Stephen Hawking’s Final Paper: How to Escape from a Black Hole
This is a significantly more... more response than I was expecting, thank you.<p>I do have a couple of quibbles, though:<p>&gt; Hawking radiation converts a pure state into a mixed state. A cryptographic mixing function converts a pure state into a pure state in a way which is hard to trace.<p>This is actually specifically what I meant by &quot;the physics equivalent of&quot;; that is, a quantum-computational mixing function that converts a arbitrary, possibly mixed state to another, probably[0] mixed state, such that a hypothetical extra-physical observer with full knowledge of both states would see the result as uniformly pseudorandom from the range of all possible output states.<p>Also, I take as a sort of provisional axiom[1] that physics is time-reverible (not necessarily symmetric, although probably CPT symmetric) and therefore cannot throw away or generate new any (quantum mechanical&#x2F;qubit-based, so orthogonal-basis measurements aren&#x27;t) information. (Given this and something like the Bekenstein bound, that a evaporating black hole must be leaking its information to somewhere, and its radiation must be <i>getting</i> its information content from somewhere, are seemingly trivial.)<p>0: In the thermodynamics&#x2F;statistical mechanics &quot;almost certainly&quot; sense.
1: similar to and as serious as Conservation of Energy or &quot;Scientists are made out of atoms and cannot cause magical non-(unitary&#x2F;linear&#x2F;differentiable&#x2F;local&#x2F;CPT symmetric&#x2F;Liouville uniform&#x2F;deterministic&#x2F;etc) events by looking at things.&quot;