh, that's where we store the hammers
GuB-42 1y ago
I think there is a shortcut being taken here. We are surrounded by dark objects, a rock is a dark object, exoplanets are dark objects, and so are black holes. Pretty much everything but stars are dark objects. They are all dark because they don't emit light. Here, I think they mean stuff (whatever it is) that can only be detected by gravitational lensing, and it makes sense that it has to be extremely heavy, because gravity is so weak.
- RogerL 1y ago
  I'm not a physicist but every definition of dark matter that I read says it does not interact with electromagnetic radiation hence it is invisible, and rocks are not that dark matter (wiki. NASA, etc)
  - lutusp 1y ago
    > ... every definition of dark matter that I read says it does not interact with electromagnetic radiation ... Actually, dark matter does interact with electromagnetic radiation -- it can deflect it, as in the case of gravitational lensing. But dark matter doesn't either emit nor absorb electromagnetic radiation directly. We only know about dark matter because of its gravitational effects.
    - GuB-42 1y ago
      How about stellar mass black holes? They are much lighter than 1 million solar masses and we know a few of them, with a variety of ways to detect them, including companion stars orbiting around them and gravitational waves during mergers. Black holes fit the definition of dark matter, as they neither emit nor absorb electromagnetic radiation, not in a way that could be detected anyways. This is the "MACHO" theory of dark matter, which is not the favorite, but it is still taken seriously. Stellar mass black holes have been ruled out, I think, but it doesn't mean dark matter can't be made of black holes. In fact, primordial black holes are a rather hot theory.
      - lutusp 1y ago

the lowest mass dark object currently measured one million times the mass of the Sun Sometimes you read things that remind you how vast and untamable our universe really is.

deleted 1y ago

[deleted]

catigula 1y ago

If you think that's crazy, it's likely a drop in the bucket comared to the noumenonal world. There's no reason to think that our senses encompass the vast majority of understanding everything in reality and current evidence that they, in fact, do not, via dark matter as a primary source. I suspect our senses encompass a meaningless fraction of the noumenon.

procflora 1y ago
In what way is dark matter not a phenomenon? Just because we don't know what it is doesn't make it a noumenon.
- catigula 1y ago
  It's that it demonstrates that some sort of noumenon can likely have partial but not 'full' overlap as we understand it with a phenomenon. To elaborate, the noumenon can have properties that are unknown to us and outside the purview of certain senses (if not all) but still have partial phenomenal effects such as gravitational effects. Given partial overlap, we could, and likely should, surmise that overlap, if partial, can also be zero. In fact, partial overlap with certain things (such as the gravitational field) but no sensory experience is exactly what we'd predict if this were true. The mistake is thinking I'm asserting that things are phenomenon or noumenon when that's not quite right. Mostly, the supposition is that things can exist and have either 'full' (unlikely I think), partial, or zero overlap with our sensory experience. Things that demonstrably have partial overlap suggest a wider world of things. I simply find the idea that our evolved sensory experience encompass even a sizable fraction of reality to lack epistemic humility. This is obviously speculative.
  - throwway120385 1y ago
    A good example of this would be the scope of our sense of sight as it relates to the entire electromagnetic spectrum. We can't see things like UV or Gamma radiation, we can only infer their existence by their effect on things we can see. The reality is that those phenomena might not actually exist in any perceivable way. The only thing we know, strictly speaking, is that the effect happens, and we have a plausible mental model for why the effect happens that predicted other effects that we also observe. But we can't prove that the mental model is reality. This is at the heart of the Allegory of The Cave: https://en.wikipedia.org/wiki/Allegory_of_the_cave https://en.wikipedia.org/wiki/Allegory_of_the_cave. What we're discussing is a kind of "Natural Philosophy" or Physics, the study of that which is.

_joel 1y ago

Yep, this still blows my mind, has a radius of 330 million light years, of, er, nothing (well 60 galaxies compared to what should be several thousand). https://en.wikipedia.org/wiki/Bo%C3%B6tes_Void https://en.wikipedia.org/wiki/Bo%C3%B6tes_Void

bobmcnamara 1y ago
sssh, that's where we store the hammers

GuB-42 1y ago

I think there is a shortcut being taken here. We are surrounded by dark objects, a rock is a dark object, exoplanets are dark objects, and so are black holes. Pretty much everything but stars are dark objects. They are all dark because they don't emit light. Here, I think they mean stuff (whatever it is) that can only be detected by gravitational lensing, and it makes sense that it has to be extremely heavy, because gravity is so weak.

RogerL 1y ago
I'm not a physicist but every definition of dark matter that I read says it does not interact with electromagnetic radiation hence it is invisible, and rocks are not that dark matter (wiki. NASA, etc)
- lutusp 1y ago
  > ... every definition of dark matter that I read says it does not interact with electromagnetic radiation ... Actually, dark matter does interact with electromagnetic radiation -- it can deflect it, as in the case of gravitational lensing. But dark matter doesn't either emit nor absorb electromagnetic radiation directly. We only know about dark matter because of its gravitational effects.
  - GuB-42 1y ago
    How about stellar mass black holes? They are much lighter than 1 million solar masses and we know a few of them, with a variety of ways to detect them, including companion stars orbiting around them and gravitational waves during mergers. Black holes fit the definition of dark matter, as they neither emit nor absorb electromagnetic radiation, not in a way that could be detected anyways. This is the "MACHO" theory of dark matter, which is not the favorite, but it is still taken seriously. Stellar mass black holes have been ruled out, I think, but it doesn't mean dark matter can't be made of black holes. In fact, primordial black holes are a rather hot theory.
    - lutusp 1y ago