Louis de Broglie’s wave-particle duality : from textbooks’ blackboxes to a chain of reference presentation

Abstract

We discuss the proposition of wave-particle duality made by Louis de Broglie in the period of 1922-1924 as well as the narratives of undergraduate Physics textbooks that introduce this topic. After a brief discussion on the nature of scientific reality, we point out the main theories, assumptions and techniques adopted by de Broglie to achieve the relation between momentum and wavelength. We use these elements as analytical categories, observing which of them are still present in four popular undergraduate introductory textbooks. Our results show that none of the textbooks used de Broglie’s original strategy (mathematical derivation), treating his ideas as postulates. Moreover, we show that only few elements of de Broglie’s original presentation are still commented by textbooks, which treat de Broglie’s ideas as purely speculative, reinforcing the “genius myth”. In the sequence, we propose a didactic alternative, which we call a “chain of reference presentation”. In this strategy, we highlight that all scientific knowledge is supported by previous theories and it works as the ground of future scientific improvements. With this perspective, we perform a didactic derivation of de Broglie’s momentum-wavelength relation (based on the original papers and on the specialized literature) and we introduce empirical and theoretical works that may be studied from it.