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[deleted] t1_isjvp36 wrote

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autoposting_system t1_isk1a57 wrote

So there's a point when two objects stop pulling on each other if they're moving apart at greater than light speed due to the expansion of space?

Does this account for the increasing rate of expansion? The decreasing effect of gravity?

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Ape_Togetha_Strong t1_isk9xkm wrote

The rate of expansion is not increasing. It increases with distance, so individual objects have an increasing rate of expansion over time but "the rate of expansion of the universe" is not increasing.

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autoposting_system t1_iskeush wrote

I'm sorry, I'm not following you. What's the difference? The rate at which objects at opposite edges of the visible universe move apart is increasing, yes?

I am a layman, sorry

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Ape_Togetha_Strong t1_iskio0k wrote

Well, they're different because they are entirely different things. The fact that the rate increases for specific objects moving away from us is a consequence of the fact that the rate of expansion increases with distance. That's just not the same as the rate of expansion, 73ish km/s/mpc, increasing over time.

>The rate at which objects at opposite edges of the visible universe move apart is increasing, yes?

This is a weird way to think about the expansion. It's only true because the size of the observable universe is also increasing, since it's limited by the age of the universe, not distance. If instead of "at opposite edges of the visible universe" you just say "at the same specified distance apart", then that does not increase.

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Usedtodrum t1_isjx78p wrote

If this were true wouldn't this contradict the final parsec problem with black holes?

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[deleted] t1_isjyly2 wrote

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Usedtodrum t1_iskrvb2 wrote

Hmm, I thought the issue was that there wasn't enough material left between them to 'eat up' thus making it impossible for them to attract each other and merge.

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