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Does nature impose limits on what we can know? But why?

From an article in Nature, on a variety of efforts to come to terms with the quantum world:

… entanglement and all the other strange phenomena of quantum theory are not a completely new form of physics. They could just as easily arise from a theory of knowledge and its limits.

To get a better sense of how, Fuchs has rewritten standard quantum theory into a form that closely resembles a branch of classical probability theory known as Bayesian inference, which has its roots in the eighteenth century. In the Bayesian view, probabilities aren’t intrinsic quantities ‘attached’ to objects. Rather, they quantify an observer’s personal degree of belief of what might happen to the object. Fuchs’ quantum Bayesian view, or QBism (pronounced ‘cubism’), is a framework that allows known quantum phenomena to be recovered from new axioms that do not require mathematical constructs such as wavefunctions. QBism is already motivating experimental proposals, he says. Such experiments might reveal, for example, new, deep structures within quantum mechanics that would allow quantum probability laws to be re-expressed as minor variations of standard probability theory.

Knowledge — which is typically measured in terms of how many bits of information an observer has about a system — is the focus of many other approaches to reconstruction, too. As physicists Caslav Brukner and Anton Zeilinger of the University of Vienna put it, “quantum physics is an elementary theory of information”. Meanwhile, physicist Marcin Pawlowski at the University of Gdansk in Poland and his colleagues are exploring a principle they call ‘information causality’. This postulate says that if one experimenter (call her Alice) sends m bits of information about her data to another observer (Bob), then Bob can gain no more than m classical bits of information about that data — no matter how much he may know about Alice’s experiment.

Well, if a theory of information underlies the universe, then intelligence must also, not?

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3 Responses to Does nature impose limits on what we can know? But why?

  1. Anyone not familiar with the writings of Stanley L. Jaki could not harm themselves by reading everything he’s written that they can get their grubby little hands on.

    Knowledge — which is typically measured in terms of how many bits of information an observer has about a system … if one experimenter (call her Alice) sends m bits of information about her data to another observer (Bob)…

    Ah yes, the aboutness of information.

  2. 2

    OT: “Functioning ‘mechanical gears’ seen in nature for the first time”

    This could be up there with the bacterial flagellum as an icon of ID.

    http://phys.org/news/2013-09-f.....ature.html

  3. As to this comment from the article:

    “What is it about this world that forces us to navigate it with the help of such an abstract entity?” wonders physicist Maximilian Schlosshauer of the University of Portland in Oregon, referring to the uncertainty principle; the wave function that describes the probability of finding a system in various states;,,
    Over the past decade or so, a small community of these questioners have begun to argue that the only way forward is to demolish the abstract entity and start again.,,
    his larger goal was to show how quantum physics might be reframed as a general theory of probability.,,

    Two problems with their proposal. One problem is that the infinite dimensional wave-function is not an ‘abstract’ entity but is real:

    On the reality of the quantum state – Matthew F. Pusey, Jonathan Barrett & Terry Rudolph – May 2012
    Abstract: Quantum states are the key mathematical objects in quantum theory. It is therefore surprising that physicists have been unable to agree on what a quantum state truly represents. One possibility is that a pure quantum state corresponds directly to reality. However, there is a long history of suggestions that a quantum state (even a pure state) represents only knowledge or information about some aspect of reality. Here we show that any model in which a quantum state represents mere information about an underlying physical state of the system, and in which systems that are prepared independently have independent physical states, must make predictions that contradict those of quantum theory. (i.e. Any model that holds the Quantum wave state as merely a abstract representation of reality, i.e. as not a real representation of reality, must make predictions that contradict those of quantum theory.)
    - per Nature

    The following establishes the quantum wave function as ‘real’ from another angle of logic;

    Does the quantum wave function represent reality? April 2012
    Excerpt: “Similarly, our result that there is a one-to-one correspondence between the wave function and the elements of reality means that, if we know a system’s wave function then we are exactly in such a favorable situation: any information that there exists in nature and which could be relevant for predicting the behavior of a quantum mechanical system is represented one-to-one by the wave function. In this sense, the wave function is an optimal description of reality.”
    per Physorg

    Moreover wave functions are not abstract for they have been directly measured:

    Direct measurement of the quantum wavefunction – June 2011
    Excerpt: The wavefunction is the complex distribution used to completely describe a quantum system, and is central to quantum theory. But despite its fundamental role, it is typically introduced as an abstract element of the theory with no explicit definition.,,, Here we show that the wavefunction can be measured directly by the sequential measurement of two complementary variables of the system. The crux of our method is that the first measurement is performed in a gentle way through weak measurement so as not to invalidate the second. The result is that the real and imaginary components of the wavefunction appear directly on our measurement apparatus. We give an experimental example by directly measuring the transverse spatial wavefunction of a single photon, a task not previously realized by any method.
    per Nature

    As well, the following experiment actually encoded information into a photon while it was in its infinite dimensional quantum wave state, thus destroying the notion, held by many, that the wave function was not ‘physically real’ but was merely ‘abstract’. i.e. How can information possibly be encoded into something that is not physically real but merely abstract?

    Ultra-Dense Optical Storage – on One Photon
    Excerpt: Researchers at the University of Rochester have made an optics breakthrough that allows them to encode an entire image’s worth of data into a photon, slow the image down for storage, and then retrieve the image intact.,,, As a wave, it passed through all parts of the stencil at once,,,
    http://www.physorg.com/news88439430.html

    Information in a Photon – Robert W. Boyd – 2010
    Excerpt: By its conventional definition, a photon is one unit of excitation of a mode of the electromagnetic field. The modes of the electromagnetic field constitute a countably infinite set of basis functions, and in this sense the amount of information that can be impressed onto an individual photon is unlimited.
    http://www.pqeconference.com/p.....td/013.pdf

    Information In Photon – Robert W. Boyd – slides from presentation (slide 17)
    http://www.quantumphotonics.uo.....-InPho.pdf

    It is also of interest to note that slide 15 and 17 in the preceding presentation has an uncanny resemblance to Euler’s Equation (and to the DNA helix) as is plotted in the following graph:

    Graph of Euler’s Equation (page down just a bit)
    http://www.songho.ca/math/euler/euler.html

    The second problem with trying to declare the wave function abstract and trying to interpret quantum theory probabilistically is that it leads to the insanity of many worlds where there will be an quasi-infinite number of versions of you, and everyone else, in a quasi-infinite number of parallel universes,,

    You don’t exist in an infinite number of places, say scientists – January 25, 2013
    http://phys.org/news/2013-01-d.....tists.html

    Quantum probability and many worlds – 2007
    Abstract: We discuss the meaning of probabilities in the many worlds interpretation of quantum mechanics. We start by presenting very briefly the many worlds theory, how the problem of probability arises, and some unsuccessful attempts to solve it in the past. Then we criticize a recent attempt by Deutsch to derive the quantum mechanical probabilities from the non-probabilistic parts of quantum mechanics and classical decision theory. We further argue that the Born probability does not make sense even as an additional probability rule in the many worlds theory. Our conclusion is that the many worlds theory fails to account for the probabilistic statements of standard (collapse) quantum mechanics.
    http://www.sciencedirect.com/s.....980700024X

    Nonlocality and free will vs. many-worlds and determinism: The material world emerges from outside space-time – Antoine Suarez – video
    http://www.youtube.com/watch?f.....Bs#t=2469s

    I think Dr. Suarez has a very good grasp on how to properly look at the issue of probability and quantum mechanics in this following paper:

    What Does Quantum Physics Have to Do with Free Will? July 2013
    Excerpt: True quantum randomness cannot happen without nonmaterial (nonlocal) control. Even in the most simple quantum interference experiments in the lab, the random and unpredictable firing of the detectors is accompanied by an invisible coordination.
    https://www.bigquestionsonline.com/content/what-does-quantum-physics-have-do-free-will

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