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A Max number of extra dimensions

  1. Nov 26, 2017 #21


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    In the case of string theory we have a double strike: extra dimensions which can give extra gauge fields a la kaluza klein, and extra gauge fields in the RR-sector.
  2. Nov 29, 2017 #22
    Our brain is part of our existence, our world, our reality.
    If the "map of reality" encoded in our brain, is just a holographic
    connection to actual reality and any argument about the sense of
    reality implying dimensionality of our physical word seems fallacious
    -as you say-the same reasoning will be applied to any assertion with
    reference to our brain.
  3. Nov 29, 2017 #23


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    Yes, the argument in principle works both ways, but my point was this:

    The "at best" holographic picture of the environment, an observer has, is a rational view originating from inference based upon incomplete and uncertain information. And the map of reality is constantly evolving.

    It is not a fallacy to act as if our world is roughly 3D, it is in fact rational. The fallacy of the theoretical physicists is to mistake the probable opinion for an absolute observer independent and timeless truth, that we see as a logical constraint. It "looks like 3D", just like our brain "looks like" a bunch of neurons communicating via electricity. But done right, these "soft" statements will converge, to effective reality. But to understand the effective reality, IMO at least i think a key is to understand the inference made. Inductive or abductive inference is not deductions. Its more like a guided random walk, all we need to make sure is that the random walker is converging and not gets lost.

  4. Nov 29, 2017 #24
    From a 3D being in a 4D spacetime forced to exist in a 2D plane of mobility, it is irrational that we don't see scale as another dimension unto itself. The vastness of space and the vastness of microscopic complexity are both just out of reach of consciousness but almost everyone believes they are there, with barely a care to their relevance...
  5. Nov 30, 2017 #25


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    Not sure what you mean here as you talk about consciousness? My reference to the brain, was not the main point. The main point in my first post was the dimensionality of state space vs computational complexity.

    Also 3D space of course just relates to the apparent dimensionality of relations between remote objects. If we talk about internal spaces and theory spaces its a different case, but less "intuitive" of course.

    About scales, I think in terms of several scales, the UV scale, IR scale and the observer complexity scale. In current theories however, the complexity scale of the observer is effectively infinite, as its typically seen as an "information sink" or classical background that are never "saturated" with information. This is why current frameworks are unable to cope with "observer complexity scaling".

    The scaling done in RG flow, is rather seen as a kind of scaling of the observational RESOLUTION, but still with a fixed (infinite) CONFIDENCE. Ie the observer still sits in a classical boundary embracing the "system" under observation. This is the situation in HEP.

    A generalisation of this would be need a generalized framework for measurement theory that can handle "inside observers" and it would also imply an interesting generalisation of renormalisation. Then renormalization should not be seen as something of releveance to curing technical problems in perturbation theory, but a way to understand how theories evolve as you tweak its parameters.

    What if if flip the coin here and consider a small observer embraced by a vastly larger system under observation? Then what we get is a cosmological theory, but formulated from the inside. This is the missing part in current formalism. And it is also why its fallacy to APPLY the framework from HEP to cosmology. It is a conceptually fallacy. Howver the mathematics of HEP has seduced us.

    Lee Smolin calles this the cosmological fallacy.

  6. Dec 1, 2017 #26
    For bosonic strings and quantum consistency the dimensions need 26 but how come in M-theory the dimensions are 11 only and not the full 26? It's like your wife has 3 million in the bank under her name while for joint account you and her have 1 million.. and you declare your family money as 1 million only.. when it should be more than that..
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