Re: Magnetic lines like these ?

["Rauber, Joel Phys" <RAUBERJ@mg.sdstate.edu>]

I haven't been following this thread, so the comment may be a little off 
base.
 -
> > I disagree.  Vacuum only conducts when electrons are present, but then
> > that is not a vacuum, that is an electron plasma.  A perfect vacuum is a
> > perfect conductor.  A hot filament changes the vacuum by adding an
> > electron plasma, which is itself a conductor.

I recall one of my E&M courses where our instructor calculated the 
resistivity of the vacuum; this was related to looking at wave propagation 
through the space.  It was a most pedestrian looking number (I forgot what, 
and details;) But it wasn't zero or even very small (wasn't very large 
either); i.e. not a perfect conductor.

Does anybody know what I'm remembering? or recall discussions along these 
lines?

Joel Rauber