A particle has just entered a minuscule (and non-rotating) black hole which is at the end of its life. The black hole is getting smaller really fast as it boils away ejecting tonnes of Hawking radiation. Couldn't the particle come back out of the event horizon as the event horizon gets closer to the singularity? Wouldn't the event horizon pass the particle once more as the Schwarzschild radius diminishes? Or is it that the whole sphere would shrink uniformly so that the particle just gets closer to the singularity?

I think the space-time near the event horizon would stop being curved inwards and let the particle escape.

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    – ACuriousMind
    Commented Aug 23, 2020 at 16:41

1 Answer 1


As long as there is an EH, nothing escapes.

In your case, the fast shrinking BH might be fast, but it will never shrink faster then the speed of light, but that does not even matter. This question is about curvature.

Inside the EH, there is extreme curvature, and the real reason why nothing escapes it is the escape velocity, being excess of c.

No, once a black hole forms there's no turning back. It can lose mass via Hawking radiation, but (as far as we know) it cannot stop being a black hole until there's nothing left. There's no theoretical lower mass limit for a black hole.

When we are talking about black hole evaporation - what exactly happens?

Now as long as there is an EH, inside it the escape velocity exceeds c, and thus nothing escapes.


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