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Particle Diffusion in the Radiation Belts
368
BOOK REVIEWS
brief mention of the use of continental geometry. Only 5 pages are devoted to palaeomagnetism, this appears rather inadequate in view of the weight of evidence provided by the technique. However, several other excellent texts are available, some of which are referenced at the end of this chapter. The authors’ use of the terms ‘virtual’ when describing pole positions is very misleading, one had hoped that pole terminology was settled several years ago. In the section on sea-floor spreading, the phenomenon of field-reversals and the origin of the magnetic anomaly patterns observed across the sea floor are presented in descriptive form. One may regret that, in a book which generally emphasises the importance of the analytical approach, more attention has not been focussed on the analytical techniques involved in reduction of the marine magnetic data. In Chapter 14 (the shortest chapter with 11 pages) some broad conclusions are drawn from the geophysical and geochemical data presented earlier about the composition of the earth. The origin of seawater and the development of the atmosphere are also discussed, ‘The Representation of Structure’ is described in the 20 page appendix. There are several spelling and grammatical errors throughout the book, brackets omitted from an equation in Chapter 4, two diagrams in Chapter 9 are obviously incomplete and a temperature range given in Chapter 11 is inadequately defined. This well illustrated book remains a significant achievement in its presentation of physical geology and the authors are to be congratulated upon their approach which may not be met with the approval of the entire geological fraternity. However, the analytical treatment given to most chapters in the book clearly demonstrates the direction that teaching in the geological sciences will pursue in future years. —
B.J.J. EMBLETON (Canberra)
Particle Diffusion in the Radiation Belts. M. Schulz and L.J. Lanzerotti. Springer, Berlin, Heidelberg, New York, 1974,215 pp., DM78.—. (Volume 7 in the series Physics and Chemistry in Space, edited by J.G. Roederer.) This book is part of a series of monographs written to provide concise and up-to-date information on
various aspects of space exploration. Dr. Schulz writes on the theoretical aspects of the subject and Dr. Lanzerotti on the experimental data and its analysis. Both authors are well-known in the literature of the subject and are particularly well qualified to write on this topic. After an Introduction which outlines the types of physics that occur within the magnetosphere of the earth, the book starts by establishing the adiabatic invariants of particle motion in the magnetosphere, and then considers, at some length, the structure of the earth’s field and its interaction with the solar wind. This detailed discussion is necessary since it is the earth’s magnetic field and its behaviour which controls magnetospheric phenomena. Having established this framework, the book then shows how diffusion processes occur due to breakdown of the appropriate adiabatic invariants. For convenience of treatment the main processes are subdivided into pitch angle diffusion and radial diffusion, although a brief mention is made of non-diffusive processes,e.g. charge exchange effects. The chapter on pitch angle diffusion is largely devoted to wave—particle effects. In view ofthe cornplexity of the equations, this part of the book is very well done, with the essential physical effects brought out without their drowning in a sea of symbols. The whole presentation reflects the confidence that is now felt that there is a good understanding of the wave—particle interactions actually taking place in the magnetosphere. The processes involved in radial diffusion are less well known than for pitch angle diffusion, and this reflects itself in the rather more wide ranging discussion about radial diffusion. However, once again it is very well done and the essential physics clearly brought out, although some of the problems associated with the inner belt protons are somewhat glossed over. The remaining chapters of the book are devoted to examples of data which clearly show some of the effects already discussed theoretically, and a discussion of how to analyse satellite data for diffusion effects. This part of the book suffers from the basic problem of experimental physics; it is fragmentary and full of qualifications. Thus after the smooth flow of theoretical exposition the book rather hops from data sample to data sample. Such a situation is inevitable, and the authors are right to get the theoretical
BOOK REVIEWS
369
basis clear before introducing the data. The overall emphasis is on electron data, mainly from the outer dipolar part of the magnetosphere. This is reasonable, given that the progress in wave— particle interaction in recent years has been largely in this region and that research effort has concentrated in looking for sources of high-energy magnetospheric particles, which are expected to be in the outer region. The chapter on techniques of analysis is the least satisfactory in that, while it has some good general points to make, it returns again and again to the need to ‘select’ the data to make a particular analysis possible. Given the many competing processes occurring, such selection is critical and can only be learnt the hard way by experience! Overall this is a good book. It serves as a good introduction to the subject to a new worker in the field, and a very useful summary to those already in it. The authors are to be complemented on the way in which they have covered the theoretical and experimental part of the subject, and their publishers on the very high typographical standard maintained throughout the book. —
R.J. HYNDS (London)
Chemistry of the Earth. Karl K. Turekian. Holt, Rinehart and Winston, New York, 1974, 131 pp., £2.—. This book is one of a series on ‘Physical Sciences and Technology’ and is in content and style directed at those on the borders of science, either at late secondary or introductory tertiary level in formal education. The first three chapters (The Elements; Abundance and Origin of the Elements; The Chemical Bond) are basic science presented in readable style and give a useful glimpse both of accepted fundamental information and areas, such as nucleosynthesis, where there remains room for hypotheses and speculation. Chapters on ‘Minerals’ and ‘Rocks’ lead to chapters 6 (The Earth as a Planet) and 8 (The Evolution of the Earth) which covers the major descriptive aspects of the earth, with some emphasis on distinction between processes dominated by secular change through earth history and others by recycling processes. The geochemical requirements for recycling of sedimentary materials
are used to lead into brief description of major tectomc processes within the framework of plate-tectonics models. The brief chapter 7 (The Radioactivity Clock) provides a link relating the geophysical and geochemical view of the earth as now constituted and the geological evolution of the earth. A final chapter (4 pages) on the interaction of man with his environment and an Appendix ‘Chemical Equilibrium and Phase Diagrams’ add little of substance and are somewhat out of context with the rest of the book one suspects these are part of a particular course, one in response to current social pressures and the other because it is felt to be a basic aspect of chemistry of the earth. Most of the book is readable and could obviously form a text in an introductory ‘Science’ course. There are references for text books in each of the subject areas sketched out and the style of the book certainly emphasises the existence of unanswered questions and the inter-related nature of many disciplines in seeking understanding of the earth. Most line draw. ings are clear and informative, but some half-tones of rocks and scenery serve little purpose. The reproduction of figures from research papers in some cases results in diagrams whose complexity is not in keeping with the simplicity of the text. It is, in fact, characteristic of the book that it presents some material suited for introductory science courses followed rapidly by sections understandable only by advanced students in the field this is particularly true of chapters 1—4. This approach renders the book unsuited as a comprehensive course basis at any level, except that it may achieve a purpose as an ‘aperitif’ or part of a motivation-oriented course for preuniversity or introductory university levels. In summary, a small introductory text suited for senior high school or introductory university courses at the general educationlevel with the characteristic that it contains material which the student will understand and parts which will be beyond his comprehension, but may motivate curiosity. —
—
D.H. GREEN (Canberra)
Stars and the Milky Way System. L.N. Mavridis (Editor). Springer, Berlin, Heidelberg, New York, 1974, 368 pp., DM 158,—. (Proceedings of the First
BOOK REVIEWS
brief mention of the use of continental geometry. Only 5 pages are devoted to palaeomagnetism, this appears rather inadequate in view of the weight of evidence provided by the technique. However, several other excellent texts are available, some of which are referenced at the end of this chapter. The authors’ use of the terms ‘virtual’ when describing pole positions is very misleading, one had hoped that pole terminology was settled several years ago. In the section on sea-floor spreading, the phenomenon of field-reversals and the origin of the magnetic anomaly patterns observed across the sea floor are presented in descriptive form. One may regret that, in a book which generally emphasises the importance of the analytical approach, more attention has not been focussed on the analytical techniques involved in reduction of the marine magnetic data. In Chapter 14 (the shortest chapter with 11 pages) some broad conclusions are drawn from the geophysical and geochemical data presented earlier about the composition of the earth. The origin of seawater and the development of the atmosphere are also discussed, ‘The Representation of Structure’ is described in the 20 page appendix. There are several spelling and grammatical errors throughout the book, brackets omitted from an equation in Chapter 4, two diagrams in Chapter 9 are obviously incomplete and a temperature range given in Chapter 11 is inadequately defined. This well illustrated book remains a significant achievement in its presentation of physical geology and the authors are to be congratulated upon their approach which may not be met with the approval of the entire geological fraternity. However, the analytical treatment given to most chapters in the book clearly demonstrates the direction that teaching in the geological sciences will pursue in future years. —
B.J.J. EMBLETON (Canberra)
Particle Diffusion in the Radiation Belts. M. Schulz and L.J. Lanzerotti. Springer, Berlin, Heidelberg, New York, 1974,215 pp., DM78.—. (Volume 7 in the series Physics and Chemistry in Space, edited by J.G. Roederer.) This book is part of a series of monographs written to provide concise and up-to-date information on
various aspects of space exploration. Dr. Schulz writes on the theoretical aspects of the subject and Dr. Lanzerotti on the experimental data and its analysis. Both authors are well-known in the literature of the subject and are particularly well qualified to write on this topic. After an Introduction which outlines the types of physics that occur within the magnetosphere of the earth, the book starts by establishing the adiabatic invariants of particle motion in the magnetosphere, and then considers, at some length, the structure of the earth’s field and its interaction with the solar wind. This detailed discussion is necessary since it is the earth’s magnetic field and its behaviour which controls magnetospheric phenomena. Having established this framework, the book then shows how diffusion processes occur due to breakdown of the appropriate adiabatic invariants. For convenience of treatment the main processes are subdivided into pitch angle diffusion and radial diffusion, although a brief mention is made of non-diffusive processes,e.g. charge exchange effects. The chapter on pitch angle diffusion is largely devoted to wave—particle effects. In view ofthe cornplexity of the equations, this part of the book is very well done, with the essential physical effects brought out without their drowning in a sea of symbols. The whole presentation reflects the confidence that is now felt that there is a good understanding of the wave—particle interactions actually taking place in the magnetosphere. The processes involved in radial diffusion are less well known than for pitch angle diffusion, and this reflects itself in the rather more wide ranging discussion about radial diffusion. However, once again it is very well done and the essential physics clearly brought out, although some of the problems associated with the inner belt protons are somewhat glossed over. The remaining chapters of the book are devoted to examples of data which clearly show some of the effects already discussed theoretically, and a discussion of how to analyse satellite data for diffusion effects. This part of the book suffers from the basic problem of experimental physics; it is fragmentary and full of qualifications. Thus after the smooth flow of theoretical exposition the book rather hops from data sample to data sample. Such a situation is inevitable, and the authors are right to get the theoretical
BOOK REVIEWS
369
basis clear before introducing the data. The overall emphasis is on electron data, mainly from the outer dipolar part of the magnetosphere. This is reasonable, given that the progress in wave— particle interaction in recent years has been largely in this region and that research effort has concentrated in looking for sources of high-energy magnetospheric particles, which are expected to be in the outer region. The chapter on techniques of analysis is the least satisfactory in that, while it has some good general points to make, it returns again and again to the need to ‘select’ the data to make a particular analysis possible. Given the many competing processes occurring, such selection is critical and can only be learnt the hard way by experience! Overall this is a good book. It serves as a good introduction to the subject to a new worker in the field, and a very useful summary to those already in it. The authors are to be complemented on the way in which they have covered the theoretical and experimental part of the subject, and their publishers on the very high typographical standard maintained throughout the book. —
R.J. HYNDS (London)
Chemistry of the Earth. Karl K. Turekian. Holt, Rinehart and Winston, New York, 1974, 131 pp., £2.—. This book is one of a series on ‘Physical Sciences and Technology’ and is in content and style directed at those on the borders of science, either at late secondary or introductory tertiary level in formal education. The first three chapters (The Elements; Abundance and Origin of the Elements; The Chemical Bond) are basic science presented in readable style and give a useful glimpse both of accepted fundamental information and areas, such as nucleosynthesis, where there remains room for hypotheses and speculation. Chapters on ‘Minerals’ and ‘Rocks’ lead to chapters 6 (The Earth as a Planet) and 8 (The Evolution of the Earth) which covers the major descriptive aspects of the earth, with some emphasis on distinction between processes dominated by secular change through earth history and others by recycling processes. The geochemical requirements for recycling of sedimentary materials
are used to lead into brief description of major tectomc processes within the framework of plate-tectonics models. The brief chapter 7 (The Radioactivity Clock) provides a link relating the geophysical and geochemical view of the earth as now constituted and the geological evolution of the earth. A final chapter (4 pages) on the interaction of man with his environment and an Appendix ‘Chemical Equilibrium and Phase Diagrams’ add little of substance and are somewhat out of context with the rest of the book one suspects these are part of a particular course, one in response to current social pressures and the other because it is felt to be a basic aspect of chemistry of the earth. Most of the book is readable and could obviously form a text in an introductory ‘Science’ course. There are references for text books in each of the subject areas sketched out and the style of the book certainly emphasises the existence of unanswered questions and the inter-related nature of many disciplines in seeking understanding of the earth. Most line draw. ings are clear and informative, but some half-tones of rocks and scenery serve little purpose. The reproduction of figures from research papers in some cases results in diagrams whose complexity is not in keeping with the simplicity of the text. It is, in fact, characteristic of the book that it presents some material suited for introductory science courses followed rapidly by sections understandable only by advanced students in the field this is particularly true of chapters 1—4. This approach renders the book unsuited as a comprehensive course basis at any level, except that it may achieve a purpose as an ‘aperitif’ or part of a motivation-oriented course for preuniversity or introductory university levels. In summary, a small introductory text suited for senior high school or introductory university courses at the general educationlevel with the characteristic that it contains material which the student will understand and parts which will be beyond his comprehension, but may motivate curiosity. —
—
D.H. GREEN (Canberra)
Stars and the Milky Way System. L.N. Mavridis (Editor). Springer, Berlin, Heidelberg, New York, 1974, 368 pp., DM 158,—. (Proceedings of the First