Falling into a McVittie Black Hole: A Plunge into an Expanding Waterfall
A waterfall doesn't ask if you're ready to jump. Its flow accelerates, and at some point even light can't escape back. A McVittie black hole is such a waterfall, but not in an ordinary river; it's in an expanding universe: the water here is space itself, which continuously stretches, carrying galaxies apart from each other.