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Arbie's Unoriginally Titled Book Blog

It's a blog! Mainly of book reviews.

Currently reading

Basics of Plasma Astrophysics
Claudio Chiuderi, Marco Velli
Progress: 58/250 pages
Ursula K. Le Guin: The Complete Orsinia: Malafrena / Stories and Songs (The Library of America)
Brian Attebery, Ursula K. Le Guin
Progress: 454/700 pages
Aurora: In Search of the Northern Lights
Melanie Windridge
Progress: 205/320 pages
A Student's Guide to Lagrangians and Hamiltonians
Patrick Hamill
Progress: 7/180 pages
Complete Poems, 1904-1962
E.E. Cummings
Progress: 164/1102 pages
The Complete Plays and Poems
E.D. Pendry, J.C. Maxwell, Christopher Marlowe
She Stoops to Conquer and Other Comedies (Oxford World's Classics)
Henry Fielding, David Garrick, Oliver Goldsmith
Progress: 159/448 pages
Gravitation (Physics Series)
Kip Thorne;Kip S. Thorne;Charles W. Misner;John Archibald Wheeler;John Wheeler
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I Am a Cat
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The Complete Novels of Jane Austen
Jane Austen
Progress: 651/1220 pages

An Introduction to Magnetohydrodynamics, P.A. Davidson

An Introduction to Magnetohydrodynamics - P.A. DAVIDSON, E.J. Hinch, S.H. Davis, Mark J. Ablowitz

So magnetohydrodynamics (MHD) is the (classical) theory of electrically conducting fluids, which divide neatly into liquid metals and plasmas. I'm not professionally interested in liquid metals so I skipped all the material that was solely applicable to them, which is possibly as much as half of it. It's also a microcosm of one of the many problems with the book -it's scope is way too large for it's size. To get anywhere with a topic that is defined as the merging of fluid mechanics and classical electrodynamics, one must have a thorough grounding in both those separate topics first. This book tries to cover that and does it badly because they need a book each. The physics of plasmas is very different from that of liquid metals but this book tries to cover both. So really we have four books' worth of material crammed into the space of only one. That's one problem.


Next there's the mathematical treatment, which is really poor. The subject requires a strong grasp of vector calculus. This is unavoidable. The fundamental equations of the theory are non-linear and form a large set that must be solved "self-consistently" whilst describing a dynamic (i.e. time varying) system. This also, is unavoidable. In other words this ain't no easy subject. That's no excuse for lax derivations, poor or absent definitions, or equations that are actually useless because one of the parameters in them has to be "chosen appropriately" (i.e. fudged) in every specific case, with no means of doing so so much as hinted at.


Finally, the verbal description of the physics is on occasions horrendously bad (and plain wrong). This is particularly so with regard to energy, which is repeatly "destroyed" throughout the book - a task nobody else has been able to accomplish in the history of physics. The author seems simply not to know what happens to the kinetic energy of the fluids he describes when it stops being obviously visible. Heat, man! Heat! Conservation of angular momentum is similarly and even more cavalierly treated.

I can't recommend this book to anybody, unfortunately.


I have a number of other books that treat MHD. In some it's an introductory chapter, in others it's in relation to a specific context (naturally occurring plasmas). Whether these will prove better remains to be seen.