That makes sense. I said something else would make no sense:
"If you're wishing he'd graphed the "distance" between the two ships to see if they get "bunched up" when they approach the horizon, think about why that MAKES NO SENSE!"
If you're not wishing that, then never mind - as long as you see why it makes no sense.
When you spoke of ships "bunching up near the horizon", I wasn't sure what that was supposed to mean. It's actually a bit hard to define "bunching up" in terms of what Bob sees. He'll see the closest ship, and it will block the view of ships behind that one. If he moves up a bit to see the other ships, they will bunch up angularly in his field of view - but they'd do that even if you had equally spaced ships in flat spacetime (see photo below). So maybe you're asking if they bunch up "more than that". Or maybe we should compute the angular size of each ship as it would be seen without closer ships blocking it.
Anyway, I believe nothing amazingly different happens at the moment Bob crosses the horizon. I believe that right before this moment, at this moment, and after it, if he pokes his head up he'll see a line of ships stretching off in the distance in front of him, with smaller and smaller angular sizes, and increasingly redshifted.
Greg Egan (npub12cu…d38p)
