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Holographic projections onto the surface of a sphere

  1. Jul 24, 2011 #1
    I was reading the Scientific American latest edition and it was claimed that everything within the boundary of a particular timeframe volume can be described equally well by the projection of each event onto the surface.
    Is this accepted dogma?
    Suppose I picture (apparently I can't but anyway...) the surface as an irregularly shaped bubble are the events within the boundary projecte onto the suface as entirely 2 dimensional or , if they are pancake shaped does that make them 3 -dimensional?
    Apologies in advance for my clear ignorance of the subject and also if I have posted in the wrong forum
  2. jcsd
  3. Jul 24, 2011 #2
  4. Jul 25, 2011 #3
    I'll take a look at that
  5. Jul 26, 2011 #4
    You can get an introduction here:

    Holographic information is a favorite of Leonard Susskind...he has some interesting theories regarding information on black hole horizons...any horizons. For example, one can conjecture that if our universe is finite and bounded, the boundary contains all the information that we think of classically as contained within the inerior volume.

    Susskind has some very interesting approaches in THE BLACK HOLE WAR where he describes he decades long arguments with Stephen Hawking on information loss in black holes...
    a few of his explanations:

    Today a standard concept in black hole physics is a stretched horizon which is a layer of hot microscopic degrees of freedom about one Planck length thick and a Planck length above the event horizon. Every so often a bit gets carried out in an evaporation process. This is Hawking radiation. A free falling observer sees empty space.

    Everything inside a region of space can be described by information bits restricted to the boundary. The world is pixilated! The maximum number of bits of information that can fit in a region of space is equal to the number of Planck sized pixels that can be packed on the area boundary…a hologram. (304)

    The question of where a [particular bit of information is located does not have a unique answer. Each successively larger boundary includes all the previous information until we come to the boundary of the universe or infinity..….ordinary Quantum mechanics makes an objects location slightly uncertain; the holographic principle means every time we seek the location of information on the hologram it’s always out at the next level!!!!
  6. Jul 27, 2011 #5
    not to pretend that I have absorbed with the information in the replies to my post yet but that sounds somehow both familiar and reassuring...a bit like the Cheshire Cat.
  7. Jul 27, 2011 #6
    Those three paragraphs I posted were not precise quotes....I shortened ideas....so it's not like I have been studying such things for decades and understand all the implications....but one thing is for sure: the more we learn the less "reality" is what it appears.
  8. Jul 28, 2011 #7
    The Cheshire Cat appears and disappears when we start worrying about what an in falling observer experiences. But since an in falling observer cannot communicate what it is they observed after passing through the event horizon, it seems to me that we should spend not so much time worrying about it. Rather, IMVHO, we should consider what an in falling object looks like to a distant observer. Considering GR, an in falling object never makes it past the event horizon. Rather it's spread across the surface of the event horizon and red shifted into infinity. Thus, everything that "falls into a black hole" exists on the 2D (+t) surface, from the perspective of the distant observer.
  9. Jul 30, 2011 #8
    an example is a black hole, the overall entropy is counted by the amount of plank squares on it s surface (The surface of the event horizon) This shows that the information that tells you about the black hole is kept on the surface. What if this describes our universe, what if our universe's information is kept on a 2D surface at the edge of our universe. The information exchange that happens there describes what we do here :D
  10. Aug 10, 2011 #9
    I think I read that our own universe could be described on its outer suface if it was a black hole (unless I am misremembering -or if that was just one of the theories that allowed this).

    So how would we know if our own universe was a black hole ? Are there any experiments that could have a bearing on this?
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