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Infernalism t1_j9rxlp6 wrote

You can use the old 'balloon' analogy.

Take a balloon and mark a bunch of dots on the outside of the balloon. Then blow it up.

As you blow it up, the dots expand away from each other, but they're not actually moving, are they? It's the fabric of the balloon stretching.

Likewise, the fabric of space is expanding and stretching. Dark matter is what keeps galaxies connected to each other through this expanding, but the galaxies are spreading apart from each other.

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PyrorifferSC t1_j9s6pxo wrote

Does that actually increase the distance between bodies of mass though?

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Infernalism t1_j9s73pg wrote

Between galaxies? yes. But something about the dark matter keeps galaxies coherent and condensed rather see the stars within those galaxies spread apart.

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PyrorifferSC t1_j9s99qo wrote

Gooootcha yeah I remember that now. I knew there was some caveat about stars not separating from each other, that makes a lot of sense. Thank you!

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