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I The Holographic Principle

  1. May 30, 2017 #26

    Buzz Bloom

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    Hi craigi:

    Since I will never be a well educated physicist, I am quite curious to understand, as best I can, how a well educated physicist thinks intuitively about physics. In the quote you use "our" (which I underlined in the quote to facilitate locating the word). Does "our" include well educated physicists?

    I get the impression from various discussions on this site (as well as from the well known Richard Feynman quote: No one understand quantum mechanics) that when someone becomes a well educated physicist, his/her intuition about the "construction of the world" remains flawed and inadequate, unless the intuition has become entirely mathematical. This is because that for many branches of physics (including quantum mechanics) the way the world works seems to be only accurately described (without metaphorical approximations) in terms of the math.

    In this context, I am guessing that the intuition regarding the construction of the world of those well educated physicists who are excluded from "our" now have intuitions which have become completely mathematical. On the other had, the intuition of those well educated physicists who remain included in "our" are those whose intuitive construction of the world remain inadequate.

    I would be most interested to see your comments about this.

    Regards,
    Buzz
     
    Last edited: May 30, 2017
  2. May 30, 2017 #27
    Yup. Our human intuition doesn't work very well for anything other than Classical Mechanics and even there it is limited. It's not possible (as far as I'm aware) to train intuition.

    I shouldn't speak for anyone else. There are many people who understand Physics much better than me and spend more time immersed in various fields of specialisation, but when I use the word intuition I use it to mean an instinctive human understanding.
     
  3. May 30, 2017 #28

    phinds

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    I certainly agree w/ all of that but I do think that people who have been immersed in any technical field for a long time do develop an understanding that could perhaps be called "intuition". That may just be semantics though.
     
  4. May 31, 2017 #29
    Can I refer back to what Craigi said that the idea that there is a reality in 2D at the edge of the cosmos is a popularisation of what the Holographic Principle is really all about. Is it an inaccurate simplification of ideas which are beyond most folk's mathematical training ?

    I watched a few things by Susskind and his colleagues on this, and to me they seemed to be pretty much saying that (theoretically) this really is a 3D projection from a 2D reality. How far should it be taken as truth or analogy.

    Also, in holography there is a light source, it only works with a laser beam. Is there an equivalent light source in the holographic principle ?

    If the analogy was a really close one then shouldn't there be a source of energy beyond the edge of the cosmos which animates the hologram ? How far should we take the analogy with a mundane hologram ? Ta.
     
  5. May 31, 2017 #30
    Thanks for taking the time to watch that. I got his book Visual Intelligence which is a cool read. I won't side track into the ins and outs of cognitive science, but the Hol Pri did sound like it was saying analogous things to human perception as we understand it, and I didn't see that discussed anywhere. I know Hoffman does maintain a discussion of the Hol Pri with regards to his own theories on one of his papers or youtube vids, and name checks Susskind.
     
  6. May 31, 2017 #31
    The problem with this is that without knowing what it is that is encoded on the boundary it doesn't tell you much. We can encode in any number of dimensions we choose. For example, the computer you're using right now, uses a 1 dimensional memory system, from that you're looking at a 2D image. We can create 3D representations with it and so on.

    If you want to make genuine progress in understanding the Holographic Principle, the question you need to be asking is what it is which is encoded on the boundary.

    I also want to re-iterate that it makes little sense to talk of the lower dimensional representation as more real than your familiar instinctive human representation of the world.


    No. There is no analogue of the light source in the Holographic Principle. The term Holographic simply refers to a higher dimensional representation stored on a lower dimensional surface.

    This has no meaning in the Holographic Principle.
     
  7. May 31, 2017 #32

    phinds

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    ??? How do you arrive at that conclusion? Do you understand the addressing schemes used in computers?
     
  8. May 31, 2017 #33
    Yup.
     
  9. May 31, 2017 #34

    phinds

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    Yup, what ?? I asked how you arrived at the conclusion.
     
  10. May 31, 2017 #35
    It is typical in a computer system for each memory address to be assigned a unique integer from a set of contiguous numbers, in essence a one dimensional array.

    I'm not sure where you're going with this, but I don't really want to go into memory banks, video memory, virtual addressing, memory mapping, indirect jump vectors, multi-dimensional arrays, etc. because I don't think it's helpful to the discussion at hand.
     
  11. May 31, 2017 #36

    phinds

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    I simply meant that the memory is NOT 1D as you stated. It is 2D and I wondered how you concluded that it is 1D. when you say it is a 1D array, what you are completely ignoring is that it is a 1D array of strings of binary digits, which means it is actually a 2D array.
     
  12. May 31, 2017 #37
    In this sense, I would say that it can be seen as either 1D, as I described, 2D as you describe, or even higher dimensional when we take into account memory banking etc. Which can be a useful example of the point I was making. We can represent information in any number of dimensions which we choose and the key to understanding the Holographic Principle is to understand what it is that is encoded on the lower dimensional surface.
     
  13. May 31, 2017 #38
    Re: computer thing. Computers are objects, their memory hardware is built in 3D. You may be able to argue that the electrons used in the memory are point particles. Maybe it is too much of an abstraction to say that memory and monitors work in less than 3D. Or maybe you mean that the binary 0 or 1 is a dimension, but not a physical one - dimension in a broader sense ?
    But taking that to holographic principle, how would information be held in 2D on the surface of a volume ? That is, would it be in some abstract informational form that is perfectly and truly 2D ? Or would it be in matter, which is really 3D ?
    For example in Susskind's black hole, anything that fell into the black hole can be represented in the configuration of energy or matter on it's event horizon ?
    I got to admit that I get confused about what people mean by 1D and 2D in the real world, given that these are mathematical abstractions applied to things which have 3 dimensions.
    What does the information theory say, can information really have 2 dimensions ? Maybe that's another discussion for another thread.
     
  14. Jun 1, 2017 #39
    Not quite. The bit is a unit of information. A bit is stored in a physical form in the familiar 3 spatial dimensions. Within computer hardware and software, each group of 8 bits, a byte, is referenced in an abstract 1 dimensional form. Any section of that same memory can also be referenced in 2 dimensions, or in any number of dimensions which the programmer chooses.

    Yes. The information is encoded in an abstract mathematical form.

    The only way we can access information in the physical world is through a collection of particle interactions which take place in the familiar 3 spatial dimensions.

    When we talk of 2D it might be a mathematical abstraction or it might be a 2D projection within the familiar 3 spatial dimensions.

    Yes. We can represent information in however many dimensions we like, but again this is a mathematical abstraction.
     
    Last edited: Jun 1, 2017
  15. Jun 1, 2017 #40
    OK thanks. We can say some things about computer memory using the holographic principle can't we ?
    Wikipedia says,

    "For a given energy in a given volume, there is an upper limit to the density of information (the Bekenstein bound) about the whereabouts of all the particles which compose matter in that volume, suggesting that matter itself cannot be subdivided infinitely many times and there must be an ultimate level of fundamental particles. As the degrees of freedom of a particle are the product of all the degrees of freedom of its sub-particles, were a particle to have infinite subdivisions into lower-level particles, the degrees of freedom of the original particle would be infinite, violating the maximal limit of entropy density. The holographic principle thus implies that the subdivisions must stop at some level, and that the fundamental particle is a bit (1 or 0) of information."​

    So our adoption of binary in the use of computers is a representation, in a way, of a more fundamental digital nature that matter has.
    What does it mean that the fundamental particle is a bit of information ? Does that mean that the matter turns out to not really be matter at it's smallest scale and smallest subdivision, but rather is something abstract - a bit ?
    What is it that is being flipped between 1 and 0, or yes and no, at that scale ?

    And information is proportional to surface area, an example given is that spheres packed within a larger sphere mean there can be more information stored in the larger sphere. So would that mean that a computer memory of a given volume can store more information if it is compartmentalized into smaller volumes within itself ?

    I just read a meditation on holographic theory and computer bits here
    https://www.scientificamerican.com/article/information-in-the-holographic-univ/

    This seems to me to be saying that any analogue conception of the universe cannot be true,

    "Fields, such as the electromagnetic field, vary continuously from point to point, and they thereby describe an infinity of degrees of freedom. Superstring theory also embraces an infinite number of degrees of freedom. Holography restricts the number of degrees of freedom that can be present inside a bounding surface to a finite number; field theory with its infinity cannot be the final story."​

    Does this mean we live in a digital universe of points that are either yes or no, that matter or energy cannot simply slide around anywhere but has to have specific locations where it either does or doesn't exist ? Or am I off on my own tangent there ?

    thanks
     
  16. Jun 1, 2017 #41
    That's a simple model where a region of space would have a finite maximum information storage capacity, but it doesn't match the physics.
     
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