Arbie's Unoriginally Titled Book Blog

Nice section on adiabatic invariants - although it doesn't explain why they are "adiabatic"!

Fierce warrior, great general, total prat.

Nobody believes the King but his Queen ends up in prison for adultery anyway.

The Informer.

Because the pagination works as Lecture No. - Page No. instead of just Page No. it's hard to say how far one is through this book. Hence the number above reflects the LECTURE NUMBER out of 42. I'm doing a re-read of this volume which is mainly classical electrodynamics.

At this point I would say that Chen's book is a better first text on plasma physics; this one assumes more maths. It's not bad, though, and covers topics not in Chen. We'll see how I get on with them later.

Are we there yet?

I think I'm making such slow progress with this that I've forgotten everything that's gone before...

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.

Oh dear! Leontes falsely suspects his wife of adultery. When Othello did that things  went really badly. What's gonna happen here?

This poem appears to be a distant ancestor of all those horror films where teen couples die horribly as a consequence of sneaking off to have illicit pre-marital sex. Our cultural obsession with virginity as a symbol of moral purity and an only marginally more subtle form of Patriarchal reduction of the female to property never ceases to amaze me. Yep, it's weaker in the West, now, than it has been historically, but it's still present in some quarters, as evidenced by those same horror movies, and there are many countries where it's still a Really Big Thing that you have to be a virgin on your wedding night. Maybe one day the Middle Ages will come to a close? Don't hold your breathe, though.

Marlowe either abandoned this poem incomplete in favour of other projects or died whilst still actively working on it, I don't know which, but either way, he only wrote the first ~1/3 (or less, haven't actually counted the pages) and George Chapman took up the task of completing the story. Unfortunately, on this evidence, Chapman was not nearly as talented as Marlowe - which is more informative than it might seem at face value. See, Marlowe (and all the other Elizabethan-Jacobean playwrights and poets) exists under the enormous and deep shadow cast by Shakespeare, who went from an early career as Marlovian imitator to towering genius of dramatic-poetic expression. What Chapman shows, however, is that the better known contemporaries of Shakespeare, such as Marlowe, Jonson and Middleton were actually talented in their own right - they just had the misfortune to overlap with the best there's ever been by a remarkable stretch. In fact Shakespeare wrote a lot of plays and numerous of these less celebrated authors wrote works that were as good as or better than Shakespeare's weaker efforts. Chapman's mediocrity serves to illustrate that Marlowe was actually excellent - he just had a rival who permanently skewed the chart of dramatic-poetic genius.

It's a fun poem, especially at the beginning (Marlowe's bit) and the end (sudden turn to the Tragic), particularly if you like tales of gods and heroes and can swallow the ridiculous moral of the tale.

Darwin is glad to be home after five years away on a journey meant only to take two.

The author continues to show a poor grip on the principle of conservation of energy: It's all very well to say that energy cascades downward in scale from larger to smaller eddies in a turbulent flow, because the energy is still kinetic energy. When one gets to the scale where "viscous effects" are important we're back to the mysterious "destruction" of the energy. IT IS NOT DESTROYED! Where does it REALLY go? Heat. Which is to say, if you put a stick in a bucket of paint and stir it, then stop, the fluid swirls around for a bit, slowing down all the while, because of FRICTION ("viscous effects") which turns the bulk flow of the paint into random molecular motion of the paint - heat. So if you stir a fluid, ultimately you heat it up. The reason a river doesn't just stop flowing and stagnate is because gravitational potential energy is constantly being converted to kinetic energy of the water flow, at a rate at least as high as the rate at which viscosity is turning the flow kinetic energy into heat. If that isn't true what you have is - a lake!

The Winter's Tale.

An Anarchist.