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 everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/9acce816-33df-468c-8a98-09fa79c2726b%40googlegroups.com.
