Abstract The recent discovery of new documentation concerning Bruno Benedetto Rossi’s life and career provides new information about Italian and European cosmic-ray physics during the 1930s. The present article analyses part of this new material, focusing on documents that allow a thorough reconstruction of Rossi’s scientific expedition to Eritrea, which was a colony of fascist Italy at the time. We examine Rossi’s scientific practices step-by-step and highlight the institutional and political endeavors that allowed the expedition to take place. Discussing the fascist-colonial context of the expedition provides a key tool to understand the facts reported completely. We also consider the interesting yet forgotten scientific collaboration Rossi had on that occasion with Arthur H. Compton.

Abstract This article explores the entanglement of scientific collaboration and Cold War geopolitics through the lens of four major particle accelerator complexes: CERN (Europe), JINR/Dubna and IHEP/Serpukhov (Soviet Union), and NAL/Fermilab (United States). Despite their scientific significance, the origins and evolution of their exchange programs remain understudied. Moving beyond the conventional East-West binary, we adopt a multipolar framework to analyze how these four institutions forged enduring collaborations. From the first decade of the Cold War through the 1970s détente, bilateral agreements enabled the growing flow of personnel, equipment, and knowledge between CERN, JINR, Serpukhov, and Fermilab, thereby crossing national borders and ideological divides. These institutions operated strategically within the contested arena of the Cold War constellation, where competition for scientific leadership paradoxically fostered collaboration. Although plans for a joint global accelerator remained unrealized, our analysis highlights how international collaboration evolved into a nuanced, multilevel, and multipolar interplay—one that was shaped as much by scientific ambition as by persistent asymmetries and power dynamics.

Abstract The Italian physicist Macedonio Melloni (1798–1854), best known for his work on “radiant heat,” devoted the last years of his life to the field of electricity and magnetism. As part of his research, he designed and built an innovative induction electrometer shortly before his death. This device was presented to the Royal Academy of Sciences in Naples a few days after the scientist’s death. One of the existing examples of this device is kept in the Physics Museum of the Museum Centre of Natural and Physical Sciences of the University of Naples Federico II and bears the inscription “ Ultima scoverta del Cav. Melloni ” (last discovery of Cavalier Melloni) on the dial. The present work aims on the one hand to provide a detailed analysis of the construction and functioning of this electrometer and, on the other hand, to place it in the panorama of existing and later electroscopes. An attempt is also made to reconstruct the history of the other surviving examples of Melloni’s electroscope.

Abstract For decades, research on the Standard Model dominated the field of elementary particle physics and searches for new physics beyond it were driven by the predictions of particular models, among them supersymmetry. These predictions have not borne fruit at the Large Hadron Collider, and as such physicists are increasingly turning to experiment for guidance. In this paper, we provide a philosophical analysis of the change, diagnosing it as a shift in consensus on where the field of particle physics expects the most progress and by defining general criteria whether a field is driven by theory or experiment. We base our analysis of the history of particle physics on programmatic documents issued by the large experiments, summary reports at the annual conferences assembling nearly all particle physicists, and on expert interviews and questionnaires conducted by us over the past decade.

Abstract The Schwarzschild solution was the first exact solution to Einstein’s 1915 field equations, found by Karl Schwarzschild as early as 1916. And yet, physicists, mathematicians and philosophers have struggled for decades with the interpretation of the Schwarzschild solution and the two singularities appearing in it when it is written in polar coordinates. This article distinguishes between eight different ways in which the two singularities have been interpreted between 1916 and the late 1960s, when Penrose’s first singularity theorem shed new and lasting light on the interpretation of the Schwarzschild solution.