• atro_city@fedia.io
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    7 days ago

    In astronomy, dark matter is an invisible and hypothetical form of matter that does not interact with light or other electromagnetic radiation. Dark matter is implied by gravitational effects that cannot be explained by general relativity unless more matter is present than can be observed.

    wikipedia

    Dark matter was posited, in part, because we couldn’t explain how galaxies don’t fling apart due to the rotational forces. Since we observed the effects, but couldn’t see nor detect the cause, we thought something should be there that doesn’t interact with light. However, these findings and that of Caltech show that there isn’t a need for a theoretical matter as normal matter at very low densities will do just fine.

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        7 days ago

        Dark energy is the force believed to drive the expansion of the universe. The distance between galaxies continues to grow and the doesn’t seem to be a good explanation for it yet. It’s the “X” variable acting as a placeholder until that’s answered. Or at least that is my understanding.

        After reading the wikipedia article, that basic understanding of it might be correct, but I’m not an astrophysicist.