Description:The part "Fundamentals" is novel, first in that it stresses the use of electric currents in Magneto-Fluid-Dynamics. As a rule, authors discuss magnetic field lines without ever referring to the required electric currents. Second, the book stresses the importance of electric space charges inside conductors that move in magnetic fields. It is the custom to disregard both the required electric currents and the field of the space charges. The "Case Studies" concern solar phenomena and the EarthВґs magnetic field, stressing electric currents and electric space charges. Each case study is based on a published, or soon to be published, paper.