[Pharmakon]

It’s not that interesting unfortunately, although I liked your approach. A graviton would be just another boson like a photon, and like a photon would be unable to escape. All of the worldlines of a graviton within the event horizon would lead to a collision with th singularity. It’s just another aspect of “No Hair” on the hole.

Remember that this applies everything where r≤1. As far as “flat” worldlines I think you might be thinking of a geodesic approaching r=1 in terms of a null geodesic, which isn’t necessarily true unless we’re dealing with a photon or graviton. Regions I,II of the Classic Kruskal-Szekeres extension illustrates this pretty clearly.

https://en.m.wikipedia.org/wiki/Kruskal–Szekeres_coordinates...

The total mass of the black hole (and all other information possible about it) can be described in terms of the boundary at r=1, so there’s no problem with mergers or accretion. To answer Wallace’s original question, we see no information escaping the black hole. What we’re seeing is sort of like shining a light on an absence of information, and observing the shadow cast. That’s not quite right, but it’s close.

[AnimalMuppet]

But there pretty clearly is a gravitational field at r > 1. If that field is made up of gravitons, and a graviton can't escape from the mass to outside r = 1, then what is the source of the gravitons that compose the field at r > 1? If they don't originate at the mass, then... what?

[Pharmakon]

The manifold is well-behaved and continuous at r=1, and mass is one of the few characteristics a black hole has other than spin and charge. Gravitons from within the event horizon won’t escape, but the event horizon itself can be thought of as the entire black hole (for everything outside of the black hole).

This discussion might help where my ability to answer your excellent question is failing: https://physics.stackexchange.com/questions/937/how-does-gra...

[AnimalMuppet]

Thank you for that link - it was very helpful. Summarizing:

The same problem would exist for the electric field from a charged black hole. However, static fields don't need propagating photons to establish them, so you don't have to get photons from inside the black hole in order for the electric field to be established outside.

The same would be true of gravitons. But one respondent indicated that general relativity can't do a second quantization like electromagnetism, and therefore gravitons are... suspect? Impossible? Not proven? It wasn't clear to me how strongly to take that statement.

[wallace_f]

I also saw that stackx discussion when I asked the question and Google'd it. But I was surprised by the fact that while I'd seen in social media, QA, etc this question had been asked before, I was looking for something of a longer or more authoritative source that was accessible to people outside of academic study.

[wallace_f]

I think the downvote brigaiding on this thread is coming from a particular set of users.

I noticed my karma is jumping down in waves. Unrelated comments are all being downvoted at the same time, suggesting unlikely coincidence or that some users are clicking on my profile and going through downvoting all the comments.