|Date: Tue, 25 Dec 2001
Excellent question, and glad to see you thinking so deeply.
The key is in examining the well-known quantum electrodynamics model where any observable charge is clustered around by virtual charges in the vacuum of opposite sign. In other words, a "strain" in the vacuum itself is created, whereby the virtual charges of opposite sign gradually are more dense toward the observable charge.
Well, the question then is, since the observable charge will attract those virtual charges right into itself, at first blush it would seem, how is any observable charge observed at all? If equal opposite charges meet, they annihilate into photons in the pair annihilation process.
The reason is that each virtual charge is fleeting, and disappears. Let us now "think" down at incredibly fast levels, and incredibly short distances. If the virtual charges persisted, then they would continue to exist and be drawn to the observable charge, in equal amount, and the net charge would be zero. Indeed, both (the virtual "persistent") charges we are assuming temporarily, and the observable charge, would disappear in a flash by a variant of pair annihilation.
But the virtual charges DO NO persist. So the fact that some of the bare charge of the observable charge can be seen at all, is due to the fact that (at the tiny level we are speaking of), there exist continually recurring ABSENCES of the clustering virtual charges, due to them disappearing. So a function of the ratio of the time the virtual charges have vanished on the average, divided by the time the virtual charges are present on the average, is responsible for the observation of "observable charge" in the first place. You see, the "fraction of absent time" of these virtual charges is just as important as their "fraction of present time", though I've never seen such a discussion in a paper or text (such may well exist, and I just have not read it).
If it were not for that "average absent time fraction", then of course your surmise would be correct. That would then destroy the conceptual model I presented for the dipole, and one would have to go back to the drawing board.
However, it would also destroy the notion of observable charge also. So the fact that we observe an observable charge in the first place, proves that it cannot exist in the form and fashion you questioned. And it doesn't. But that is a very good question. And to be honest with you, it is only within the past year that I thought of a possible answer to that problem, which had troubled me quite a bit. I didn't phrase it that way, but phrased it as "Well, so virtual charges of opposite sign cluster any observable charge, according to QED and well established. What, then, prevents an equal charge of virtual charges being drawn to that observable charge, with a resulting pair annihilation?"
Fortunately, we can and do observe observable charge, which means that cancellation is incomplete and pair annihilation cannot occur. So that fraction of average absence time for the ever-bubbling virtual charges is there and functioning. Therefore we can indeed have an observable source charge (the amount of the bare charge that gets out during the average absence of the virtual charges), and that "not completely locally closed EM energy circulation" between the time domain and 3-space does spread out in all directions via the bubbling virtual charges of the vacuum -- only we call its characteristics in its reaction with charges (in observing its effects) by various names such as fields (more accurately, field intensities) and potentials (more accurately, potential intensities).
Another factor bearing on your question is that the observable charge is also continuously buffeted on all sides and from all directions by other virtual charges, some of the same charge and some of opposite charge, and some of completely different kinds of particles. So that "observable charge" is "jittering like crazy" down at that "very tiny level" we were thinking of . So the very simple picture of just opposite charges -- one virtual and one observable -- involved breaks down. The jitter (occurring at just about any and all frequencies) thus allows "windows" or "holes" of mismatching charge presences.
Another factor bearing on it is that the simple "virtual charge of opposite sign" does not really exist in that form either. Instead, that virtual charge -- while it is existing -- is itself surrounded and clustered by even more fleeting virtual charges of opposite sign to it. There thus is a vast "internesting" of clustering going on, with incredible intermixing of the charges and charge signs, at all sorts of levels. The bottom line is that those so-called opposite sign virtual charges must be modeled in far more complex fashion as they "close in on" the observable charge in our highly simplified "first order only" or "first approximation only" model.
The entire area actually needs a very good full bore look at it in about 11 dimensions, something beyond my own capability. All the simplified model can do is just "bound" and approximate the overall result of the actual much more complex interactions ongoing.