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Another big numbers coincidence?

  1. Jul 17, 2006 #1
    Have you ever thought why the ratio between the vacuum energy and dark energy, the total entropy of the observable universe and the squared ratio between the universe age and planck time are all of them ca. 10^121, perhaps the biggest natural number with a physical significance?

    Any comments will be welcome.

    Juan
     
  2. jcsd
  3. Jul 17, 2006 #2

    Garth

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    This isn't a coincidence, actually, unless you bring in another large number OOM 10121, perhaps the Dirac LNH number of (1040)3?

    It is the largest mismatch between theory (QT) and observation (DE) in physics and may indicate something is wrong!

    One published alternative theory that does not suffer this problem is A New Self Creation Cosmology
    Garth
     
  4. Jul 17, 2006 #3

    SpaceTiger

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    I thought we had agreed it did still suffer this problem:

    Self Creation Cosmology

    Your theory makes a small cosmological constant more "natural" (removing the cosmic coincidence problem), but does not resolve the discrepancy between particle physics and gravitational theory that leads to the huge number discussed above (the Lambda problem).
     
  5. Jul 17, 2006 #4

    Garth

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    Thank you for your comment ST.

    Actually, we agreed that SCC does have DE, but as I maintain it is not unknown DE, rather that observed in the laboratory as the Casimir force.

    This prediction of the theory can be tested (and falsified) by an experiment to look for a rounding off of the maximum Casimir force in low gravitational fields, away from the Sun and major planets, in the outer solar system.

    The problem with GR is that it makes no prediction of false vacuum density. The degree of freedom provided by the cosmological constant allows vacuum to have an energy density but it makes no prediction of what that might be. The only indication that it might be non zero is the requirement of the standard [itex]\Lambda[/itex]CDM model to have ~ 73% (by density) DE.

    The problem with QT is that the virtual energy density spectrum is cut off only by the Planck scale, hence the false vacuum provides a potentially very large and dense QFE source.

    Unfortunately for the theory, (but fortunately for us!), the gravitational curvature associated with this quantum vacuum density is only observed, if at all, as the cosmological DE at 10-121 less than that theory predicts.

    On the other hand in SCC there is a natural and moderate cut-off provided by its two field equations, i.e. the gravitational and scalar field, which require a small false vacuum density for mutual consistency.

    In flat space-time the two solutions are consistent, but the introduction of increasing curvature gradually separates the two solutions and requires a small false vacuum density. This would be made up of contributions of zero-point energy from every quantum matter field which has a natural re-normalised ‘cut-off’ Emax determined, and therefore limited, by those solutions.

    The 'Casimir' electro-magnetic vacuum field energy is predicted by SCC to have a density in the near Earth gravitational field of:
    [itex]\rho[/itex]qv ~ -2.4 x 10-9 gm.cm-3.

    Garth
     
    Last edited: Jul 17, 2006
  6. Jul 17, 2006 #5

    SpaceTiger

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    Again, that is not the Lambda problem, it is the cosmic coincidence problem. As I said, your theory could (in principle) provide a solution to this.


    You've already agreed that your theory is not a QFT, so I don't see how you can claim you have a solution to the problem. All you're doing is saying that your gravitational theory demands a certain false vacuum energy density. You've said nothing of how QFTs are to achieve a false vacuum consistent with what you predict ([itex]\Omega_{fv}=0.11[/itex]). Simply saying that they should cut off their QFTs at a certain energy scale is not a solution. For one thing, there's no motivation for the cutoff in particle physics. For another, the cutoff would have to be above the QCD scale, which makes no sense!
     
  7. Jul 17, 2006 #6
  8. Jul 17, 2006 #7

    Garth

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    Agreed, SCC is not a QFT.

    Garth
     
  9. Feb 1, 2007 #8
    New Large Number Coincidence: 10^121

    Hi, all. It turns out that there is indeed a new large number coincidence
    problem concerning pure numbers of order 10^121. However, it has
    been solved:
    http://arxiv.org/abs/physics/0611115

    Regards,
    Scott
     
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