A particularly intriguing notion of Konstantin Meyl's is that a "complex speed of light" is derivable from the conventional interpretation of the dielectric coefficient, rendering that conventional interpretation "an offense against the basic principles of physics":
http://www.k-meyl.de/go/Primaerliteratur/2P9_0930-1-piers-extended_field_theory.pdf This seems to be his point of departure into "fringe" physics his replacement of the vector potential with his derivation of the "potential vortex".
