In 1911 the Wilson cloud chamber opened new possibilities for physics pedagogy. The instrument, which visualized particles’ tracks as trails of condensed vapour, was adopted by physicists to pursue frontier research on the Compton effect, the positron and the transmutation of atomic nuclei. But as the present paper will show, Wilson's instrument did not just open up new research opportunities, but the possibility of developing a different kind of teaching. Equipped with a powerful visualization tool, some physicists–teachers employed Wilson's instrument (...) to introduce their students to a wide range of phenomena and concepts, ranging from the behaviour of clouds to Einstein's photon, the wave–particle duality and the understanding of the nucleus. This paper uses the notes, books and prototypes of these pioneering physicists–teachers to compose a pedagogical history of the Wilson cloud chamber, documenting an episode of immense ingenuity, creativity and scientific imagination. (shrink)

The focus of this paper is one of James Prescott Joule’s scientific contributions: the laws of heat production by electric currents in conductors. In 1841, the 22 years old Joule published a paper with the title “On the heat evolved by metallic conductors of electricity, and in the cells of a battery during electrolysis” where he presented an experimental study of that phenomenon and proposed two laws that were allegedly supported by his trials. On closer inspection, both his laboratory work (...) and his inferences can be challenged. The emphasis of this article is an attempt to understand Joule’s experimental undertaking, its highpoints and shortcomings, by a detailed analysis of this specific episode and by studying the precedents of his work and subsequent advancements. It is possible to point out several serious deficiencies of that investigation, and Joule’s contemporaries, such as Edmond Becquerel and Heinrich Lenz, did criticize some of his flaws and undertook new experiments to provide a sound basis for those laws. Besides providing a historical examination of that specific episode, this article uses this case study to tackle some features of the nature of science that may contribute to scientific education. (shrink)

This article is a contribution to the history of the Geiger-Müller counter, based on the replication method. Along with a historical analysis of the Geiger-Müller counter I present and discuss my experience with replicas of early counters from 1928. The explicit and tacit knowledge that was gained during my construction und the experimentation process allows a different view of the development process in 1928. Against this background, I discuss Walter Müller’s role in the development and the significance of experimental work (...) in Geiger’s laboratory by illustrating the status of data gained from indirect electrical measurements in the field of early radioactivity research. All things considered it was not the instrument itself, but Geiger’s influence and status that affected its establishment in the scientific community in an authoritative way. (shrink)