Today’s standard textbooks treat the theoretical structure of electric and magnetic fields, but their emphasis is on electromagnetic radiation and static-electric and magnetic fields. In this book, Eugene Parker provides advanced graduate students and researchers with a much-needed complement to existing texts, one that discusses the dynamic electromagnetism of the cosmos–that is, the vast magnetic fields that are carried bodily in the swirling ionized gases of stars and galaxies and throughout intergalactic space. Parker is arguably the world’s leading authority on solar wind and the effects of magnetic fields in the heliosphere, and his originality of thought and distinctive approach to physics are very much in evidence here. Seeking to enrich discussions in standard texts and correct misconceptions about the dynamics of these large-scale fields, Parker engages readers in a series of conversations that are at times anecdotal and even entertaining without ever sacrificing theoretical rigor. The dynamics he describes represents the Maxwell stresses of the magnetic field working against the pressure and inertia of the bulk motion of ionized gases, characterized in terms of the magnetic field and gas velocity. Parker shows how this dynamic interaction cannot be fully expressed in terms of the electric current and electric field. Conversations on Electric and Magnetic Fields in the Cosmos goes back to basics to explain why classical hydrodynamics and magnetohydrodynamics are inescapable, even in the deepest reaches of space.