The Gravity program I watched brought something really interesting to my awareness. With black-hole Hawking radiation... everything gets sucked into the event horizon... we don't know what happens there... if the material is lost forever. What we theorize is that over time the black hole evaporates. With the speed of light being the limit of information transmission, propagating causality, energy/mass transfer... since the gravitational force distorts space-time to such an extent that not even light can escape this region. So where does this information (a word I really enjoy) go when the black hole is evaporated?

The program goes on to communicate that this is no different than the burning of an encyclopedia. When the matter burns... all information contained in it is irreversibly lost. But to me... it seems different. The burning of a book has chemical reactions that take place with the ink of the paper... but black holes store such a practically infinite amount of information within the center. Seems like such behavior would be insanely more complex. Can anyone explain this topic or point me in the right direction?

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    $\begingroup$ Which program told you that information is lost when you burn a book? That’s not true. It’s not practical to reconstruct from the smoke and ashes, but it isn’t lost. $\endgroup$
    – G. Smith
    Aug 25, 2020 at 21:44
  • $\begingroup$ I'm not sure I'm presenting it correctly... I'm a Computer Scientist by training... so my terminologies are different. But the data contained in the book... the text... is lost... converted to something else that's no longer translatable. $\endgroup$
    – Shay Maor
    Aug 25, 2020 at 21:46
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    $\begingroup$ They did however put an emphasis on "practically" speaking when mentioning the information is lost. $\endgroup$
    – Shay Maor
    Aug 25, 2020 at 22:22
  • $\begingroup$ I thought the gravitational center was where the singularity took place and would exert an attractive force due to distortion of space time to force all information within this infinitely small and infinitely dense space. I havent read that the information is stored in the event horizon. $\endgroup$
    – Shay Maor
    Aug 25, 2020 at 23:26
  • $\begingroup$ Thanks for elaborating. Very interesting. I'll do more digging. $\endgroup$
    – Shay Maor
    Aug 25, 2020 at 23:36

1 Answer 1


The "famous" information paradox. See here for more INFORMATION... Exactly this question resulted in "The Black Hole War", a book written by Leonard Susskind. After making a bet with Stephen Hawkins, it was finally concluded that Susskind (and van 't Hooft) were right and got a bottle of champagne (though the debate is still going on).
The question is indeed much more complicated than burning a book, after which it's in principle possible to retrieve all the information.
The difficulty is due to the fact that one has to use both quantum mechanics and general relativity. Susskind and others developed the ADS/CFT (anti-de Sitter Space/Conformal Field Theory) correspondence meant to make the paradox easier to grasp. This correspondence though is based on string theoretical methods, but string theory is still what it is: a theory. So the ADS/CFT can't be taken too seriously.

Due to this, the problem is, in fact, not resolved. It's not before a fully-fledged theory of quantum gravity is found (which I doubt because it's not even sure if GR can be quantized), that the paradox can be resolved.


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