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Shades of grey

J. Harry Caufield

(Or maybe shades of gray, depending on where you are in space and what you're wearing.)

Stephen Hawking has proposed that black holes may not be what we think they are. That is, they aren't black. Or maybe not holes. Either way, Hawking has long had an issue with what happens to information and energy when it enters a black hole. It's a thorny issue which the above article handles much more aptly than anything I could discuss, so here are some summary quotes:
In place of the event horizon, Hawking invokes an “apparent horizon”, a surface along which light rays attempting to rush away from the black hole’s core will be suspended. In general relativity, for an unchanging black hole, these two horizons are identical, because light trying to escape from inside a black hole can reach only as far as the event horizon and will be held there, as though stuck on a treadmill. However, the two horizons can, in principle, be distinguished. If more matter gets swallowed by the black hole, its event horizon will swell and grow larger than the apparent horizon.
Conversely, in the 1970s, Hawking also showed that black holes can slowly shrink, spewing out 'Hawking radiation'. In that case, the event horizon would, in theory, become smaller than the apparent horizon. Hawking’s new suggestion is that the apparent horizon is the real boundary. “The absence of event horizons means that there are no black holes — in the sense of regimes from which light can't escape to infinity,” Hawking writes.
This doesn't make black holes - or whatever the best term for them is - nicer places to visit. Even if energy/information entering them isn't destroyed, it's still dispersed and disrupted. Hawking ends his brief paper on the subject with
One can’t predict the weather more than a few days in advance.