On Wednesday, January 9, 2019 at 8:49:41 PM UTC-6, Bruce wrote: > > On Thu, Jan 10, 2019 at 1:36 PM John Clark <[email protected] > <javascript:>> wrote: > >> On Wed, Jan 9, 2019 at 7:49 PM Bruce Kellett <[email protected] >> <javascript:>> wrote: >> >> >>The following 2012 article in Physical Review letters describes a QED >>>> calculation involving 12,672 tenth order Feynman diagrams used to >>>> calculate both the magnetic moment of the electron and the inverse of the >>>> Fine Structure Constant and obtaining a value of 137.035999173 which >>>> is almost exactly the same as the experimentally derived value: >>>> >>> >>> >That is an experimentally derived value!!!!! >>> >> >> No, the experimentally derived value is 137.035999139 >> >> *>Your original claim was that the fine structure constant was >>> computable. * >> >> >> I said that was my intuition, I don't have a proof. >> >> > *it is a physical constant that must be measured.* >> >> >> I know, that's why I said the Fine Structure Constant was defined >> physically not mathematically, and that's why any physical theory that is >> in conflict with that measured value for the FSC can not be a good theory. >> Feynman's QED is not in conflict with it, in fact it produced the closest >> agreement between experiment and theory in the entire history of science. >> >> > *But it is not computable from first principles,* >> >> >> That depends on what the first principle is, if its charged particles >> behave the way Feynman said they do then you can compute a value for the >> FSC that is very very close to the best measured one. Maybe when >> measurement becomes more precise a statistically significant discrepancy >> will show up between the experimental value and the theoretical value, >> > > There is no theoretical value". All the values that we have are measured > -- often in different ways, or from the results of different experiments to > measure the same things, such as g-2, so there can be a range of measured > results. The CODATA value is their best-fit value to the whole range of > different experimental measurements. But in the final analysis, the fine > structure constant is an arbitrary physical constant that must be measured > -- there is no "theoretical value". > > Bruce >
Yes and no. The speed of light and Planck's constant for instance are measured input. The charge is both measured and estimated with charge renormalization. LC > > if so we'll have to fine something better than Feynman Diagrams because in >> science when experiment and theory fight experiment always wins. >> >> >>> *>You have to define what you mean by "computable". * >> >> >> The Fine Structure Constant is computable if and only if there exists a >> finite algorithm that can work on a finite amount of data and produce a >> number in a finite amount of time that is arbitrarily close to it. I don't >> claim to have such a algorithm I'm just saying my hunch is it exists and >> Feynman gives us reason for optimism. But I could be wrong. >> > -- 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 post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
