It from QBit

  • Information, Physics, Quantum, Wheeler’s 1989 essay propounding the idea that the physical universe arises from information, which he dubbed “it from bit.”
    • ESSAY: http://cqi.inf.usi.ch/qic/wheeler.pdf
  • https://arxiv.org/pdf/1306.0545.pdf
    • reading the autobiography of Wheeler, it seems that the scientist has in-
      tended a vision more materialistic than that of Bohr, in which these bits would be true “quanta of reality”: “I suggest that we may never understand this strange thing, the quantum, until we understand how information may underlie reality. Information may not be just what we ‘learn’ about the world. It may be what ‘makes’ the world. An exam- ple of the idea of it from bit: when a photon is absorbed, and thereby ‘measured’ – until its absorption, it had no true reality – an unsplittable bit of information is added to what we know about the world, ‘and’, at the same time, that bit of information determines the
      structure of one small part of the world. It ‘creates’ the reality of the time and place of that photon’s interaction.”
  • https://arxiv.org/pdf/1311.0765.pdf
    • The main mystery of quantum mechanics is contained in Wheeler’s
      delayed choice experiment, which shows that the past is determined by our
      choice of what quantum property to observe. This gives the observer a par-
      ticipatory role in deciding the past history of the universe. Wheeler extended
      this participatory role to the emergence of the physical laws (law without
      law). Since what we know about the universe comes in yes/no answers to
      our interrogations, this led him to the idea of it from bit (which includes the
      participatory role of the observer as a key component).
      The yes/no answers to our observations (bit) should always be compatible
      with the existence of at least a possible reality – a global solution (it) of the
      Schr¨odinger equation. I argue that there is in fact an interplay between it
      and bit. The requirement of global consistency leads to apparently acausal
      and nonlocal behavior, explaining the weirdness of quantum phenomena.
      As an interpretation of Wheeler’s it from bit and law without law, I discuss
      the possibility that the universe is mathematical, and that there is a “mother
      of all possible worlds” – named the Axiom Zero.
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A Physicist’s Physicist Ponders the Nature of Reality

ref: https://www.quantamagazine.org/edward-witten-ponders-the-nature-of-reality-20171128/

  • Information, Physics, Quantum, Wheeler’s 1989 essay propounding the idea that the physical universe arises from information, which he dubbed “it from bit.”
  • “it from qubit.”
  • I tend to assume that space-time and everything in it are in some sense emergent.
  • He drew a picture on the blackboard of the universe visualized as an eye looking at itself. I had no idea what he was talking about. It’s obvious to me in hindsight that he was explaining what it meant to talk about quantum mechanics when the observer is part of the quantum system. I imagine there is something we don’t understand about that.