It is now nearly a decade since the first edition of Elements of Modern X-ray Physics first appeared. Given the immense level of interest in x-rays and their exploitation, it is not surprising that there have been tremendous developments in this field in the intervening years. In this book the basics of x-ray physics, as well as the completely new opportunities offered by synchrotron radiation, are viewed from a modern perspective. The style of the book is to develop the basic physical principles without obscuring them with excessive mathematics. The second edition differs substantially from the first edition, with approximately 30% new material, including:? A new chapter on non-crystalline diffraction - designed to appeal to the large community who study the structure of liquids, glasses, and most importantly polymers and bio-molecules.