So I thought it was now… let me calculate, it was 15 or so years getting on that way, certainly more than a decade, from… yes, it must have been 15 years since I left Australia, and my Masters work on copper oxide was, in a way, a dim memory. I hadn’t been keeping up with that sort of literature, so I thought I’d better find out what the current scenes in solid state nonstoichiometry were, and whether Mössbauer could solve any of these problems.

And remembering an old adage which JS Anderson told me as a graduate student, ‘Norman, if you want to learn a subject, write a book on it’. Well, I’d just done that with Mössbauer Spectroscopy, I suppose, and I thought if I’m going to find out what is current in the solid state field, I’d better write a book on it. And the way to do that was to take sabbatical leave and go to a university in America and see what would come of that. So I did. I went to Michigan State University, and I wrote a book called Ionic Crystals, Lattice Defects, and Nonstoichiometry.