From: goldenfieldquaternions@gmail.com   
      
   I answered an outstanding question on the physics stack exchange on page   
   time and information scrambling. Below are the first three paragraphs of   
   the answer.   
      
   The Page time comes about because of the nature of entanglement. For a   
   cavity emitter of black body radiation a photon emitted early on is   
   entangled with atomic states in the cavity. However, once half the   
   energy in the cavity is emitted subsequent radiation emitted is   
   entangled with radiation emitted earlier. As a result the entanglement   
   entropy increases to some maximum, at about half the energy emitted, and   
   then declines. The entangled states are towards the end in the form of   
   emitted radiation.   
      
   A black hole is similar in that Hawking radiation is emitted from an   
   entangled pair of photons or electron positron pairs. One enters the   
   black hole and the other escapes to infinity. At the half way mark,   
   where the black hole has emitted half its mass a conundrum becomes   
   apparent. The black hole continues to build up entanglement entropy by   
   this process. It will exceed the Bekenstein entropy bound. If this is   
   prevented by assuming entanglement of later Hawking radiation is   
   entangled with early Hawking radiation this force bipartite   
   entanglements to evolve into tripartite states, which is not possible by   
   unitary evolution. This is said to violate the monogamy rule. This   
   generally occurs at the so called Page time.   
      
   The idea then is that something catastrophic happens where either   
   unitary evolution or the equivalence principle fails. Preference is   
   given to unitarity, so the equivalence principle is said to fail at the   
   so called firewall.   
      
   Continued at   
      
   https://physics.stackexchange.com/questions/368492/page-time-and   
   black-hole-scrambling-of-information   
      
   LC   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)