On Sunday, April 19, 2020 at 7:23:00 PM UTC-6, Lawrence Crowell wrote: > > On Sunday, April 19, 2020 at 4:50:52 PM UTC-5, Alan Grayson wrote: >> >> >> >> On Sunday, April 19, 2020 at 2:37:28 PM UTC-6, Lawrence Crowell wrote: >>> >>> Sure the Casimir effect involves QED. The virtual photons are in a sense >>> a set of gauge redundancies that can be removed, though one need the moduli >>> from these redundancies. This still defines a form of quantum topological >>> number. >>> >>> LC >>> >> >> You refer to QED, but aren't wan der Waal forces non quantum? AG >> > > Van der Waal force is just a dipole-dipole interaction, such as what > happens with water on the fluid surface. This can well enough be quantized. > > LC >
But if you can explain Van der Waal forces without QED, why would you invoke it? I mean, if it's not necessary, and there's no need to invoke it, doesn't that put the EM vacuum energy on a dubious basis? AG > > >> >>> On Sunday, April 19, 2020 at 11:30:51 AM UTC-5, Alan Grayson wrote: >>>> >>>> >>>> >>>> On Sunday, April 19, 2020 at 9:11:46 AM UTC-6, Lawrence Crowell wrote: >>>>> >>>>> The only thing that is measured is a difference in energy, and the >>>>> modes between two parallel plates are different from those outside. So >>>>> the >>>>> difference in energy results in this slight pressure. >>>>> >>>>> LC >>>>> >>>> >>>> From Wiki, below. Apparently there's an interpretation of the Casimir >>>> effect which doesn't depend on vacuum energy, which, as I recall, is >>>> Bruce's position on this issue. If no vacuum energy, then the claim that >>>> photons and other elementary particles arose from the vacuum in the very >>>> early universe is on dubious grounds. AG >>>> >>>> Relativistic van der Waals force[edit >>>> <https://en.wikipedia.org/w/index.php?title=Casimir_effect&action=edit§ion=5> >>>> ] >>>> >>>> Alternatively, a 2005 paper by Robert Jaffe >>>> <https://en.wikipedia.org/wiki/Robert_Jaffe> of MIT states that >>>> "Casimir effects can be formulated and Casimir forces can be computed >>>> without reference to zero-point energies. They are relativistic, quantum >>>> forces between charges and currents. The Casimir force (per unit area) >>>> between parallel plates vanishes as alpha, the fine structure constant, >>>> goes to zero, and the standard result, which appears to be independent of >>>> alpha, corresponds to the alpha approaching infinity limit," and that "The >>>> Casimir force is simply the (relativistic, retarded >>>> <https://en.wikipedia.org/wiki/Retarded_potential>) van der Waals >>>> force between the metal plates."[17] >>>> <https://en.wikipedia.org/wiki/Casimir_effect#cite_note-17> Casimir >>>> and Polder's original paper used this method to derive the Casimir-Polder >>>> force. In 1978, Schwinger, DeRadd, and Milton published a similar >>>> derivation for the Casimir Effect between two parallel plates.[18] >>>> <https://en.wikipedia.org/wiki/Casimir_effect#cite_note-18> In fact, >>>> the description in terms of van der Waals forces is the only correct >>>> description from the fundamental microscopic perspective,[19] >>>> <https://en.wikipedia.org/wiki/Casimir_effect#cite_note-19>[20] >>>> <https://en.wikipedia.org/wiki/Casimir_effect#cite_note-20> while >>>> other descriptions of Casimir force are merely effective macroscopic >>>> descriptions. >>>> >>>>> >>>>> On Saturday, April 18, 2020 at 10:40:45 PM UTC-5, Alan Grayson wrote: >>>>>> >>>>>> Does the Casimir effect establish that the vacuum has intrinsic >>>>>> energy, and if so, what is its form? TIA, 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/9acce816-33df-468c-8a98-09fa79c2726b%40googlegroups.com.
