The European Physical Journal H最新文献

Max Planck is widely recognised for founding quantum theory. In his 1900 seminal work on black-body radiation, he also provided a numerical estimation of the elementary charge. This result, however, was embedded within his broader theoretical development and was not presented as a primary result, so that his contemporaries likely approached it with caution. Planck himself acknowledged that the theoretical basis that led to this estimate was fragile and explicitly noted that further experimental work was needed to confirm it. Remarkably, despite these limitations, his estimate closely matched values later confirmed by precise experiments. In this study, we examine how Planck’s contemporaries received and cited this estimate. We first situate his work within the scientific context of black-body radiation, then we analyse primary literature from 1901 to 1921, covering journals from Europe and the USA, to trace patterns of citation and engagement with Planck’s elementary charge estimate. Finally, a statistical bibliometric analysis quantifies these trends, revealing the visibility and impact of Planck’s work across different journals, national contexts, and scientific communities.

In Italy, in the decades surrounding Italian Unification—especially in the early years of the Kingdom of Italy—figures such as Pietro Blaserna and Carlo Matteucci commented critically on the state of the physical sciences, addressing institutional and pedagogical arrangements as much as research practices. At the same time, an alternative mode of knowledge production was emerging: an “epistemology of the province”—an analytical and historiographical category for forms of scientific research and experimental practice that were locally rooted yet sustained by supra-local circuits of communication and validation. This article examines such a provincial epistemic configuration through the work of Alessandro Serpieri (1823–1885), a scientist whose career at the University of Urbino spanned thirty-seven years. The analysis centres on three paradigmatic case studies: the first Italian replication of Foucault’s pendulum (30 March 1851); pioneering research into duplex telegraphy (1854–1855); and investigations of the first Bell telephones in Italy (1877–1878). These episodes collectively demonstrate how Serpieri’s locally grounded practice remained consistently engaged with the most advanced international technological debates. Across these episodes, Serpieri’s trajectory moves from mechanical and astronomical phenomena to electrotechnical questions and culminates in his study of the telephone, which foregrounds the listener as an active component in the device’s operation. He argued that much of the apparatus’s effectiveness in transmitting sound should instead be attributed to the listener’s interpretative capacity. This claim invites a retrospective comparison with later themes in cybernetics and the cognitive sciences, while remaining grounded in Serpieri’s nineteenth-century vocabulary of perception, judgement, and interpretation. Serpieri’s work thus encourages us to read provincial science not as a peripheral appendage, but as a productive epistemic environment, capable of transforming marginal constraints into methodological opportunities and of challenging centre–periphery hierarchies in the production of original knowledge.

Between 1933 and 1937, the treatment of relativistic spin-(nicefrac {1}{2}) particles, initially rooted in hole theory, evolved into the modern framework of quantum field theory. This paper reconstructs the crucial stages of that transition by examining the formal and physical progress of the numerous authors who shaped the field’s modern formalism. This historical study traces the development of fermionic field theory in full, beginning with the foundational work of the 1920s, focussing on the results of the 1930s, and concluding with the influential synthesis of Wolfgang Pauli in 1941, the content of which has shaped the subsequent tradition. Within this framework, particular emphasis is given to Ettore Majorana’s 1937 quantisation procedure and argument for anti-commuting fermionic quantum fields. This study demonstrates that Majorana’s work was not merely a technical variant, but the definitive rejection of the concept of negative energy solutions, whose conceptual clarity and educational value remain vital today.

Gupta was among the first to attempt the quantization of Einstein’s nonlinear theory of gravity. He had an independent program to quantize gravity in a manner akin to electromagnetism, which spanned at least two decades. He adopted the flat-space views of Rosen and Papapetrou and built his theory around these ideas. Although he was well known for his work in quantum electrodynamics, little is known about his work in quantum gravity. For that reason, in this paper, we try to present a historical overview of his research program.

Two striking, physically wrong assumptions are asserted in the 1940 Frisch-Peierls' Memorandum: The Memorandum ignores the known large scattering cross section while inventing a hypothetical fission cross section that is twenty times larger than the known fission cross section in 1940. The point of this paper is to show how Frisch used Peierls' approximate solution to his nonstandard chain reaction–diffusion equation along with the two wrong cross-section assumptions to make the Memorandum's famous critical radius prediction. Frisch's two 'vastly optimistic' cross sections were essential for getting the neutron multiplication number ν ≈ 2.3 (the average number of neutrons per fission event) into the right place in Peierls' partial differential equation. If we simply translate Frisch's assumptions as stated in the 1940 Memorandum directly into equations, then the prediction that R = 0.8 L with a correspondingly too small mean free path L = 2.6 m falls out from Peierls' approximate solution of his partial differential equation. Under these assumptions, the mean free path is identical with the fission mean free path. Summarizing, following the shortest path that Frisch could have taken leads us directly to R = 0.8 L and the end of the mystery of how he could have predicted the tiny critical radius.

In this work I reopen the measurement problem taking into account Steven French’s recent book on the possibility of a phenomenological approach to quantum mechanics, taking into account the interpretation of London and Bauer, whom French considers the precursors of this approach. We will see to what extent French can be right in this statement, through a historical review in which the problem of measurement is contextualized. In this reopening we will have the opportunity to revisit some of the most notable contributions to this problem, such as Bohr, Born or von Neumann, among others. Current perspectives will also be added, which will help us to understand the state of the art.

This paper offers a historical overview of the origins and enduring significance of gravitational particle creation, a groundbreaking discovery first formulated in Leonard Parker’s 1966 doctoral thesis at Harvard University. By tracing the context in which Parker developed this idea and examining its subsequent influence, the paper highlights how the concept of gravitational particle creation advanced the study of quantum field theory in curved spacetime and profoundly shaped modern cosmology, as well as the quantum theory of black holes.

The aim of this paper is to retrace the path that led the young Enrico Fermi to write his paper on the statistics of an ideal monatomic gas. This discovery originated in his interest, which he had shown since his formative years, in the absolute entropy constant and in the problems he highlighted in Sommerfeld’s quantization in the case of identical particle systems. The fundamental step taken by Fermi in writing his work on statistics was to apply the Exclusion Principle, formulated for electrons in an atom and which could therefore have been a pure effect due to dynamics, to a system of non-interacting particles.

In this article, I trace the early historical developments that ultimately led to the creation of the atomic bomb. Even after the weapon’s completion, a number of scientists continued to argue that nuclear armaments were indispensable for maintaining the global balance of political power [1]. This study focuses on several scientists who confronted profound moral dilemmas concerning the bomb’s use against Japan. Some openly opposed its deployment, others sought to warn a Japanese scientist in the hope of averting further devastation, and still, others expressed deep remorse in its aftermath. In addition, the experience of an individual directly affected by the bombing is discussed. By examining these episodes, this article aims to contribute to the ongoing discourse on how scientific research should be guided by ethical principles in the future.

Hilbert-space techniques are widely used not only for quantum theory, but also for classical physics. Two important examples are the Koopman-von Neumann (KvN) formulation and the method of “classical” wave functions. As this paper explains, these two approaches are conceptually distinct. In particular, the method of classical wave functions was not due to Bernard Koopman and John von Neumann, but was developed independently by a number of later researchers, perhaps first by Mario Schönberg, with key contributions from Angelo Loinger, Giacomo Della Riccia, Norbert Wiener, and E. C. George Sudarshan. The primary goals of this paper are to explain these two approaches, describe the relevant history in detail, and give credit where credit is due.