At first almost ignored and unread, Sadi Carnot's analysis of heat engines--published 150 years ago--contained ideas and methods that were developed later by Clausius and Thomson. Carnot's ideas and their influence on later science are discussed. (Author/RH)

Discusses the origin of de Broglie's concept and its influences on his contemporaries, notably on Einstein, Schrodinger, Elsasser, Davisson, and Thomson. Indicates that the theory served not only as the starting point of quantum mechanics, but also opened new experimental possibilities. Historical inaccuracies are corrected with new material…