Theoretical Physics And Astrophysics | V. L. Ginzburg

There are many textbooks of theoretical physics among which the many- volume work of Landau and Lifshitz is the best known and most outstanding* It is impossible, however, to deal with all problems in such a course. Moreover, even the problems which are considered can usually not be looked at from dif­ferent points of view. At the same time, depending on their peculiar abilities,

the nature of their training, natural inclinations, and so on, different people often prefer different approaches, arguments, examples, and proofs.

A natural possibility to satisfy an existing need is, clearly, to publish dif­ferent textbooks and, in particular, different supplementary textbooks which are devoted to separate problems, aspects, and methods rather than to a syste­matic exposition of a topic. Such supplementary texts differ in principle

from the systematic ones in that the choice of material to a large extent is not predetermined. One can say the same about the style and nature of the exposition whereas in a systematic textbook one must impose very rigid restric­tions with respect to conciseness, content of technical methods, unified notation, and so on. The present book is just such a supplementary text which is devoted to a few problems in theoretical physics and astrophysics. From the table of contents it is immediately clear, but we may also state it that, in general, we are dealing with problems which are in one way or other connec­ted with electrodynamics.

The basis of the exposition was a lecture course for students in the physics and astrophysics departments of the Moscow Physico-Technical Institute. These lectures were not meant to replace a systematic course and had just the charac­ter of ’capita selecta' taking into account the interests of the department and not least the interests and capabilities of the author. Of course, we are not saying that the problems which the author at a particular moment in the page was occupied with are more important or more interesting than many other

It is simply the case that merely presenting ’more or less moved by the spi material with which he is well familiar, the author may perhaps hope to suppK ment existing texts and monographs without checking whether he is rewriting

to some extent duplicating them.

As to the nature of the exposition one should note that we are dealing here not with lectures which are written out but with a special text specially pre­ pared for these lectures, in which rather often we have also included material which is not very suitable and in fact was not used for the lectures themselves

(that is, for the oral presentation). In this respect the book is in style close to a monograph or a review article which finds reflection also in the rather large number of references to the literature. As amongst those there is a large number of references to work by the author, we emphasize that this, like the choice of material, is completely unconnected with any pretentions, but caused by the tendency, already mentioned, to touch only upon very familiar problems which were dealt with in detail in the papers referred to; moreover,

a whole number of such papers were used directly in the text.

We note, finally, that the book is definitely not intended for people with a mathematical inclination — such as ’pure* theoretical physicists. The excep­tionally large role played by mathematics in theoretical physics is completely unquestionable and natural, but aiming at mathematical generality and rigour

is by far not always justified — one must pay for this. It is generally known, in particular, that most new physical results have been obtained by relatively simple means while the 'mathematization' occurred only in the later stages. At any rate, physics, and not mathematics is the main point of theoretical physics. An exposition of theoretical problem with a 'general physics' bias is at least as permissible as the nowadays more widely propagated tendency to mathematical perfection.

One may hope that this book will turn out to be useful for graduate students and also for post-doctoral and research workers.