The reason I have been absent from this thread for a while is not lack of interest.

your link: http://phys.org/news/2011-03-black-holes.html starts with a mention of Hawking radiation. In principle I know what it is, but one thing that puzzles me is that the event horizon of a BH is always presented as a zone in which conditions change slowly. Hawking radiation seems to require it to be a surface of such precise location that it can separate something as closely spaced as a particle/antiparticle pair. What am I missing?

There never was nothing.