• rbesfe
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    5 months ago

    Dark matter isn’t based on simulations, it’s entirely observational.

    We observe here that matter generates a gravitational force proportional to the amount of matter present, and we know that to an extreme degree of precision, but when we look at big things like galaxies the force required to shape and move them in the ways we observe would require more matter than we observe within them.

    • Sonori@beehaw.org
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      5 months ago

      To expand on this, we also have mapped it out and know that the amount of dark matter varies wildly between galaxies, with some having basically none while others have far more dark matter than observable matter in them. There’s also a lot of stuff with the early universe that only works if you have something with gravity that doesn’t otherwise interact significantly with matter.

      As Angela Collier puts it, dark matter is not a theory, it is a set of observations.