On Tue, Aug 27, 2019 at 10:35 AM Jason Resch <[email protected]> wrote:
> On Mon, Aug 26, 2019 at 7:32 PM Bruce Kellett <[email protected]> > wrote: > >> On Tue, Aug 27, 2019 at 10:27 AM Jason Resch <[email protected]> >> wrote: >> >>> These videos provide a good introduction: >>> >>> https://www.youtube.com/watch?v=X5rAGfjPSWE >>> https://www.youtube.com/watch?v=fG52mXN-uWI >>> >>> Virtual particles are the basis of all particle interactions in QED, >>> called the jewel of physics for having made the most accurate predictions >>> of any physical theory. >>> >> >> The trouble is that virtual particles are internal lines in Feynman >> diagrams, and the Feynman diagrams are formed as a perturbation expansion. >> They have to be summed to make contact with physical processes. This puts >> the status of virtual particles, as ontological entities, into considerable >> doubt. Ultimately, they are nothing but a calculational device, and quantum >> amplitudes can be evaluated without ever using Feynman diagrams, so virtual >> particles need never appear anywhere. >> >> > But this "calculational device" (funny how many things are mere devices) > predicts the lamb shift as well as the Casimir effect, to great accuracy. > No, virtual particles do not predict the Lamb shift -- they are just an aid to calculating terms in the perturbation expansion of the QED vertex function. Bruce -- 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/CAFxXSLQRO54bfW2D0SOHdVRJ6FCf61Shuum9WNxPs7rJKY%2BKEQ%40mail.gmail.com.
