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MiffedMouse t1_j349be8 wrote

Reply to comment by mfb- in How do galaxies move? by modsarebrainstems

The ant on a rubberband example does not work for the universe. Even if the Hubble constant was constant with time, the universe expands exponentially, not linearly (so the “universe” rubberband length goes 1,2,4,8; not 1,2,3,4). An ant on an exponentially growing rubberband cannot reach everywhere.

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mfb- t1_j34a80w wrote

For the past 10 billion years a linear expansion was a pretty decent approximation. The early universe slowed its expansion, which makes the relative reach of the ant even larger (or, equivalently, the early recession speeds were larger).

The Hubble rate is still decreasing. It's expected to approach a constant in the future. I covered that in the second paragraph:

> In the distant future, in a universe completely dominated by dark energy, your statement will be right.

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