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What is a black hole, and what would happen if you fell in? (for a curious adult who has not studied physics). Cover, in this order: What is a black hole?; How can gravity be strong enough to trap light?; How does a black hole form?; What is the event horizon?; What happens if you fall into a black hole?; If nothing escapes, how do we see black holes?; Do black holes really suck everything in?; Can a black hole die? — page 8: Can a black hole die?
We said nothing escapes. So how could a black hole die? Quantum physics adds a loophole, and Hawking found it in 1974.
Picture a pair of particles popping up right at the edge. One falls in, one flies off. That escaping particle carries energy away.
Energy is mass. Every escaped particle makes the black hole a tiny bit lighter. It is slowly spending itself, like an ember cooling.
A star-sized black hole is colder than the space around it, so for now it absorbs more heat than it gives off, and the glow stays faint.
As it shrinks, it glows hotter and leaks faster, ending in a burst. For real black holes, that takes far longer than the universe has existed.
Two forces fight over a black hole: swallowed matter makes it grow, while Hawking radiation makes it shrink. Today growth wins; shrinking takes over only in the far future.
So even gravity's greatest trap is not forever: black holes glow faintly, shrink slowly, and in an almost endless future, they fade away.