The publication of the first edition of Physics in 1960 launched the modern era of physics textbooks. It was a new paradigm then and, after 40 years, it continues to be the dominant model for all texts. The big change in the market has been a shift to a lower level, more accessible version of the model. Fundamentals of Physics is a good example of this shift. In spite of this change, there continues to be a demand for the original version and, indeed, we are seeing a renewed interest in Physics as demographic changes have led to greater numbers of well--prepared students entering university. Physics is the only book available for academics looking to teach a more demanding course.