Conversations on Electric and Magnetic Fields in the Cosmos

by Eugene N. Parker

Overview

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.

Product Details

ISBN-13:	9780691128412
Publisher:	Princeton University Press
Publication date:	02/18/2007
Series:	Princeton Series in Astrophysics , #12
Edition description:	New Edition
Pages:	200
Product dimensions:	6.00(w) x 9.25(h) x (d)

About the Author

Eugene N. Parker is S. Chandrasekhar Distinguished Service Professor Emeritus of Physics and Astronomy at the University of Chicago.

Table of Contents

List of Illustrations     xi
Acknowledgments     xiii
Introduction     1
General Remarks     1
Electromagnetic Field Equations     3
Electrical Neutrality     7
Electric Charge and Magnetic Field Dominance     12
Electric Fields     15
Basic Considerations     15
Definition of Charge and Field     16
Concept of Electric Field     17
Physical Reality of Electric Field     20
Electric Field Pressure     22
Magnetic Fields     25
Basic Considerations     25
Experimental Connection     26
Differential Form of Ampere's Law     27
Energy and Stress     29
Detecting a Magnetic Field     32
Field Lines     37
Basic Considerations     37
The Optical Analogy     39
Maxwell's Equations     43
Maxwell and Poynting     48
Poynting's Momentum and Energy Theorems     48
Applications     52
Electric and Magnetic Fields in Matter     52
SI Units     55
Systems of Units     59
Chaucer Units     63
Moving Reference Frames     65
Lorentz Transformations     65
Electric Fields in the Laboratory     66
Occam's Razor and the Tree in the Forest     67
Electric Field in a Moving Plasma     68
Net Charge in a Swirling Plasma     71
Hydrodynamics     74
Basic Considerations     74
Derivation of the HD Equations     76
The Pressure Tensor     79
Pressure Variation in Uniform Dilatations     82
Shear Flow     85
Effects of Collisions     86
Off-diagonal Terms and Viscosity     89
Summary     91
Magnetohydrodynamics     92
Basic Considerations     92
Diffusion and Dissipation     96
Application of Magnetic Diffusion     98
Discussion     101
Partially Ionized Gases     102
An Electric Current to Satisfy Ampere     108
Partiele Motion Along B     114
Time-varying Magnetic Field     119
Comments     121
Singular Properties of the Maxwell Stress Tensor     123
Magnetic Equilibrium     123
Calculation of the Equilibrium Field      128
Equilibrium in Stretched Field     129
Resolving the Contradiction     132
Formation of TDs     133
Rapid Reconnection at an Incipient TD     137
Quasi-steady Dissipation at a TD     142
Comments     147
Summary     147
Electric Circuit Analogy     148
A Simple Example of an Electric Circuit     149
Popular Electric and Magnetic Fields     154
Electrostatically Driven Expansion of the Universe     157
Relaxation of Electric Charge Inhomogeneity     159
Imposition of a Large-scale Electric Field     162
Electric Charge Density in an Electric Field     165
The Transverse Invariant w[subscript n][superscript 2]/B     167
Blocking the Flow of Electric Current     169
References     173
Index     179

What People are Saying About This

Levy

Nobody has contributed more, or more deeply, to our understanding of the physics of astrophysical magnetofluids than Eugene Parker. Conversations on Electric and Magnetic Fields in the Cosmos provides those of us who have had the privilege of learning directly from him a chance to revisit the elegant insight, structure, and breezy wit that Parker brings to the subject. For those who have not had that privilege, this book provides lasting opportunity to visit with a master.
— Eugene H. Levy, Rice University

Low

This is a unique undertaking by a scientist who is one of the most accomplished and outstanding in our field. The book takes the reader from the elementary principles of Newtonian mechanics and Maxwell's equations to hydrodynamics and magnetohydrodynamics equations. The author has intended this book to be conversations, as the title indicates. The style is informal but the physical ideas and concepts are presented with precision.
— B. C. Low, National Center for Atmospheric Research

Peter Goldreich

This small book, which describes the basic physics that governs the electrodynamics of the cosmos, is graced by insights the author gleaned during a lifelong fascination with the subject matter. We owe to him the explanation of many natural phenomena including how the solar wind blows and why its magnetic field lines form Archimedian spirals. Another of his creations, the a-? dynamo model affords us our understanding of how the magnetic fields of planets are maintained against resistive decay and why the Sun's magnetic field reverses every eleven years.
— Peter Goldreich, Institute for Advanced Study, Princeton

David Spergel

Parker is one of the leaders in the field and has his own novel approach to plasma astrophysics. I believe that both students and active researchers will benefit from this book.
— David Spergel, Princeton University

From the Publisher

"Nobody has contributed more, or more deeply, to our understanding of the physics of astrophysical magnetofluids than Eugene Parker. Conversations on Electric and Magnetic Fields in the Cosmos provides those of us who have had the privilege of learning directly from him a chance to revisit the elegant insight, structure, and breezy wit that Parker brings to the subject. For those who have not had that privilege, this book provides lasting opportunity to visit with a master."—Eugene H. Levy, Rice University

"This small book, which describes the basic physics that governs the electrodynamics of the cosmos, is graced by insights the author gleaned during a lifelong fascination with the subject matter. We owe to him the explanation of many natural phenomena including how the solar wind blows and why its magnetic field lines form Archimedian spirals. Another of his creations, the α-Ω dynamo model affords us our understanding of how the magnetic fields of planets are maintained against resistive decay and why the Sun's magnetic field reverses every eleven years."—Peter Goldreich, Institute for Advanced Study, Princeton

"This is a book by one of the leaders in the field of plasma astrophysics. Parker sets the record straight on many misunderstandings concerning electric and magnetic fields in the cosmos. The book also presents a revealing picture of the author's thinking and displays how he was able to arrive at such original solutions to so many important astrophysical problems."—Russell M. Kulsrud, author of Plasma Physics for Astrophysics

"This is a unique undertaking by a scientist who is one of the most accomplished and outstanding in our field. The book takes the reader from the elementary principles of Newtonian mechanics and Maxwell's equations to hydrodynamics and magnetohydrodynamics equations. The author has intended this book to be conversations, as the title indicates. The style is informal but the physical ideas and concepts are presented with precision."—B. C. Low, National Center for Atmospheric Research

"Parker is one of the leaders in the field and has his own novel approach to plasma astrophysics. I believe that both students and active researchers will benefit from this book."—David Spergel, Princeton University

Kulsrud

This is a book by one of the leaders in the field of plasma astrophysics. Parker sets the record straight on many misunderstandings concerning electric and magnetic fields in the cosmos. The book also presents a revealing picture of the author's thinking and displays how he was able to arrive at such original solutions to so many important astrophysical problems.
— Russell M. Kulsrud, author of "Plasma Physics for Astrophysics"

Editorial Reviews

"I shall strongly recommend my students to read this book in addition to their standard reading . . . not only to clarify their understanding of cosmic magnetism but also to learn how to present their ideas in a clear and understandable way."—-Dimitri Sokoloff, Journal of Geophysical and Astrophysical Fluid Dynamics

From the Publisher

I shall strongly recommend my students to read this book in addition to their standard reading . . . not only to clarify their understanding of cosmic magnetism but also to learn how to present their ideas in a clear and understandable way.

Journal of Geophysical and Astrophysical Fluid Dynamics - Dimitri Sokoloff

I shall strongly recommend my students to read this book in addition to their standard reading . . . not only to clarify their understanding of cosmic magnetism but also to learn how to present their ideas in a clear and understandable way.
— Dimitri Sokoloff

Journal of Geophysical and Astrophysical Fluid Dynamics