This book is intended as a contribution to cognitive psychology and educational practice. Nevertheless, it would not have been written had it not been for a simple fact of modern life, that many students experience school physics as extremely unpleasant. Indeed, many students regard school physics as a painful ordeal whose only saving grace is that it can be quickly jettisoned in favour of the humanities or the biological sciences. Thus, even amongst A-level candidates, who are themselves a selective sample, only about one-sixth of students are currently enrolled in physics.1 This rejection of school physics led to the book because of the discussion about what lies behind it, discussion in other words of why physics proves such a nightmare that so many students wish to abandon it at the first opportunity. The discussion has been wide-ranging for there is considerable anxiety about our nation’s competitiveness when such a central science is being shunned, and over the years a range of proposals have been made. One favourite is poor teaching. It is argued that when physicists are so rare and so valuable, the good and inspirational ones are unlikely to be attracted to a low-paid profession like teaching. Another is to call on the nature of physics. It is said to be too mathematical or, with phrases like ‘a massless rope strung over a frictionless pulley’, too abstract.