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by _madmax_ 1028 days ago
>However, for the past ~6 billion years, distant galaxies have been speeding up in their recession, and the expansion rate, though still dropping, is not headed toward zero.

Am I not getting something here or is this sentence not make sense?

4 comments

It makes sense if the expansion rate isn't dropping linearly and the rate of the drop is itself dropping towards zero.
The rate of acceleration is slowing down, but still is accelerating.
So the first derivative was already understood to remain nonzero forever[1], now we know that the second derivative probably will also remain nonzero, and the third is slowing down but still positive for the moment?

[1] IIRC in the 80s the big bang/big crunch model was preferred

The slowing down is speeding up. What could be simpler?