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Testability thread is great (keeping comment/discussion out works, too)

  1. Jun 17, 2005 #1

    marcus

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    "Testability" thread is great (keeping comment/discussion out works, too)

    I just noticed this neat thread Wolram started where if you have a cosmology model you can list its predictions, to be archived away to consult later and see if they agree with observation.

    quite understandably Wolram says please do not comment or discuss, simply list your predictions
    (if you have developed an alternative model to the standard one)
    that keeps the thread clear. it seems to work probably because PF people respected the idea

    I am commenting here (so as not to clog the original thread) that I really like some of the predictions.
     
  2. jcsd
  3. Jun 17, 2005 #2

    wolram

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    Thankyou very much Marcus.
     
  4. Jun 17, 2005 #3

    ohwilleke

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    I think wolram's thread would be a good place for a variety of predictions. For example, I seem to be aware of someone who has some predictions about the relationship between fundamental constants and black hole frequency.
     
  5. Jun 17, 2005 #4

    marcus

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    Smolin's CNS conjecture! cosmological natural selection. thanks so much for reminding us of that, ohwilleke. But that is definitely Smolin's idea, I could not post predictions from it in Wolram's thread because I don't have rights to any piece of it.

    CNS conjecture is that the dimensionless (purely numerical) fundamental physical constants of nature are what they are because those values favor a universe reproducing itself thru its black holes

    so the CNS prediction is that nobody is ever going to find that a few percent change in one of the constants would result in the universe breeding more prolifically----forming galaxies and stars more readily, having a greater percentage of those stars turn into black holes instead of cold cinders etc.

    CNS prediction challenges you to find a constant which if you tweak it would tune the universe to be better at producing lots of hole. it says that the constants we got are already ideally tuned to do this---or if not global optimal at least local optimal: better than any nearby alternatives.

    it is a bizarre conjecture, but it might just survive testing.

    I think that this conjecture will not really come into its own until there is a satisfactory quantum spacetime dynamics (quantum gravity) and until the standard particle model is rebuilt on the basis of that new quantum continuum----at that point one will be facing a different set of fundamental physical constants, hopefully fewer, and those constants will have to do with both spacetime geometry and matter, and people will be asking "why are these numbers what they are?"----then maybe they will consider CNS.

    but right now the numbers are split into two lists----the standard particle model numbers and the standard cosmology model numbers---and no one is completely confident that they are the right numbers to be trying to explain, they just kind of provisionally work in their respective models
     
  6. Jun 18, 2005 #5

    wolram

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    Hi Ohwilleke, Predictions that are not in the "standard model" are welcome
    but i would appreciate it if only "testable", predictions are posted.
     
    Last edited: Jun 18, 2005
  7. Jun 18, 2005 #6

    wolram

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    By Marcus
    Smolin's CNS conjecture! cosmological natural selection. thanks so much for reminding us of that, ohwilleke. But that is definitely Smolin's idea, I could not post predictions from it in Wolram's thread because I don't have rights to any piece of it.
    Marcus, as long as it is not in the SM and is kept to a prediction, you are
    welcome. The emphasis is on testabilty with known technology.
     
    Last edited: Jun 18, 2005
  8. Jun 19, 2005 #7
    With all the respect, I don't understand the craze about the CNS conjecture. Have you been brainwashed by jeff about LQG being a dead end? :mad: I still stick to LQG, CNS is an ill-defined theory, there's no explanation about the mechanism that makes the Universe to emerge from a black hole. The framework of LQG is more robust, at least there are formulae for the contraction and posterior expansion of the Universe. Don't forget that CNS is not part of LQG


    CNS conjecture, also known as Fecund Universes theory, was somehow alterated by Louis Crane to produce a new conjecture called the Meduso-anthropic principle
    The paper is this, and the abstract indicates that this is a modification done before Smolin's work was published. In the Meduso-anthropic principle, succesful industrial civilizations are able to create new black holes, and new Universes spring from these black holes
    http://xxx.lanl.gov/abs/hep-th/9402104
     
    Last edited: Jun 19, 2005
  9. Jun 19, 2005 #8

    Garth

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    And were they having a joke when they created this one?

    Garth
     
  10. Jun 19, 2005 #9

    wolram

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    Im still waiting for some notable replies, shyness is not an option, print it
    or miss the boat, i dont want this thread to run to long, for obvious reasons.
    Good Heart to you all.
     
  11. Jun 19, 2005 #10

    marcus

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    Meteor that is quite a remarkable essay of Louis Crane, thanks for giving us the link
    http://xxx.lanl.gov/abs/hep-th/9402104

    As for the early history of the CNS idea (not Crane's variant) it goes back at least this far, as i think you know, maybe dont have to say:
    Smolin, L.: Did the universe evolve? Class. and Quantum Grav. 9 (1992) 173-191.

    regarding the simple business of priority (not that it matters to us much in this case) Louis Crane article was 1994 and it did indeed refer to some unidentified work of Smolin which had not yet been published. Of course Smolin had already published his CNS thoughts in 1992.
    It could be other people thought of this before Smolin but i dont know of any.

    In repose to other parts of your post, meteor, I agree with a lot of what you say. I think LQG is a promising and productive research effort---also it changes as it grows. New people are getting into LQG and spin foams research and some new people are becoming prominent (like Laurent Freidel) in their own right.

    I also agree that CNS is not part of LQG or dependent on it.

    I also agree that CNS is still poorly defined. A lot more could be done about deriving hard predictions from it.

    however i think CNS is an interesting conjecture, meteor. very worth checking once some more predictions have been derived from it.
     
    Last edited: Jun 19, 2005
  12. Jun 19, 2005 #11

    Nereid

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    It would be fascinating to see some in the various non-mainstream camps take the bull by the horns and put their ideas on the line, as numbers ... but I think the chances of anyone doing so are slim to none (apart from Garth; then again, he'd already said SCC will stand or fall within ~18 months of GPB, so he's pretty much an exception).

    For the LQG folk, there are a number of things which may count as evidence in their favour, but nothing concrete (and the ESSENCE project, and others, are already looking) ... is LQG 'non-mainstream'?
     
  13. Jun 20, 2005 #12

    wolram

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    By Neried

    is LQG 'non-mainstream'?

    I suggest it is, Even though i have great respect for the top people in
    this field, Quantum gravity is far from factual, but has some predictions
    that would be welcome.
    If anyone has facts, figures, test predictions for any alternate theory
    please feel free to post them.
     
  14. Jun 20, 2005 #13

    ohwilleke

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    Scientists see over the horizon only because they stand on the shoulders of giants.
     
  15. Jun 20, 2005 #14

    wolram

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    Originally Posted by marcus
    But that is definitely Smolin's idea, I could not post predictions from it in Wolram's thread because I don't have rights to any piece of it.

    Marcus, if it is a prediction, then you have, "every right", "as long as it is testable", ye gods do i have to extract blood from a stone :smile:
    but i guess Neddie predicted the out come of this thread.
     
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