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Dark matter worlds

  1. Oct 22, 2014 #1


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    It seems like most sci-fi hasn't really touched much upon dark matter. Instead of making up all sorts of fantastical new dimensions or universes, why not focus on dark matter, something we legitimately don't understand and really exists?

    There's far more dark matter than baryonic matter. Is it possible that dark matter interacts with dark matter, and can form complex structures, maybe even worlds of dark matter? And maybe even creatures on those worlds, who live in a completely alien environment, which we can't see but they can. And they likewise cannot see us, except through gravity. They would experience almost totally different laws of physics, but, actually be part of our same universe.
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  3. Oct 22, 2014 #2
    A quote from my professor: "If you don't understand something, you tend to assign any property or quality to it". I have legitimately never heard of the idea of dark matter actually interacting with itself to form complex structures. That's mind-boggling, and creative.
  4. Oct 22, 2014 #3


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    Why do you think they would experience anything different in terms of the laws of physics while still a part of the same universe. Now there IS a mind boggling idea (totally unrealistic though, to the point of being silly if you think about it scientifically).
  5. Oct 22, 2014 #4
    Obviously it obeys gravity, but everything should since it's a property of space-time itself, not the matter.
  6. Oct 23, 2014 #5


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    By different physics, I mean they would interact via different, undiscovered forces. They wouldn't form atoms or molecules, but something else. They would still feel gravity, and obey causality and thermodynamics, but so much would be different.

    We know that galaxies are composed of both normal and dark matter, but the distribution of dark matter is different. Perhaps the "range" of dark matter interactions forces is large, so the "molecules" are the size of planets, and complex structures exist on much larger scales, so the creatures who live in this environment are truly giant compared to us. The age of the universe puts some constraints on the size of a complex interacting system, since dark matter is presumably still limited by the speed of light, so creatures probably couldn't be the size of galaxies, but maybe the size of stars.

    Of course this is all very speculative, because we really don't know enough about dark matter to build much upon. We don't even know if it's cold or hot, which would have some profound influence on the structure formation.
  7. Oct 23, 2014 #6

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    We know DM does not clump. That severely restricts the sort of structures it can form.
  8. Oct 27, 2014 #7


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    It's not well understood enough to make it part of most settings and what is known about it makes things difficult. Essentially an author would have to make so much up that they might as well make up something entirely new. This also avoids the problem of longevity, once a book is published that's it, generally there are no more revisions. As an author you want your books to be readable for a long time which isn't going to happen if a few years after publishing a new set of dark matter data blows your world building out of the water.
  9. Oct 27, 2014 #8
    Maybe nobody wants to compete against Stephen Baxter's Xeelee Sequence.
  10. Nov 16, 2014 #9
    Dark matter interacts only VERY weakly with ordinary matter, and apparently VERY weakly with itself also. So there isn't much that one can do with it.

    But I've seen various theoretical speculations about "parallel matter" or "shadow matter" or "mirror matter", so one could have fun with such speculations. Such matter would interact only very weakly with Standard-Model matter, however.
  11. Sep 9, 2015 #10
    I almost started a topic with the same question but I see that someone had the same though already a while ago.

    I've got the following question for ignored dark matter for SF purposes. Could it be used to build a dozen of alternative dimension? (I use dimension in the SF meaning, when it means some other world) Which under normal conditions only interact weakly through gravity with normal matter? And do it in very indirect way? When all those interactions from dimensions are combined together the impression is that such matter do not clump together.

    No, the question is not whether this wild idea is correct, but whether it already contradicts some experimental data or are we going soon to get good enough data to contradict it?
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