'Let the stars shine in peace!' Niels Bohr and stellar energy, 1929-1934.

Faced with various anomalies related to nuclear physics in particular, in 1929 Niels Bohr suggested that energy might not be conserved in the atomic nucleus and the processes involving it. By this radical proposal he hoped not only to get rid of the anomalies but also saw a possibility to explain a puzzle in astrophysics, namely the energy generated by stars. Bohr repeated his suggestion of stellar energy arising ex nihilo on several occasions but without ever going into detail. In fact, it is not very clear what he meant or how seriously he took the stellar energy hypothesis. This paper relates Bohr's comments to the period's attempts to find a mechanism for stellar energy and also to the role played by astrophysics at the Copenhagen institute. Moreover, it looks at how Bohr's hypothesis was received not only by physicists but also by astronomers. In this regard the disciplinary status of astrophysics and its contemporary relation to the new quantum mechanics is of relevance. It turns out that, with very few exceptions, the hypothesis was met with silence by astronomers and astrophysicists concerned with the problem of stellar energy production. And yet, for a brief period of time it did have an impact on how physicists thought about the interior of the stars.

Contributions from Women to the Radiation Sciences: A Brief History.

Contributions from men to radiation science are well known, particularly the early contributions from such luminaries as William Roentgen, James Chadwick, Niels Bohr, Robert Oppenheimer, and the like. Although not ignored per se, beyond Marie Curie and Lise Meitner, the contributions of female nuclear scientists are not as widely recognized. This paper provides a concise historical summary of contributions to radiation science from the discovery of radiation through the current status of international leadership within the radiation protection community. Beyond lead scientists and academics, this paper also considers support personnel as well as the role women have played in the advancement of radiation epidemiology.

Discovery of rhenium and masurium (technetium) by Ida Noddack-Tacke and Walter Noddack. Forgotten heroes of nuclear medicine.

The history of the early identification of elements and their designation to the Mendeleev Table of the Elements was an important chapter in German science in which Ida (1896-1978) and Walter (1893-1960) Noddack played an important role in the first identification of rhenium (element 75, 1925) and technetium (element 43, 1933). In 1934 Ida Noddack was also the first to predict fission of uranium into smaller atoms. Although the Noddacks did not for some time later receive the recognition for the first identification of technetium-99m, their efforts have appropriately more recently been recognized. The discoveries of these early pioneers are even more astounding in light of the limited technologies and resources which were available during this period. The Noddack discoveries of elements 43 and 75 are related to the subsequent use of rhenium-188 (beta/gamma emitter) and technetium-99m (gamma emitter) in nuclear medicine. In particular, the theranostic relationship between these two generator-derived radioisotopes has been demonstrated and offers new opportunities in the current era of personalized medicine.

Across borders: science and technology during the Cold War. An introduction

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Clouds, airplanes, trucks and people: carrying radioisotopes to and across Mexico

The aim of this paper is to describe the early stages of Mexican nuclearization that took place in contact with radioisotopes. This history requires a multilayered narrative with an emphasis in North-South asymmetric relations, and in the value of education and training in the creation of international asymmetrical networks. Radioisotopes were involved in exchanges with the United States since the late 1940s, but also with Canada. We also describe the context of implementation of Eisenhower´s Atoms for Peace initiative in Mexico that opened the door to training programs at both the Comisión Nacional de Energía Nuclear and the Universidad Nacional Autónoma de México. Radioisotopes became the best example of the peaceful applications of atomic energy, and as such they fitted the Mexican nuclearization process that was and still is defined by its commitment to pacifism. In 1955 Mexico became one of the 16 members of the atomic fallout network established by the United Nations. As part of this network, the first generation of Mexican (women) radio-chemists was trained. By the end of the 1960s, radioisotopes and biological markers were being produced in a research reactor, prepared and distributed by the CNEN within Mexico. We end up this paper with a brief reflection on North-South nuclear exchanges and the particularities of the Mexican case (AU)

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A brief history of Lord Rutherford's radium.

In this paper I give a brief summary of what is known about the acquisition, use and fate of the radium sources that were in the possession of Lord Rutherford during his lifetime. The account is written in two parts, corresponding to the periods from the discovery of radium in 1898 until his death in 1937 and then from 1937 until recent times. The history of Rutherford's radium closely shadows the history of radioactivity, the evolution of nuclear physics, the race for the bomb, and the development of the nuclear industry.

[Carl Friedrich von Weizsäcker (1912-2007): scientist and citizen]. / Carl Friedrich von Weizsäcker (1912-2007): Wissenschaftler und Citoyen.

This contribution provides an introductory overview of the life and work of Carl Friedrich von Weizsäcker for the present volume. It presents him as a prominent scholar of the twentieth century. This pupil of Werner Heisenberg made fundamental contributions to physics, specifically, nuclear physics, and after World War II was able to excel as a highly acknowledged philosopher of science and pioneer in twentieth-century conflict and peace research. Beyond science, politics and religion also counted among the defining influences of Weizsäcker's life, which also molded him into civic leadership. This aspect is treated particularly in the second and central part of this article, which discusses and closely documents his membership in the Leopoldina and his engagement elsewhere, particularly in the sphere of East German church activities.

[Weizsäcker's cosmogony, Farm Hall and the origin of modern turbulence theory]. / Weizsäckers Kosmogonie, Farm Hall und die Entstehung der modernen Turbulenztheorie.

The modem statistical theory of turbulence was originated by Andrey Nikolaevich Kolmogorov (1903-1987), Lars Onsager (1903-1976), Ludwig Prandtl (1875-1953), Werner Heisenberg (1901-1976) und Carl Friedrich von Weizsäcker (1912-2007). With the exception of Kolmogorovs theory which was published in 1941 but became widely known only after the war, these contributions emerged largely independently from another in a "remarkable series of coincidences" (Batchelor 1946). Heisenberg and Weizäscker developed their theories during their detention at Farm Hall. Their work was motivated by von Weizsäcker's interest in astrophysics. Weizsäcker aimed at an understanding of the role of turbulence for the motion of interstellar matter for his theory about the origin of the planetary system which he had published in 1943. Weizsäcker's work on cosmogony and turbulence illustrates an early interaction between the disciplines of astronomy and fluid mechanics that became characteristic for astrophysics in the second half of the twentieth century.

[Weizsäcker, Bethe and the Nobel Prize]. / Weizsäcker, Bethe und der Nobelpreis.

For his work on nuclear physics Carl Friedrich von Weizsäcker was twice nominated for the Nobel Prize in physics. Bethe had worked on the energy production in stars at about the same time as Weizsäcker but independently from him. The Nobel Committee valued the structural depth of BETHE'S work more than Weizsäcker's temporal priority because Bethe had described the nuclear reactions quantitatively and had shown a much deeper understanding of the nuclear processes in the centre of stars whereas Weizsäcker had worked more qualitatively. There are no reasons to believe that political resentments towards Weizsäcker played any significant role in awarding of the Nobel Prize in Physics in 1967 only to Bethe. The lives and works of Weizsäcker and Bethe show some remarkable parallels, ranging from calculating the binding energy in nuclei to the energy production in sun-like and massive stars to peace- and disarmament initiatives.

["Living with the bomb" - Carl Friedrich von Weizsäcker's path from physics to politics]. / "Mit der Bombe leben"--Carl Friedrich von Weizsäckers Weg von der Physik zur Politik.

Carl Friedrich von Weizsäcker spanned a spectrum from physics to politics, with philosophy in-between. This chapter surveys the most controversial part of his career, including his work on nuclear weapons and participation in cultural propaganda during the Second World War, his subsequent active political engagement during the postwar Federal German Republic, in particular the role of nuclear weapons, and his participation in myths surrounding Hitler's Bomb".

[Living with responsibility: Max Born and Carl Friedrich von Weizsäcker as philosophers with distance]. / Mit der Verantwortung leben: Max Born und Carl Friedrich von Weizsäcker als Denker mit Distanz.

Both Carl Friedrich von Weizsäcker und Max Born belong to the most active scientists, which have raised their voice for peace in the 1950s. While Born, senior to Weizsäcker by one generation, engaged in peace movements at an early stage, which was also due to his emigration, and was a driving force for the Einstein-Russell memorandum, Weizsäcker entered the stage essentially with the Göttingen declaration but quickly dominated the discourse. The comparison of their different engagements for peace sheds new light on Weizsäcker. Unlike the German emigrant with a British passport, who was mainly influenced by EInstein and Russell as well as some socialist thoughts he had encountered at an early age, the son of a noble diplomat and the physicist, who was saved from military duties because of his work in the German wartime nuclear project, had quite a different perspective on the postwar atomic threat. The relation of Born and Weizsäcker remained marked by a certain distance even when both took up very similar roles of 'public scientists' active for peace, be it as delegates at Pugwash conferences, on the air, or as speakers in the Frankfurt Paulskirche.

[Carl Friedrich von Weizsäcker and Werner Heisenberg]. / Carl Friedrich von Weizsäcker und Werner Heisenberg.

The 50-year relationship between Weizsäcker and Heisenberg spanned the highpoints of discovery and dictatorship during the 1930s, extended into the war-time uranium project, the post-war controversy over that project, debates over West German nuclear policy, and the philosophical implications of modern physics. This paper explores the interaction between these two leading figures during that difficult and significant half-century.