The physics of pawnbroking

I am ashamed to admit that I boycotted my undergraduate quantum mechanics lectures on the grounds that I did not consider the lecturer to be rigorous enough. I soon realised the error of my ways, but opening the front cover of Modern Physics , old prejudices briefly returned on seeing the explanation of symbols such as =, <<, >. In the corresponding slot Nonclassical Physics already lists moments of Gaussian integrals.

Both books cover large parts of the theoretical curriculum for an undergraduate physics degree in the UK, leaving out classical mechanics, thermodynamics and electromagnetic fields. With the exception of astrophysics, both cover the same range and progression of topics. In some subjects, deeper supplementary texts might be required. Overall, the material is more densely packed than, say, Fundamentals of Physics Extended by David Halliday, Robert Resnick and Jearl Walker.

Diagrams, summaries, exercises (full answers available separately) and appendices (who did not win the physics Nobel prize in 1942?) are provided in both texts. Nonclassical Physics perhaps provides more solid mathematical explanations but uses boxes to highlight key points or equations. Modern Physics includes "real-world" applications such as neutron activation analysis (art restoration), tomography (medicine) and gold-chain analysis (pawnbroking?). A nice touch is the faces it puts to the names of more than just Einstein, including a tennis-injured Fermi. Which of the two texts (if either) might be recommended will come down to personal or departmental preference. The principal difference is the web-based aspects of Modern Physics.

Two types of icons punctuate Modern Physics . The first indicates that a section contains "material of high interest to students". It is perhaps slightly worrying that "calibrating the spacetime axes" is apparently deemed more interesting than "safety issues of fission reactors" to next-generation physicists.

The second type of icon indicates "more" sections, which are only available on the publisher's website. On receiving my review copy I eagerly accessed the website, and found well-presented potential handouts, some covering topics whose explanation would be difficult to reproduce satisfactorily under lecture conditions. However, it is not clear which scientific or educational criteria determine whether a subject is available exclusively on the website. Some of the web topics are background material, but others, such as the nuclear semi-empirical mass formula or the chapter on astrophysics, can only be studied online.

A web-integrated textbook is potentially an exciting innovation in teaching. It could aid key skills by enhancing physics students' assertiveness as they compete for time on university computers with those plagiarising their next essays. More seriously, a web-based book provides opportunities for deeper study by more able students and alternative approaches for weaker ones. However, as with all computer-aided learning, unless properly integrated into the assessment of the course, will the time servers really bother? A publisher can make easy and cheap changes to the website, thereby stimulating more sales of new paper editions. For new undergraduates this is not a problem, but one hopes that older material would still be available for existing students with the previous edition. On the other hand, is a freely available website likely to be supported without cluttering it with banners to the extent that it becomes unusable?

Eager to follow up the story of an outdoor encounter between Mrs Bohr and Pauli, I took the advice of the authors "so you, too, won't be unhappy", and tried to access the site again. The web may be a product of modern physics, but experimentally it obeys a wholly different set of fundamental laws: "Microsoft OLE DB Provider ... permission denied."

Chris Howls is lecturer in applied mathematics, University of Southampton.