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Gravitation and relativity
Book Reviews cellent review chapter, "Properties of Solids and Liquids" (E. C. Crittenden, Jr.), covers the extensive territory between lattice specific heats, lattice and electronic thermal conductivities, electrical conduction in metals, semi-conductors and liquids, the properties of liquid helium, and the mechanical properties of engineering materials. Areas of engineering activity receiving particular attention are "Insulation Technology" (R. H. Kropschot), "Cryogenic Pumping and Space Simulation" (E. L. Garwin), and "Nuclear Propulsion" (F. J. Edeskuty). The influence of the space program on cryogenic engineering is made clear in the two chapters, "Cryogenic Aspects of Deep Space Probes" (K. A. Ehrike) and "Cryogenic Problems in Space" (M. Aden berg). The final chapter, "Cryobiology" (A. P. Rinfret), introduces an area of current research activity that may well lead to important technological applications in the not too distant future. "Cryogenic Technology" provides an extensive introduction to the many topics in science and engineering that are concerned with or affected by cryogenic phenomena. While the discussion is largely qualitative, it is far from elementary. Any weaknesses arising from the attempt to cover too much territory are more than offset by the generally high level of presentation and the lengthy lists of reference provided by the authors. JAMES NICOL
Cryonetics Corporation Burlington, Massachusetts GRAVITATION AND RELATIVITY, edited by Hong-Yee Chin and William F. Hoffman. 353 pages, diagrams, illustrations, 6 X 9 in. New York, W. A. Benjamin, Inc. 1963. Price $15.75.
This work on gravitation and the general theory of relativity is of a different type from the usual books on this subject. The special theory of relativity arose as a result of the 'failure of all the experiments made to detect the motion of the earth through the aether. Through the efforts of Fitzgerald, Lorentz, Poincar6 and, most of all, Einstein, these null results were satisfactorily explained, but only at the cost of profoundly modifying our concepts of space and time. Throughout this development the dependence of theory on experiment was always uppermost in the minds
616
of the theoreticians. But the impetus to develop the general theory of relativity did not come from experiment and observation. Rather the difficulty that led to the development of the general theory was entirely logical. In the special theory of relativity we had given up the classical concept of an absolute space, but we had not put all coordinate systems on an equal basis for expressing the fundamental laws of nature. This was considered to be philosophically unsatisfactory. After about ten years of effort, Einstein succeeded in overcoming this defect of the special theory of relativity by generalizing Minkowski's brilliant concept of space-time, thereby producing the general theory of relativity, in which all coordinate systems are equivalent for expressing the laws of physics. This was a very great achievement from a logical and philosophic point of view. But the consequences for experimental physics were minute indeed. After Einstein developed his general theory of relativity, other such theories were developed. The subject of general relativity and the associated cosmological problems became for a long time a favorite subject of research by scientists who were professional mathematicians rather than professional physicists. The connection with experimentation and observation was remote and the emphasis on ~ priori assumptions was great. The book under review here approaches the subjects of gravitation and the general theory of relativity in a more open-minded, critical and experimental mood than was customary heretofore. Although the fundamental concepts of space-time and Riemannian geometry are assumed to be valid, the effort is made to ascertain all the possible varieties of fundamental theory that are possible on the basis of our present observational and experimental knowledge. Furthermore, in recent times additional experiments have been made to improve our knowledge of the geometry of spacetime. The basic concepts and postulates of general relativity are subjected to a theoretical analysis. Considerable space is devoted to the Mach principle. The authors stress the point that there is no agreement as to the meaning or even the validity of the Mach principle. In ,fact, there are a number of basic items connected with the general theory of relativity on which the experts disagree. One of the controversial subjects is the relation of general relativity
Journal of The Franklin In~itute
Book Reviews and q u a n t u m mechanics. Other subjects considered are a possible variation of the universal constant of gravitation G with time and the effect of such a variation on astronomy and geophysics. Gravitational waves are also discussed extensively as well as the concept of critical masses as related to astrophysics. This book is written by outstanding experts and should be required reading for all who wish to be up-to-date on the subject.
rather whimsical nature. To this reviewer, this book is one of t h e more interesting in its field to appear in recent years. I t is worth serious consideration from anyone faced with teaching the subject of linear circuits to college juniors, although the price seems higher t h a n competing b0olcs in the field.
ENos E. WITMER
Ralph Deutsch. 410 pages, diagrams, 6 X 9 in. Englewood Cliffs, N. J., Prentice-Hall, Inc., 1963. Price, $16.00.
University of Pennsylvania LINEAR CIRCUIT ANALYSIS, b y Gerhard F. Paskusz and B e r t r a m Russell. 359 pages, diagrams, 5-~ X 9 in. Englewood Cliffs, N. J., Prentice-Hall, Inc., 1964. Price, $15.00. This iunior level textbook is another which follows the current trend in making an att e m p t to show the essential similarity of what were once considered as separate branches of engineering. Here is given a single coherent t r e a t m e n t of the analysis of linear systems made up of lumped elements. I t is pointed out t h a t the same type of analysis applies whether the nature of the elements is electrical, translational mechanical, rotational me~ chanical, acoustical or thermal. Systems composed of elements of more t h a n one of these types are also considered. I n order to emphasize the essential unity, the authors choose to define three parameters which relate the force and response variables of the system. An alpha parameter relates force to time derivative of response; a beta parameter relares force to response; a gamma parameter relates force to time integral of response. I n an electrical circuit, these parameters correspond to inductance, resistance, and capacitance. Whether the introduction of this additional set of parameters to those normally used in describing physical systems is actually helpful to the beginning student, is something which can be decided only after it has been tried a t length. The range of subject matter is typical of a book of this level, and includes the setting up of equations, solution b y the Laplace transform, steady state solution, power and energy concepts, circuit theorems, resonance phenomena, and Fourier analysis. A large n u m b e r of practice problems are provided, some fo a
Vol. 277, No. 6, June 1964
W. J. CUNNINGHAM
Yale University
ORBITAL DYNAMICS OF SPACE VEHICLES,b y
This book fills an i m p o r t a n t need for an upto-date text book in space vehicle dynamics. The interesting feature of the book is the seemingly complete absence of the phrase "it can be shown." The author guides the reader step-by-step in arriving at each result. Chapter II, " T h e Geometry of Special Orbits," offers excellent reading. The choice of a particular reference frame, while describing the motion of a space vehicle, is very important. The author goes through a cross section of possible reference frames for the study of orbital motion. Chapters 6 and 7, "Elements of Analytical Dynamics" and "Analytical Perturbations," are rather sketchy and appear to add little to the knowledge when compared to a t r e a t m e n t on the same subject given in standard books, such as "Principles of Mechanics" b y Synge and Griffith. I n addition, some of the notations used are at times rather difficult to follow. Chapter 8 is a good addition in helping to clarify the material in chapters 6 and 7. Chapters 11 and 12 provide an elementary study of measurement and detection technique in a minimum of pages. All in all the author is to be commended for his work. NARINDRA N. PURl
Drexel Institute of Technology NETWORK ANALYSIS AND SYNTHESIS, b y Louis Weinberg. 692 pages, diagrams, 6 X 9 in. New York, McGraw-HiU Book Co., Inc., 1962. Price, $19.50. The field of network synthesis has witnessed a rapid growth within the past twenty yeats. However, much of the work done has, in a scattered fashion, appeared only in technical journals, providing the necessity for a textbook
617
Cryonetics Corporation Burlington, Massachusetts GRAVITATION AND RELATIVITY, edited by Hong-Yee Chin and William F. Hoffman. 353 pages, diagrams, illustrations, 6 X 9 in. New York, W. A. Benjamin, Inc. 1963. Price $15.75.
This work on gravitation and the general theory of relativity is of a different type from the usual books on this subject. The special theory of relativity arose as a result of the 'failure of all the experiments made to detect the motion of the earth through the aether. Through the efforts of Fitzgerald, Lorentz, Poincar6 and, most of all, Einstein, these null results were satisfactorily explained, but only at the cost of profoundly modifying our concepts of space and time. Throughout this development the dependence of theory on experiment was always uppermost in the minds
616
of the theoreticians. But the impetus to develop the general theory of relativity did not come from experiment and observation. Rather the difficulty that led to the development of the general theory was entirely logical. In the special theory of relativity we had given up the classical concept of an absolute space, but we had not put all coordinate systems on an equal basis for expressing the fundamental laws of nature. This was considered to be philosophically unsatisfactory. After about ten years of effort, Einstein succeeded in overcoming this defect of the special theory of relativity by generalizing Minkowski's brilliant concept of space-time, thereby producing the general theory of relativity, in which all coordinate systems are equivalent for expressing the laws of physics. This was a very great achievement from a logical and philosophic point of view. But the consequences for experimental physics were minute indeed. After Einstein developed his general theory of relativity, other such theories were developed. The subject of general relativity and the associated cosmological problems became for a long time a favorite subject of research by scientists who were professional mathematicians rather than professional physicists. The connection with experimentation and observation was remote and the emphasis on ~ priori assumptions was great. The book under review here approaches the subjects of gravitation and the general theory of relativity in a more open-minded, critical and experimental mood than was customary heretofore. Although the fundamental concepts of space-time and Riemannian geometry are assumed to be valid, the effort is made to ascertain all the possible varieties of fundamental theory that are possible on the basis of our present observational and experimental knowledge. Furthermore, in recent times additional experiments have been made to improve our knowledge of the geometry of spacetime. The basic concepts and postulates of general relativity are subjected to a theoretical analysis. Considerable space is devoted to the Mach principle. The authors stress the point that there is no agreement as to the meaning or even the validity of the Mach principle. In ,fact, there are a number of basic items connected with the general theory of relativity on which the experts disagree. One of the controversial subjects is the relation of general relativity
Journal of The Franklin In~itute
Book Reviews and q u a n t u m mechanics. Other subjects considered are a possible variation of the universal constant of gravitation G with time and the effect of such a variation on astronomy and geophysics. Gravitational waves are also discussed extensively as well as the concept of critical masses as related to astrophysics. This book is written by outstanding experts and should be required reading for all who wish to be up-to-date on the subject.
rather whimsical nature. To this reviewer, this book is one of t h e more interesting in its field to appear in recent years. I t is worth serious consideration from anyone faced with teaching the subject of linear circuits to college juniors, although the price seems higher t h a n competing b0olcs in the field.
ENos E. WITMER
Ralph Deutsch. 410 pages, diagrams, 6 X 9 in. Englewood Cliffs, N. J., Prentice-Hall, Inc., 1963. Price, $16.00.
University of Pennsylvania LINEAR CIRCUIT ANALYSIS, b y Gerhard F. Paskusz and B e r t r a m Russell. 359 pages, diagrams, 5-~ X 9 in. Englewood Cliffs, N. J., Prentice-Hall, Inc., 1964. Price, $15.00. This iunior level textbook is another which follows the current trend in making an att e m p t to show the essential similarity of what were once considered as separate branches of engineering. Here is given a single coherent t r e a t m e n t of the analysis of linear systems made up of lumped elements. I t is pointed out t h a t the same type of analysis applies whether the nature of the elements is electrical, translational mechanical, rotational me~ chanical, acoustical or thermal. Systems composed of elements of more t h a n one of these types are also considered. I n order to emphasize the essential unity, the authors choose to define three parameters which relate the force and response variables of the system. An alpha parameter relates force to time derivative of response; a beta parameter relares force to response; a gamma parameter relates force to time integral of response. I n an electrical circuit, these parameters correspond to inductance, resistance, and capacitance. Whether the introduction of this additional set of parameters to those normally used in describing physical systems is actually helpful to the beginning student, is something which can be decided only after it has been tried a t length. The range of subject matter is typical of a book of this level, and includes the setting up of equations, solution b y the Laplace transform, steady state solution, power and energy concepts, circuit theorems, resonance phenomena, and Fourier analysis. A large n u m b e r of practice problems are provided, some fo a
Vol. 277, No. 6, June 1964
W. J. CUNNINGHAM
Yale University
ORBITAL DYNAMICS OF SPACE VEHICLES,b y
This book fills an i m p o r t a n t need for an upto-date text book in space vehicle dynamics. The interesting feature of the book is the seemingly complete absence of the phrase "it can be shown." The author guides the reader step-by-step in arriving at each result. Chapter II, " T h e Geometry of Special Orbits," offers excellent reading. The choice of a particular reference frame, while describing the motion of a space vehicle, is very important. The author goes through a cross section of possible reference frames for the study of orbital motion. Chapters 6 and 7, "Elements of Analytical Dynamics" and "Analytical Perturbations," are rather sketchy and appear to add little to the knowledge when compared to a t r e a t m e n t on the same subject given in standard books, such as "Principles of Mechanics" b y Synge and Griffith. I n addition, some of the notations used are at times rather difficult to follow. Chapter 8 is a good addition in helping to clarify the material in chapters 6 and 7. Chapters 11 and 12 provide an elementary study of measurement and detection technique in a minimum of pages. All in all the author is to be commended for his work. NARINDRA N. PURl
Drexel Institute of Technology NETWORK ANALYSIS AND SYNTHESIS, b y Louis Weinberg. 692 pages, diagrams, 6 X 9 in. New York, McGraw-HiU Book Co., Inc., 1962. Price, $19.50. The field of network synthesis has witnessed a rapid growth within the past twenty yeats. However, much of the work done has, in a scattered fashion, appeared only in technical journals, providing the necessity for a textbook
617