The Ether Concept from Spanish Physics Textbooks (1840–1950)

Abstract The presence of the ether concept in the contents of 73 Spanish physics textbooks (secondary and first course university level) published in the period 1840–1950 is studied. The textbooks are a specially interesting learning tool in the Spanish society of this period, due to the rural character of the country, the capacity of the textbooks for frequent and repeated use as well as for dissemination over the entire state. Particularly, the content about heat, light and electricity is investigated. Whether the concept of ether appears in the general principles of the textbooks or not is also studied. Moreover, the work considers the evolution of the concept of ether by decades, showing different examples of how the ether was used to explain different physics phenomena. Furthermore, the social and historical context in which the textbooks were developed is discussed in detail. Outstanding amongst the different conclusions that are drawn is the disappearance of the concept of the ether during the third and fourth decades of the twentieth century.