On Thu, Jan 10, 2019 at 1:36 PM John Clark <[email protected]> wrote:
> On Wed, Jan 9, 2019 at 7:49 PM Bruce Kellett <[email protected]> > 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 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.
