This book provides an understanding of the physics at work in sunspots and solar coronal loops, and offers a new approach to Magneto-Fluid-Dynamics (or Magneto-Hydro-Dynamics).The book stresses the use of electric currents in Magneto-Fluid-Dynamics. As a rule, authors discuss magnetic field lines without referring to the required electric currents. It also stresses the importance of electric space charges inside conductors that move in magnetic fields.

Paul Lorrain is the main author of three books: Electromagnetic Fields and Waves, third edition 1988, Electromagnetism, Principles and Applications, second edition, 1990, and Fundamentals of Electromagnetic Phenomena, first edition 2000, all published by Freeman, New York.  He is also the main author of 22 papers published in the last 22 years in major physics, astrophysics, and plasma physics journals.  He has worked in universities and research institutes in several countries.  He is presently Visiting Professor in the Department of Earth and Planetary Sciences at McGill University in Montréal, Canada.

François Lorrain is a co-author of the first and third of the above three books. He has also published a book, Réseaux sociaux et classifications sociales ; essai sur l'algèbre et la géométrie des structures sociales, Hermann, Paris, 1975. In relation to Magneto-Fluid-Dynamics, he has recently published an article entitled 'Estimating the order of magnitude of derivatives in physics by means of characteristic lengths and times' in the American Journal of Physics, 72 (5), May 2004, pp. 683-690. Presently he teaches in the Département de mathématiques et d'informatique, Collège Jean-de-Brébeuf, Montréal (QC), Canada.