On Fri, Oct 23, 2020 at 4:54 PM 'Brent Meeker' via Everything List < [email protected]> wrote:
> > > On 10/23/2020 8:15 AM, Jason Resch wrote: > > > > On Tue, Oct 20, 2020 at 4:37 PM 'Brent Meeker' via Everything List < > [email protected]> wrote: > >> >> >> On 10/20/2020 1:20 PM, Jason Resch wrote: >> >> >> >> On Tue, Oct 20, 2020 at 1:23 PM 'Brent Meeker' via Everything List < >> [email protected]> wrote: >> >>> >>> >>> On 10/20/2020 5:39 AM, Bruno Marchal wrote: >>> >>> >>> On 15 Oct 2020, at 20:56, 'Brent Meeker' via Everything List < >>> [email protected]> wrote: >>> >>> You should have read Vic Stenger's "The Fallacy of Fine Tuning". Vic >>> points out how many examples of fine tuning are mis-conceived...including >>> Hoyle's prediction of an excited state of carbon. Vic also points out the >>> fallacy of just considering one parameter when the parameter space is high >>> dimensional. >>> >>> But my general criticism of fine-tuning is two-fold. First, the concept >>> is not well defined. There is no apriori probability distribution over >>> possible values. If the possible values are infinite, then any realized >>> value is improbable. >>> >>> >>> >>> I don’t think so. That is why Kolmogorov defines a measure space by >>> forbidding infinite intersection of events. In the finite case the space of >>> events is the complete boolean structure coming from the subset of the set >>> of the possible results. In the infinite domain, the measure space os >>> defined by a strict subset. I miss perhaps something, but the axiomatic of >>> Kolmogorov has been invented to solve that “infinite number of value” >>> problem. >>> >>> >>> That's a non-answer. I was just using infinite (as physicists do) to >>> mean bigger than anything we're thinking of. Kolmogorov just shaped his >>> definition to make the mathematics simpler. There's nothing in Jason's >>> analyses that defines the variables as finite. Jason just helps jimself to >>> an intuition that a value between 7.5 and 7.7 is "fine-tuned". He didn't >>> first justify the finite interval. >>> >> >> I admit as much in the article. For most parameters, we don't understand >> the range or probability distribution for the constants. >> >> >> Then how can you assert there is fine tuning. Is a value of 20*+*1 >> qualify? Does it matter whether the possible range was (0,100) or (19,21)? >> >> However, see my explanation for the cosmological constant, a value for >> which the theory can account for the expected range and probability >> distribution. >> >> >> That's right, there is a theory that tells us something about a range and >> probability distribution. But it's far from an accepted theory, and might >> well be wrong. >> > > It comes out of QFT, perhaps our most strongly tested theory in science, > at least one that offers the most accurate verified prediction in physics. > > > That "comes out of" is very misleading, since it's applying QFT to general > relativity which is not even a quantum theory. > But the quantum fields (vacuum) are known to gravitate. > The first application of QFT to the problem gave the wrong answer by 120 > orders of magnitude. > Wrong is the wrong word here. The answer was unexpectedly small by that many orders of magnitude, but it is still within the range of possibility. > I don't know what prediction you're referring to, there have been > several. Can you cite the paper? > The prediction that the vacuum state contains energy, and that this energy under QFT is the sum of each of the field energies, some of which may be positive or negative, and when they are summed, they come out to be 120 orders of magnitude smaller than the Planck energy (which is the expected energy level of each field). I don't know of a reference to the paper, but I've read it was first calculated by Feynman and Wheeler. I also found this derivation: https://i.imgur.com/m0QhWOv.png This paper <https://arxiv.org/pdf/1906.00986.pdf> gives three citations [6-8] to accompany this statement, which might also be useful to you: "Nature contains two relative mass scales: the vacuum energy density V ∼ (10−30MPl) 4 and the weak scale v 2 ∼ (10−17MPl) 2 where v is the Higgs vacuum expectation value. Their smallness with respect to the Planck scale MPl = 1.2 1019 GeV is not understood and is considered as ‘unnatural’ in relativistic quantum field theory, because it seems to require precise cancellations among much larger contributions. If these cancellations happen for no fundamental reason, they are ‘unlikely’, in the sense that summing random order one numbers gives 10^−120 with a ‘probability’ of about 10^−120." "No natural theoretical alternatives are known (for example, supergravity does not select V = 0 as a special point [1]), and anthropic selection of the cosmological constant seems possible in theories with some tens of scalars such that their potential has more than 10^120 different vacua, which get ‘populated’ forming a ‘multiverse’ through eternal inflation. String theory could realise this scenario [6–8]." [6] R. Bousso, J. Polchinski, “Quantization of four form fluxes and dynamical neutralization of the cosmological constant”, JHEP 0006 (2000) 006 [arXiv:hep-th/0004134]. [7] L. Susskind, “The Anthropic landscape of string theory” [arXiv:hep-th/0302219]. [8] S. Kachru, R. Kallosh, A.D. Linde, S.P. Trivedi, “De Sitter vacua in string theory”, Phys. Rev. D68 (2003) 046005 [arXiv:hep-th/0301240]. Jason > Brent > > It might well be wrong, but that would be more surprising to me than the > idea of an anthropic selection process operating in a multiverse. > > Jason > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/CA%2BBCJUiJ5c3kakLGC73zuRGX-6gafk0W7NGhuJJn9VOQEtzriA%40mail.gmail.com > <https://groups.google.com/d/msgid/everything-list/CA%2BBCJUiJ5c3kakLGC73zuRGX-6gafk0W7NGhuJJn9VOQEtzriA%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/a3039f54-142f-9558-984d-cfa5f65d56a0%40verizon.net > <https://groups.google.com/d/msgid/everything-list/a3039f54-142f-9558-984d-cfa5f65d56a0%40verizon.net?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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