Einstein in Portugal: Eddington’s expedition to Principe and the reactions of Portuguese astronomers (1917–25)

Among various case studies addressing the reception of relativity, very few deal with Portugal at either the international or the national level. The national literature on the topic has mainly concentrated on the reactions to relativity of the Portuguese mathematical community. The absence of Portuguese astronomers alongside Eddington during the 1919 expedition to Principe, then a Portuguese island, has been implicitly equated with the astronomical community’s lack of interest in the event. In reception studies dealing with general relativity, analysis has tended to focus on the physics and mathematics communities, less on the astronomers. Given that relativity was born at the interface of physics, mathematics and astronomy, reactions of members of these scientific communities depended on differences in shared traditions, values, problems and expectations, as well as on individual practitioners’ idiosyncrasies. This paper addresses the contributions of the overlooked Portuguese astronomical community, evaluates the actions and reactions of its members to the expedition and assesses their role in the process of appropriation of relativity.