On Tuesday, August 27, 2019 at 3:17:41 AM UTC-6, Bruce wrote: > > On Tue, Aug 27, 2019 at 7:05 PM Alan Grayson <[email protected] > <javascript:>> wrote: > >> On Tuesday, August 27, 2019 at 2:47:39 AM UTC-6, Alan Grayson wrote: >>> >>> On Tuesday, August 27, 2019 at 1:59:40 AM UTC-6, Bruce wrote: >>>> >>>> On Tue, Aug 27, 2019 at 5:39 PM Alan Grayson <[email protected]> >>>> wrote: >>>> >>>>> On Tuesday, August 27, 2019 at 1:08:33 AM UTC-6, Bruce wrote: >>>>>> >>>>>> On Tue, Aug 27, 2019 at 4:57 PM Alan Grayson <[email protected]> >>>>>> wrote: >>>>>> >>>>>>> >>>>>>> But if virtual particles don't exist, if they're based on conceptual >>>>>>> errors, what's the basis for claiming the vacuum is not a vacuum of >>>>>>> nothingness? AG >>>>>>> >>>>>> >>>>>> Virtual particles are a useful heuristic for evaluating a >>>>>> perturbation series. The conceptual error is to reify the terms in this >>>>>> series, particularly the virtual particles. Quantum foam, or the picture >>>>>> of >>>>>> virtual particles fluctuating in and out of existence, everywhere, and >>>>>> all >>>>>> the time. Is a major conceptual confusion. There are no such things as >>>>>> quantum fluctuations in the requisite sense. Disconnected Feynman >>>>>> diagrams >>>>>> do not contribute to physical processes -- this is an elementary >>>>>> text-book >>>>>> result. >>>>>> >>>>>> Bruce >>>>>> >>>>> >>>>> How then do you interpret the Casimir Effect? Isn't it used to >>>>> experimentally establish the existence of virtual particles? AG >>>>> >>>> >>>> The Casimir effect is perfectly well explained in terms of Van der >>>> Waals type forces. Explanations in terms of virtual particles don't really >>>> work because virtual particles do not exert any force on anything -- >>>> because they are not real!!!! >>>> >>>> Bruce >>>> >>> >>> I see. What about the vacuum energy? What does it consist of if not >>> virtual particles? AG >>> >> >> Part of what I'm getting at is this; if the vacuum energy has anything to >> do with the quantized EM field, the values 1/2*hbar *omega aren't photons! >> So what is the form of energy in the vacuum? AG >> > > Good question. Best answer to date is that it is Einstein's cosmological > constant. Virtual particles can play no role because disconnected particle > loops are necessarily of zero energy. > > Bruce >
Is there any experimental evidence that the vacuum energy is non zero? (I assume dark energy is inferred from the accelerating expansion, but is not considered part of the vacuum energy.) AG -- 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/46521cdd-894e-4121-bab3-dbfea634d926%40googlegroups.com.
