On Tuesday, April 29, 2025 at 4:46:58 AM UTC-6 John Clark wrote:
On Mon, Apr 28, 2025 at 9:21 PM Alan Grayson <[email protected]> wrote: *> Presumably, if Maxwell's equations are solved in empty space, in the absence of charged particles, the E and B fields will be identically zero.* *Yes.* * > If the same problem is solved in Quantum EM theory, won't we also get the same classical result,* *No. If the electric, magnetic, gravitational, or any other type of field was precisely zero then you would know exactly what the energy density was in any arbitrarily short amount of time, zero. And quantum mechanics says that is impossible. So the amount of energy must be greater than zero for short amounts of time, the shorter the time the greater the energy. This is why there are virtual particles, they can't be detected directly but they produce effects that can be detected, the simplest and most dramatic is the Casimir Effect.* *> but then won't the HUP fail to be satisfied?* *I don't know about that but HUP fails to satisfy me because IHA. * Never heard of the HUP, the Heisenberg Uncertainty Principle? How can it be applied in quantum EM field theory other than on an ad-hoc basis. That is, can the HUP be derived from the princples of the theory, or is it just ad hoc? As for the Casimir Effect, it can be predicted classically, so it proves nothing about virtual particles. 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 visit https://groups.google.com/d/msgid/everything-list/ad2ef9d0-5241-4e37-a6e7-b645994bc953n%40googlegroups.com.
