Emergence of a techno-legal specialty: Animal tests to assess chemical safety in the UK, 1945–1960

It has been suggested that knowledge domains which emerge within regulatory science represent a compromise between technical knowledge and policy priorities. This article investigates the claim through consideration of the emergence of animal tests to evaluate chemical safety in the UK between 1945 and 1960. During this period there was a proliferation of new chemical-based innovations in consumer products. The situation gave rise to concerns about the potential impact on public health. Solutions required development of a knowledge domain that would fulfil policy requirements, outside the remit of academic science. Lack of consensus in the scientific field gave rise to debate over the best means to collect accurate data. This resulted in emergence of the new specialty of safety testing, in response to political and industrial needs. The socio-political context of this case illustrates the impact that organisational setting can have on shaping knowledge claims.     

The best of many worlds,or, is quantum decoherence the manifestation of a disposition?

In this paper I investigate whether the phenomenon of quantum decoherence, the vanishing of interference and detectable entanglement on quantum systems in virtue of interactions with the environment, can be understood as the manifestation of a disposition. I will highlight the advantages of this approach as a realist interpretation of the quantum formalism, and demonstrate how such an approach can benefit from advances in the metaphysics of dispositions. I will also confront some commonalities with and differences to the many worlds interpretation, and address the difficulties induced by quantum non-locality. I conclude that there are ways to deal with these issues and that the proposal hence is an avenue worth pursuing.     

The origin of the Everettian heresy

In 1956, Hugh Everett, then a PhD student at Princeton, proposed his “relative state” formulation of quantum mechanics. John Wheeler, who was Everett's advisor, recognized the originality and importance of such a proposal, but he denied that its non-conventional approach to measurement questioned the orthodox view. Indeed, Wheeler made serious efforts to obtain the blessing of Niels Bohr for Everett's ideas. These efforts gave rise to a lively debate with the Copenhagen group, the existence and content of which have been only recently disclosed by the discovery of unpublished documents. The analysis of such documents opens a window on the conceptual background of Everett's proposal, and illuminates at the same time some crucial aspects of the Copenhagen view of the measurement problem. Also, it provides an original insight into the interplay between philosophical and social factors which underlay the postwar controversies on the interpretation of quantum mechanics.     

Formal and physical equivalence in two cases in contemporary quantum physics

The application of analytic continuation in quantum field theory (QFT) is juxtaposed to T-duality and mirror symmetry in string theory. Analytic continuation—a mathematical transformation that takes the time variable t to negative imaginary time—it—was initially used as a mathematical technique for solving perturbative Feynman diagrams, and was subsequently the basis for the Euclidean approaches within mainstream QFT (e.g., Wilsonian renormalization group methods, lattice gauge theories) and the Euclidean field theory program for rigorously constructing non-perturbative models of interacting QFTs. A crucial difference between theories related by duality transformations and those related by analytic continuation is that the former are judged to be physically equivalent while the latter are regarded as physically inequivalent. There are other similarities between the two cases that make comparing and contrasting them a useful exercise for clarifying the type of argument that is needed to support the conclusion that dual theories are physically equivalent. In particular, T-duality and analytic continuation in QFT share the criterion for predictive equivalence that two theories agree on the complete set of expectation values and the mass spectra and the criterion for formal equivalence that there is a “translation manual” between the physically significant algebras of observables and sets of states in the two theories. The analytic continuation case study illustrates how predictive and formal equivalence are compatible with physical inequivalence, but not in the manner of standard underdetermination cases. Arguments for the physical equivalence of dual theories must cite considerations beyond predictive and formal equivalence. The analytic continuation case study is an instance of the strategy of developing a physical theory by extending the formal or mathematical equivalence with another physical theory as far as possible. That this strategy has resulted in developments in pure mathematics as well as theoretical physics is another feature that this case study has in common with dualities in string theory.     

Theoretical construction in physics – The role of Leibniz for Weyl's ‘Philosophie der Mathematik und Naturwissenschaft’

This paper aims at closing a gap in recent Weyl research by investigating the role played by Leibniz for the development and consolidation of Weyl's notion of theoretical (symbolic) construction. For Weyl, just as for Leibniz, mathematics was not simply an accompanying tool when doing physics—for him it meant the ability to engage in well-guided speculations about a general framework of reality and experience. The paper first introduces some of the background of Weyl's notion of theoretical construction and then discusses particular Leibnizian inheritances in Weyl's ‘Philosophie der Mathematik und Naturwissenschaft’, such as the general appreciation of the principles of sufficient reason and of continuity. Afterwards the paper focuses on three themes: first, Leibniz's primary quality phenomenalism, which according to Weyl marked the decisive step in realizing that physical qualities are never apprehended directly; second, the conceptual relation between continuity and freedom; and third, Leibniz's notion of ‘expression’, which allows for a certain type of (surrogative) reasoning by structural analogy and which gave rise to Weyl's optimism regarding the scope of theoretical construction.     

QED and the man who didn׳t make it: Sidney Dancoff and the infrared divergence

Sidney Dancoff׳s paper “On Radiative Corrections for Electron Scattering” is generally viewed in the secondary literature as a failed attempt to develop renormalized quantum electrodynamics (QED) a decade early, an attempt that failed because of a mistake that Dancoff made. I will discuss Dancoff׳s mistake and try to reconstruct why it occurred, by relating it to the usual practices of the quantum field theory of his time. I will also argue against the view that Dancoff was on the verge of developing renormalized QED and will highlight the conceptual divides that separate Dancoff׳s work from the QED of the late 1940s. I will finally discuss how the established view of Dancoff׳s paper came to be and how the reading of this specific anecdote relates to more general assessments of the conceptual advances of the late 1940s (covariant techniques, renormalization), in particular to their assessment as being conservative rather than revolutionary.     

Quantum jumps,superpositions, and the continuous evolution of quantum states

The apparent dichotomy between quantum jumps on the one hand, and continuous time evolution according to wave equations on the other hand, provided a challenge to Bohr's proposal of quantum jumps in atoms. Furthermore, Schrödinger's time-dependent equation also seemed to require a modification of the explanation for the origin of line spectra due to the apparent possibility of superpositions of energy eigenstates for different energy levels. Indeed, Schrödinger himself proposed a quantum beat mechanism for the generation of discrete line spectra from superpositions of eigenstates with different energies.However, these issues between old quantum theory and Schrödinger's wave mechanics were correctly resolved only after the development and full implementation of photon quantization. The second quantized scattering matrix formalism reconciles quantum jumps with continuous time evolution through the identification of quantum jumps with transitions between different sectors of Fock space. The continuous evolution of quantum states is then recognized as a sum over continually evolving jump amplitudes between different sectors in Fock space.In today's terminology, this suggests that linear combinations of scattering matrix elements are epistemic sums over ontic states. Insights from the resolution of the dichotomy between quantum jumps and continuous time evolution therefore hold important lessons for modern research both on interpretations of quantum mechanics and on the foundations of quantum computing. They demonstrate that discussions of interpretations of quantum theory necessarily need to take into account field quantization. They also demonstrate the limitations of the role of wave equations in quantum theory, and caution us that superpositions of quantum states for the formation of qubits may be more limited than usually expected.     

Genesis of Karl Popper's EPR-like experiment and its resonance amongst the physics community in the 1980s

I present the reconstruction of the involvement of Karl Popper in the community of physicists concerned with foundations of quantum mechanics, in the 1980s. At that time Popper gave active contribution to the research in physics, of which the most significant is a new version of the EPR thought experiment, alleged to test different interpretations of quantum mechanics. The genesis of such an experiment is reconstructed in detail, and an unpublished letter by Popper is reproduced in the present paper to show that he formulated his thought experiment already two years before its first publication in 1982. The debate stimulated by the proposed experiment as well as Popper's role in the physics community throughout 1980s is here analysed in detail by means of personal correspondence and publications.     

Effects of stress and adrenocorticotrophin administration on plasma corticosterone levels at different stages of pregnancy in the mouse.

Stress or administration of ACTH to pregnant mice gave rise to much higher plasma corticosterone levels in the second half of pregnancy than in the first half, suggesting that there may be increased adrenal sensitivity to ACTH or decreased metabolism of corticosterone during the second half of pregnancy.     

Effects of stress and adrenocorticotrophin administration on plasma corticosterone levels at different stages of pregnancy in the mouse

Summary Stress or administration of ACTH to pregnant mice gave rise to much higher plasma corticosterone levels in the second half of pregnancy than in the first half, suggesting that there may be increased adrenal sensitivity to ACTH or decreased metabolism of corticosterone during the second half of pregnancy.     

The ‘Popperian Programme’ and mathematics: Part II: From quasi-empiricism to mathematical research Programmes

In the first part of this article I investigated the Popperian roots of Lakatos's Proofs and Refutations, which was an attempt to apply, and thereby to test, Popper's theory of knowledge in a field—mathematics—to which it had not primarily been intended to apply. While Popper's theory of knowledge stood up gloriously to this test, the new application gave rise to new insights into the heuristic of mathematical development, which necessitated further clarification and improvement of some Popperian methodological maxims. In the present part I analyze this second phase in the development of Lakatos's Popperian programme in mathematics, and its connection to the methodology of scientific research programmes.     

On broken symmetries and classical systems

Baker (2011) argues that broken symmetries pose a number of puzzles for the interpretation of quantum theories—puzzles which he claims do not arise in classical theories. I provide examples of classical cases of symmetry breaking and show that they have precisely the same features that Baker finds puzzling in quantum theories. To the extent that Baker is correct that the classical cases pose no puzzles, the features of the quantum case that Baker highlights should not be puzzling either.     

1,2-di-n-butylhydrazine dihydrochloride carcinogenesis in mice

Summary A solution of 0.0625% 1,2-di-n-butylhydrazine dihydrochloride (1,2-DBH) was given continuously in the drinking water of 6-week-old randomly bred albino Swiss mice for the remainder of their lives. The treatment gave rise to tumors of the lungs, lymphoreticular tissue and kidneys.     

Socially conditioned mathematical change: the case of the French Revolution

This paper examines a historical case of conceptual change in mathematics that was fundamental to its progress. I argue that in this particular case, the change was conditioned primarily by social processes, and these are reflected in the intellectual development of the discipline. Reorganization of mathematicians and the formation of a new mathematical community were the causes of changes in intellectual content, rather than being mere effects. The paper focuses on the French Revolution, which gave rise to revolutionary developments in mathematics. I examine how changes in the political constellation affected mathematicians both individually and collectively, and how a new professional community—with different views on the objects, problems, aims, and values of the discipline—arose. On the basis of this account, I will discuss such Kuhnian themes as the role of the professional community and normal versus revolutionary development.     

量子通信现状与展望

本文综述量子通信基本原理、方法、技术手段与应用.介绍量子保密通信基本协议和诱骗态方法,以及基于纠缠分发的量子通信,含基于纠缠光子对的量子保密通信、量子态隐性传输、纠缠光子对操控等.介绍量子通信的技术与应用现状并对未来发展方向做展望.     

On conceptual issues in classical electrodynamics: Prospects and problems of an action-at-a-distance interpretation

Some conceptual issues in the foundations of classical electrodynamics concerning the interaction between particles and fields have recently received increased attention among philosophers of physics. After a brief review of the debate, I argue that there are essentially two incompatible solutions to these issues corresponding to F.A. Muller's distinction between the extension and the renormalization program. Neither of these solutions comes free of cost: the extension program is plagued with all problems related to extended elementary charges, the renormalization program works with point charges but trades in the notorious divergences of the field energies. The aim of this paper is to bring back into the discussion a third alternative, the action-at-a-distance program, which avoids both the riddles of extended elementary charges as well as the divergences although it admittedly has other problems. It will be discussed, why action-at-a-distance theories are actually not a far cry from particle–field theories, and I will argue that the main reasons for rejecting action-at-a-distance theories originate in certain metaphysical prejudices about locality and energy conservation. I will broadly suggest how these concepts could be adapted in order to allow for action at a distance.     

Arguments in favor of the extramitochondrial origin of the acetyl radical of acetylcholine synthetized in rat striatum synaptosomes]

Synaptosomes prepared from Rat striatum were loaded with (2-14C) pyruvate at 0 degree C, in the course of a 1 hr. preincubation. When temperature was raised to 37 degrees C, the intra-synaptosomal (2-14C) pyruvate gave rise to 14CO2 but not to (14C) ACh. These results exclude a mitochondrial origin of the acetyl moiety of ACh.     

Paléotempératures indiquées par l'analyse isotopique de fossiles du crétacé inférieur des Hautes-Alpes (France)

Summary Paleotemperature determinations were made by the oxygen isotope method on 20 Belemnoids, 5 Aptychi and a Nautilus beak from the Lower Cretaceous of the Dévoluy area of the Hautes-Alpes (France). The data derived show a well-defined trend from higher temperatures in the Berriasian to a climatic minimum in the Barremian followed by a rise to the Albian maximum, previously observed elsewhere in Europe. The Aptychi are shown to be useful paleotemperature indicators utilizable in conjunction with Belemnoids. A Sequanian Aptychus gave a high temperature reading, indicating that the climate steadily cooled from Upper Jurassic times into the Barremian. The single Nautilus beak gave a result suggesting that this group of fossils may also prove valuable in similar studies in the future. The paleotemperature data also showed (by the stratigraphic position of the relevant Belemnoids) that the Aptian is either very attenuated or absent in the Dévoluy.