On Friday, October 23, 2020 at 9:24:39 PM UTC-5 Brent wrote:
> > > On 10/23/2020 3:52 PM, Jason Resch wrote: > > > > 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. > > > "Known" how? You can write down a calculation...which give infinity as an > answer. Having arrived at an obviously wrong answer, you can introduce a > cutoff that you guess at based on some dimensional analysis and get an > answer that's wrong by 120 orders of magnitude, instead of infinitely. And > you then say this shows we know something like this must be right??? > > > > >> 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. > > > Which is exactly what's wrong with the idea of "fine-tuning". The "range > of possibility" is just pulled out of thin air. Suppose life were possible > for 1e-60 ev/m3 to 1e-20 ev/m3. Would that be "fine-tuning" because > (1-e-20 - 1e-60)<<1 or because 30 orders of magnitude is small compared to > infinity. > > > > >> 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." > > > But who says the random number are order 1. > > It's all just fantasizing. > > Brent > > > "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]. > > The Bousso-Polchinski paper is the main development with computing YM gauge fluxes through branes wrapped on Calabi-Yau compactified spaces. It has been a long time since I have read this paper to be honest. It though looks at cases of generic topologies of CY manifolds and these gauge fluxes. It is a curious reading, for a lot of this is with Gauss-law type calculations learned as an undergraduate in EM classes. The problem with all of these string and M-theoretic work is that it really works on AdS vacua, not well on dS (deSitter) vacua. The AdS has negative vacuum energy or cosmological constant, which means it can accommodate the type-0 bosonic string negative vacuum energy. In dS based superstring theory, even if one sets the theory with positive vacuum energy there is then an obstruction to STU transformations between string types, or at least to the bosonic string. This is one aspect to the Vafa swampland hypothesis, where the positive energy of the dS vacuum is a sort of breaking mechanism on string/M-theory. I have worked on looking at the problem with the quantum vacuum in black hole coalescence. The quantum hair on the black holes is in a Casimir configuration that can excite the production of particle fields and gravitons. The spacetime is AdS-like, where string/M-theoretic structure might re-emerge. My paper https://www.mdpi.com/657568 and https://arxiv.org/abs/2007.01106 then suggests that in a deformed AdS_4 spacetime or quantum vacuum, equivalently to CFT_3, the N = 2 SUSY and supergravity may hold. Signatures of this may exist in BMS symmetries or charges induced on a gravitational wave interferometric detector. How this fits into the STU structure of AdS_5 and the “broken world” of dS swampland is a region to study. The dS_4 spacetime of the observable universe may be a holographic screen on AdS_5, either the conformal boundary or a junction condition between causal wedges. It is tempting to think this is CFT_4 in the Maldacena AdS/CFT correspondence, but it is hard to know how to build a graviton from this. The Weinberg-Witten theorem puts some no-go limits on building gravitons from lower spin fields. LC > > 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. > 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%2BBCJUh3auOJ8fLVaLUFF2dsyHZSHPd%3DXjDQRwLQFuTvJjiH4A%40mail.gmail.com > > <https://groups.google.com/d/msgid/everything-list/CA%2BBCJUh3auOJ8fLVaLUFF2dsyHZSHPd%3DXjDQRwLQFuTvJjiH4A%40mail.gmail.com?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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