Physics topics

by Dr. J. B. Tatum


Stellar Atmospheres

Celestial Mechanics

Classical Mechanics

Geometric Optics

Electricity and Magnetism

Heat and Thermodynamics

Physical Optics

Max Fairbairn's Planetary Photometry

Integrals and Differential Equations


    On retirement from teaching I found myself throwing out what must have been literally tons of paper accumulated over the years, and it seemed a bit of a waste. Then someone suggested that, rather than throwing it all away, I should put some of it on the Web, where students might find a use for it. I accepted that suggestion and I have started by putting together a few topics from two rather separate subjects, namely Stellar Atmospheres and Classical Mechanics. I had also at one time started work on what was originally intended to be a rather more systematic and thorough book on Celestial Mechanics. I have decided instead to put that on the Web, too, a chapter or two at a time. The "book" on Celestial Mechanics is planned to be in two distinct parts. The first part will not have any astronomy in it, but will contain merely some mathematical preambles such as a review of some numerical methods, plane and spherical trigonometry and conic sections. In the second part we move on to astronomical topics. When this is completed (which may be a while yet!) the reader should, among other things, be able to compute orbits and ephemerides of planets, asteroids and comets. Of course, computer packages have been available for a long time now that enable anyone to do these things - but without any understanding on the part of the user. It is hoped that the reader will find it more intellectually satisfying to understand the fundamental principles and will then be able to write computer problems of his or her own.

    Some time after I had been working on these three topics, a former student persuaded me that he found my method of doing lens and mirror calculations helpful, so more of less as an afterthought I have recently added the beginnings of a new topic, namely Geometric Optics. Yet other topics, such as Electricity and Magnetism, or perhaps Thermodynamics, may follow at a later date if the spirit moves me.

    From time to time I shall add additional chapters, as the spirit moves me, so, if you find any of the present material helpful, you are welcome to keep an eye open for additional material if and when it appears. All three "books" are "under development" and likely to remain so for some time.

    None of these notes are intended to substitute for or to be used in conjunction with any course a student may be taking or any book s/he may be studying. Nevertheless, if they help at all in aiding a reader to understand something, it will have been worth the effort.

    When I started to do this, I had had absolutely no experience with using a Personal Computer (PC), and it took some time for me to learn even the basics. It will be obvious, for example, especially in the earlier chapters, that I have not yet mastered the art of making drawings on a computer, and many of the drawings are, to use a somewhat generous word, inadequate. I apologize for that, but it may in fact even have some pedagogical value in that my inadequate drawings may force the reader to do better him- or herself, and so in the end gain a better understanding than if my drawings had been perfect in the first place. Well, that is the excuse I am offering, anyway!

    There are advantages and disadvantages to having academic material on the Web rather than in a book. A book is subject to very strict refereeing and editorial review, and a huge effort is made to make it as error-free as possible. A reader can have confidence that the material presented is sound and reliable. There is no such control on the Web, and anyone can put anything he wants there. Consequently, you have no guarantee that what you will find in these notes isn't rubbish from beginning to end. I hope and believe, however, that this is not the case. To counterbalance this drawback of Web material is the advantage that if mistakes are detected, they are easily corrected - but only if the author is made aware of them. You, the reader, are the most likely person to find any mistakes, so, if you spot any, or if you find some passages that are not as clear as you would like, or you would like some clarification, please do write to me at and let me know, so that I can make any corrections or clarify the text if need be.

    I would like to take the opportunity of thanking the many people who have helped to teach me how to use a computer and to get this material together for the Web, especially Geri Richmond, Menno Hubregse, David Balam and Jason Stumpf as well as many others whom I have bugged from time to time with questions about how to do this or how to do that. I am also extremely grateful to Max Fairbairn of Sydney, Australia, and Peter Michaux of Victoria, Canada, who have read through much of the text and have found and enabled me to correct a number of what would otherwise have been embarrassing mistakes.

Texts © 2000 - 2004 Dr. J. B. Tatum
Web page design and code © 2002 - 2004 Jason Stumpf