Sunday, September 30, 2012

Teachers Write an Open Textbook In a Weekend Hackathon

I can appreciate this. Having just completed a physics masters, I am well acquainted with trying to find textbooks on various things, often referring to the Big Names In Physics Textbooks - that is Landau/Lifshitz, Griffiths, Hecht, Goldstein, Sakurai and the list goes on. The problem is that very few books are written to the levels that students need them.

Introductory undergraduate texts are often superficial enough for a first pass, but quickly become doorstops (e.g. Young and Freedman). Personally I still found them useful for occasional things, but by and large we forgot about them. When you graduate things become more tricky and you resort to reading peer publications and textbooks that fit your niche. This is tricky, but hey, it's research and you live with it. The problem is in between, those three or four years of undergrad where you need excellent concise explanations of, in reality, very complicated phenomena. Most of the time that simply doesn't exist.

After four years of my degree I hit problems. I understood what was taught in the lectures, but I had problems applying the information to other things. Why? Because I found myself asking whether something was possible or not. This was especially apparent in General Relativity with tensor calculus, I was hesitant to work through equations because I wasn't sure whether I could do operation X or if such and such was valid. It's that horrible feeling of knowing enough about a topic to understand that what you're about to do is wrong, but not enough to know the solution.

Let's take quantum mechanics as an example. The textbooks almost uniformly start in the same way, a quick overview of the observed phenomena, some stuff on wave-particle duality and a headfirst dive into the Schr?dinger Equation followed by uses thereof. By the time you get to higher level QM and things like bra-ket notation is introduced, people get confused. They get even more confused when analogies to vectors start being bandied around and when operators come into the fray it gets worse. Why? Because they started the wrong way. Going in the other direction, the big well known books in QM are strictly graduate and often the people recommending them really have no idea what they're talking about. There simply aren't that many geniuses in most colleges/universities. Realistically 95% of students need simple, hand-holdy books with a lot of solid grounding.

There is only one textbook I've found at an undergraduate level that remedies this for QM, and that's Shankar. Whereas most books begin with historical waffle, Shankar immediately dives in with mathematics. Quantum mechanics barely gets mentioned until the third chapter. Why is this? Because it lets you get your head around the idea of a vector "not being a stick with an arrow" as he puts it. Once you understand that a vector is simply a mathematical object that obeys a set of rules and that position vectors happen to obey them also, things get easier. The second chapter is still no quantum and in fact deals with Hamiltonian mechanics, I know of no other book that does this in quite this way. As a result, by the time you get to introducing quantum effects, it is easy to explain the Schr?dinger equation in terms of abstract maths and solving problems becomes more straight forward. In fact, you realise that you learned about operator notation, eigenvector/value/functions before you even learned about the wavefunction and it's simply a matter of applying your knowledge.

The rest of the book is fairly self explanatory, all the usual topics are covered in a decent amount of detail although there is no field theory. But that's not the point. The point is that the reader is given a rigorous mathematical explanation of the physics before the physics is taught. As a result, the physics becomes almost trivial and you can understand why things connect the way they do.

Extend this to the rest of textbooks and you have your problem. Authors need to step into the students' shoes a

Source: http://rss.slashdot.org/~r/Slashdot/slashdotScience/~3/0vZ_1YRYvm4/teachers-write-an-open-textbook-in-a-weekend-hackathon

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