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One theory of dark matter is that it's strange quark antimatter. An asymmetry in the behavior of quarks and antiquarks in the very early universe would have le

One theory of dark matter is that it's strange quark antimatter. An asymmetry in the behavior of quarks and antiquarks in the very early universe would have led to antiquarks being preferentially squirreled away in tiny ultradense nuggets of quark matter. While explaining dark matter, this would also explain the observed matter-antimatter asymmetry. Or, rather, it would explain it by saying matter and antimatter are present in equal amounts, but the antimatter is in a different form. If this theory were true, tiny nuggets of this antimatter would be passing through the solar system all the time. Perhaps a future society could detect them and somehow trap some for use as an energy source.

lazide 2y ago
For that to be true at the scale required to ‘balance the scales’, we’d have constant annihilation events - which would be impossible to miss.
- pfdietz 2y ago
  Not true: the surface area of the nuggets could be so small they'd fall below detection threshold.
  - lazide 2y ago
    Any interaction with normal matter (including solar wind or the interstellar medium) would result in extremely energetic annihilation events. these aren’t subtle.
    - pfdietz 2y ago
      And if the nuggets have sufficiently small surface area then the rate of these events would be low enough to be obscured by the background from other processes. It would not be like the annihilation from antihydrogen atoms hitting hydrogen atoms. The density of nuclear matter is some 15 orders of magnitude higher than ordinary matter, so nuggets 1 angstrom in diameter could have 10^15 times the mass for a given upper bound on the interaction rate with ambient gas.
      - lazide 2y ago
        There is no way anyone would miss the radiation emitted though. It would be, at a minimum, a very perceptible ‘glow’ over the volumes of space we’re talking about.
        pfdietz 2y ago
        It's not ruled out by evidence, AFAIK, and could explain some observational puzzles. https://indico.fnal.gov/event/6199/contributions/94686/attachments/61845/74173/CF6.pdf https://indico.fnal.gov/event/6199/contributions/94686/attac... (that was 2013; perhaps observations since have made it less likely) 2021 paper: https://arxiv.org/abs/2105.08719 https://arxiv.org/abs/2105.08719 2020 paper: https://www.researchgate.net/publication/342573954_Antimatter_as_macroscopic_dark_matter https://www.researchgate.net/publication/342573954_Antimatte... ("a large region of the parameter space remains unconstrained, most notably for nuclear-dense objects.")

lazide 2y ago

For that to be true at the scale required to ‘balance the scales’, we’d have constant annihilation events - which would be impossible to miss.

pfdietz 2y ago
Not true: the surface area of the nuggets could be so small they'd fall below detection threshold.
- lazide 2y ago
  Any interaction with normal matter (including solar wind or the interstellar medium) would result in extremely energetic annihilation events. these aren’t subtle.
  - pfdietz 2y ago
    And if the nuggets have sufficiently small surface area then the rate of these events would be low enough to be obscured by the background from other processes. It would not be like the annihilation from antihydrogen atoms hitting hydrogen atoms. The density of nuclear matter is some 15 orders of magnitude higher than ordinary matter, so nuggets 1 angstrom in diameter could have 10^15 times the mass for a given upper bound on the interaction rate with ambient gas.
    - lazide 2y ago
      There is no way anyone would miss the radiation emitted though. It would be, at a minimum, a very perceptible ‘glow’ over the volumes of space we’re talking about.
      - pfdietz 2y ago
        It's not ruled out by evidence, AFAIK, and could explain some observational puzzles. https://indico.fnal.gov/event/6199/contributions/94686/attachments/61845/74173/CF6.pdf https://indico.fnal.gov/event/6199/contributions/94686/attac... (that was 2013; perhaps observations since have made it less likely) 2021 paper: https://arxiv.org/abs/2105.08719 https://arxiv.org/abs/2105.08719 2020 paper: https://www.researchgate.net/publication/342573954_Antimatter_as_macroscopic_dark_matter https://www.researchgate.net/publication/342573954_Antimatte... ("a large region of the parameter space remains unconstrained, most notably for nuclear-dense objects.")