Cambridge University Press are to be congratulated on making these two excellent and thought provoking lectures available Elementary Particles and the Laws of Physics is a book that all physicists will be pleased to have on their shelves, and one that will surely stimulate aspiring theoretical physicists Tony Hey, New Scientist Richard Feyman and Steven Weinberg are both outstanding lecturers and expositions All those interested in the development of modern physics will find this a fascinating book Physics Briefs Most enjoyable and stimulating reading highly recommended A G Klein, Australian Physicist Recommended reading for anyone interested in Dirac s work B R Parker, Choice The text of theDirac Memorial Lectures, long available as a slim hardback, is now available in paperback Over a decade later, the messages in these lectures remain fresh International Journal of High Energy Physics readers of this booklet will not be disappointed Hubert Goenner, General Relativity and GravitationPerhaps the two most important conceptual breakthroughs in twentieth century physics are relativity and quantum mechanics Developing a theory that combines the two seamlessly is a difficult and ongoing challenge This accessible book contains intriguing explorations of this theme by the distinguished physicists Richard Feynman and Steven Weinberg Richard Feynman s contribution examines the nature of antiparticles, and in particular the relationship between quantum spin and statistics In his essay, Steven Weinberg speculates on how Einstein s theory of gravitation might be reconciled with quantum theory in the final laws of physics Both these Nobel laureates have made huge contributions to fundamental research in physics, as well as to the popularization of science Anyone interested in the development of modern physics will find this a fascinating book