Video Transcription
If an object passes through the event horizon of a black hole, all the information about that object becomes part of the black hole itself.
Once they've fallen in, all you can see is a heavier black hole, and you don't know what fell in if you weren't watching it.
Well, that doesn't ******* the laws of physics, but if the black hole continues to evaporate, evaporate, evaporate with thermal radiation,
and then disappear, then all you have afterwards is thermal radiation. You have no information, even in principle, about what fell in.
And that information is precisely what quantum mechanics says can't be lost.