How does magnetic field curve geometry around and eventually loop back? Current Physics doesn't has an explanation, simply use curvature as given/intrinsic . Sorry, in science - you must defined first before use it.

Clue on terribly wrong with current understanding lied in Electron Magnetic Moment, where torque calculation in classical equation is only 1/2 of measured. Thus quickly bandaged with g-Factor (with Dirac's eation), where g=2. QED add Lamor Precession to make g =~ 2.002x. g in this case is clearly a fudge-factor to fit measured #s.

If you don't see what I wrote/talked as problems then my solutions/explanations are irrelevant as well as futile.