We report some recent experiments on motional induction, performed on partially shielded circuits. Both electro and ponderomotive forces are unsensitive to magnetic shielding. Laplace and Lorentz local forces must be applied with considerable care when dealing with motional induction.
Following our investigation on motional electromagnetic induction, we search for electromotive force (emf) generation in ?confined B-field? homopolar engines. Four independent experiments are here presented. The above experiments suggest the non local nature of motional induction.
Mikhailov claims to have measured changes in the electron's inertial mass when located inside a uniformly charged spherical shell. The above mass, calculated by Assis founded on Weber's force becomes mW = mo - qV/3c2 for a charge q placed in a region of Coulomb's potential V.
In page 161 of Mikhailov states: ?So, if q and V have same (opposite) signs there is a decrease (increase) of the particle's effective mass.? Then, for q = ?e and V = k(Q/R) > 0, we get a mass increase yielding m = mo + eV/3c2 > mo.
We remember now that also Einstein's mass-energy equivalence, mE = Energy/c2, allows us to predict the electron mass-electrostatic potential dependence, of the same order of magnitude but opposite in sign. As a matter of fact, we have described the electronic mass defect taking place in the atomic electron. Let us consider an electron inside a positively charged spherical shell of charge Q, radius R producing a potential V = k(Q/R) > 0. The mutual electrostatic potential energy is ?eV < 0, so that a positive work must be supplied to carry the electron to infinite.
With the aid of the random electrodynamics (a classical statistical theory based upon a Lorentz invariant spectral density) we revisite at a heuristic level some simple but interesting physical systems.