A black hole is not an absolutely black bag. In 1974, Stephen Hawking showed that it glows — faintly, but continuously. This radiation is born not inside, but outside, right at the boundary from which even light cannot escape.
A new study sharpens the picture. The researchers calculated how a simple wave scatters off the curved spacetime of a black hole. It turns out that outside there are special states — neither bound nor free, like a ball stuck in the bushes at the edge of a pit. These states form a hot 'atmosphere' with the Hawking temperature.
This approach doesn't yield new numbers, but it connects radiation with the ordinary physics of hot gas. The atmosphere behaves like steam above boiling water — except here, the water is spacetime itself.
If a black hole with the mass of the Sun were placed in empty space, its temperature would be a hundred million times colder than the cosmic microwave background: it would be an icy dot in the middle of the cosmos.
In Dan Simmons' novel 'Hyperion,' the Time Tombs are surrounded by an anti-entropic field that warps time — what is that if not a quantum atmosphere of a black hole?