Hi Stephen, >But the original issue was an assertion that the B field >lines around a straight, current-carrying wire actually form a spiral >pattern rather than circles. That seems pretty fundamental -- I don't >see how it could result from magnetic charge being present!
Yes, that's Franks ramblings, I think he's grasping at this notion of magnetic charge in an intuitive fashion. To even talk about "lines" of flux is dangerous at these macro levels. I have seen photographs of individual flux lines made by electron holography, if I remember correctly a superconductor was being imaged. The line looked like a little tornado or vortex, coming out of the substrate, thickening at the midpoint outside the substrate, then plunging back in to preserve your precious zero divergence (grin). This work was done at Mitsubishi, I can find you a nice printed ref if you're interested. So Franks spirals aren't _too_ far off the mark, given that he's just intuitively stabbing at it. >I learned this out of a relativity textbook so my view of E&M is a >little cockeyed, I'm afraid, but I don't recall anything about >violations of CoE... Its tempting to bring out the big guns, but lets start with something most of the people on this list can intuitively understand. If the amperian model is true, then it implies a continous flow of current in the ferromagnetic material. How does this happen outside of a superconductor? How does that electron keep spinning on itself to generate the field without any dissipation? >Ah -- I finally recalled the problem with magnetic charge! (Well, >anyway, the problem I'm aware of. I already said my PoV here is a bit >skewed.) -snip of interesting explaination- I don't think that would mean curtains for the physical vector potential, just the mathematical shortcuts you are taking to arrive at the field equations... Finding closed form integrals is more of a free gift of physics than a right; hence the popularity of piecewise field calculators. Thanks for the interesting response, BTW. K.
