John Carlos Baez on Nostr: wrote: "f Bob could see the horizon, at the moment he crossed it, he would see it in ...

wrote:

"f Bob could see the horizon, at the moment he crossed it, he would see it in front of him, overlapping him, and behind him all at once, like an invisible wall passing him at light speed. When Bob crosses the horizon, it appears to him everywhere — like a volume instead of a surface."

I don't quite agree with this. Imagine a line of people walking straight into a nonrotating black hole. When you cross the horizon you see in front of you everyone who already crossed the horizon, and you see them all crossing the horizon the moment your eye crosses the horizon. Their light is moving tangent to the horizon.

But if you look behind you, you see all the people who haven't crossed the horizon yet, and you don't see them *at* the horizon. Their light is moving toward the horizon.

You also see light coming from outside the black hole if you look to your left or your right.

As you cross the horizon, there is only one light ray going through your eye that is tangential to the horizon.

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