On Saturday, January 12, 2019 at 4:17:56 PM UTC-6, Brent wrote: > > > > On 1/12/2019 2:51 AM, Philip Thrift wrote: > > > > On Friday, January 11, 2019 at 7:19:06 PM UTC-6, Brent wrote: >> >> >> >> On 1/11/2019 1:57 PM, Philip Thrift wrote: >> >> >> >> On Friday, January 11, 2019 at 2:46:35 PM UTC-6, Brent wrote: >>> >>> >>> >>> On 1/11/2019 6:01 AM, John Clark wrote: >>> >>> On Thu, Jan 10, 2019 at 8:18 PM Brent Meeker <[email protected]> >>> wrote: >>> >>> * > The fine structure constant is e^2/hbar*c. Those three values are >>>> measured independent of any Feynman diagrams* >>>> >>> >>> Absolutely correct. So if you use Feynman diagrams to predict what some >>> physical system is going to do, such as a physical system of 2 electrons >>> being hit by a photon of light with a wavelength small enough to contain >>> enough energy to prevent the electrons repulsion, then you'd better get a >>> number very close to the Fine Structure Constant. If you don't then Feynman >>> Diagrams aren't any good. >>> >>> They didn't use 12,672 Feynman Diagrams because they wanted to know >>> what the Fine Structure Constant was, they already knew what that >>> number was to many decimal places from exparament, they used 12,672 >>> Feynman Diagrams because they wanted to see if Feynman Diagrams worked. >>> And it turned out they worked spectacularly well in that situation, and >>> that gives scientists great confidence they can use Feynman Diagrams in >>> other situations to calculate what other physical systems will do that >>> involve the Electromagnetic Force. >>> >>> >>> There's always an interplay between theory and experiment. It's >>> completely analogous to Maxwell's discovery that light is EM waves. There >>> were already experimental values of the permittivity and permeability of >>> the vacuum and there were values for the speed of light. Maxwell showed >>> that his theory of EM predicted waves and using the permittivity and >>> permeability values the speed of the waves matched that of light. Now the >>> speed of light is a defined constant and so are the permittivity and >>> permeability of the vacuum. So the connecting of the three values by a >>> theory allows their values to be defined. In the case of the anomalous >>> magnetic moment of the electron, hbar and c are already defined constants. >>> So quantum field theory (for which Feynman diagrams are just a >>> calculational tool) linked them and e to g. >>> >>> Brent >>> >>> >> >> >> If Feynman Diagrams (tools) are sufficient (to match experimental data) >> then Quantum Field Theory can be thrown in the wastebasket. >> >> >> ?? Feynman Diagrams are just a mathematical trick for summing up terms to >> approximate the propagator of QFT. >> >> Brent >> > > > You just make Feynman Diagrams the fundamental elements of the theory, and > propagators derived from them. > > > How many diagrams? The propagator has a clear interpretation as > connecting the field at x with the field at y. Feynman showed that his > diagrams provided a good mnemonic for the infinite number of terms that > would sum to the propagator. If you take the diagrams as fundamental you > then need to specify how many. > > > Just like histories are made fundamental, and Hilbert Spaces are derived > from them. > > > Hilbert spaces are infinite dimensional vector spaces. So you have the > same problem: How many histories? > > Brent > > > https://arxiv.org/abs/1002.0589 > > Theories do not come from Mount Olympus. > > - pt > > As many histories/diagrams as you need. There are supercomputers now.
But what do physicists *really *think is *closer to actual reality*? Something closer to Histories/Diagrams or to a Hilbert Space. Do some really think that* in fact* *material reality is actually an infinite-dimensional Hilbert Space?* That is so freaking bizarre, isn't it, when you think about it. - pt -- 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.
