We briefly describe in this paper the passage from Mendeleev’s chemistry (1869) to atomic physics (in the 1900’s), nuclear physics (in 1932) and particle physics (from 1953 to 2006). We show how the consideration of symmetries, largely used in physics since the end of the 1920’s, gave rise to a new format of the periodic table in the 1970’s. More specifically, this paper is concerned with the application of the group SO(4,2)⊗SU(2) to the periodic table (...) of chemical elements. It is shown how the Madelung rule of the atomic shell model can be used to set up a periodic table that can be further rationalized via the group SO(4,2)⊗SU(2) and some of its sub-groups. Qualitative results are obtained from this nonstandard table. (shrink)

These articles and speeches by the Nobel Prize-winning physicist date from 1934 to 1958. Rather than expositions on quantum physics, the papers are philosophical in nature, exploring the relevance of atomic physics to many areas of human endeavor. Includes an essay in which Bohr and Einstein discuss quantum and_wave equation theories. 1961 edition.

The prolongation of lifetimes for an excited atom due to the presence of nearby atoms in the ground state is shown to follow simply from unitarity of the time evolution. We also discuss possible approaches to the detection and the overcoming of various technical obstacles.

The issue of shifting scales between the microscopic and the macroscopic dimensions is a recurrent one in the history of science, and in particular the history of microscopy. But it took on new dimensions in the context of early twentieth-century microscophysics, with the progressive realisation that the physical laws governing the macroscopic world were not always adequate for describing the sub-microscopic one. The paper focuses on the researches of Jean Perrin in the 1900s, in particular his use of Brownian motion (...) to produce evidence of the existence of atoms and in favour of the kinetic theory. His results were described by many contemporaries, and subsequently by historians, as the first direct proof of atomic and molecular reality. The paper examines the different strategies developed by Perrin for bridging the macro and sub-microphysical realms and making the latter accessible to the senses; even though neither atoms nor molecules were ever actually seen, and in fact very few visual representations were shown and published in connection with these experiments. This case provides a good example of how visualizing, representing and convincing could be interwoven in the production of evidence about the sub-microphysical realm circa 1900.Keywords: Jean Perrin; Brownian motion; Ultramicroscope; Evidence; Atom; Atomism. (shrink)

This paper suggests that the cases made for atoms and the aether in nineteenth-century physical science were analogous, with the implication that the case for the atom was less than compelling, since there is no aether. It is argued that atoms did not play a productive role in nineteenth-century chemistry any more than the aether did in physics. Atoms and molecules did eventually find an indispensable home in chemistry but by the time that they did so they were different (...) kinds of entities to those figuring in the speculations of those natural philosophers who were atomists. Advances in nineteenth-century chemistry were a precondition for rather than the result of the productive introduction of atoms into chemistry. (shrink)

Introduction -- Light and life -- Biology and atomic physics -- Natural philosophy and human cultures -- Discussion with Einstein on epistemological problems in atomic physics -- Unity of knowledge -- Atoms and human knowledge -- Physical science and the problem of life.

In this paper I shall explore a novel alternative to these familiar views. In his recent book Sub ects of Ex erience, E. J. Lowe argues, as many others have done before, that you and I are not animals. It follows from this, he says, that we must be simple substances without parts. That may sound like Cartesian dualism. But Lowe is no Cartesian. He argues from premises that many present-day materialists accept. And he claims that our being mereologically simple (...) is consistent with our having such paradigmatically physical properties as being six feet tall and weighing 160 pounds. You and I, he claims, are mereological atoms shaped like human beings. (shrink)

ArgumentThis paper discusses one aspect of the context in which atomic physics developed in Japan between 1905 and 1931. It argues that during this period, there was a social context in which atomic physics was valued as a study of the electron and was thus relevant to electrical engineering. To demonstrate this, I first show that after the Russo-Japanese War, electrical engineering was deemed a valuable and viable field of research in Japan. Second, I show that (...) physicists wrote textbooks and popular accounts about the electron, covering topics from both atomic physics and electrical engineering and presenting the former as relevant to the latter. Finally, as an example of how atomic physics partially emerged from this context, I discuss the group of Kujirai Tsunetarō, an electrical engineer who worked in the physics department of the Institute for Physical and Chemical Research. From Kujirai's group, Nishina Yoshio started his career and became the most important Japanese atomic and nuclear physicist of the 1930s. (shrink)

Quantum Logic in Historical and Philosophical Perspective Quantum Logic was developed as an attempt to construct a propositional structure that would allow for describing the events of interest in Quantum Mechanics. QL replaced the Boolean structure, which, although suitable for the discourse of classical physics, was inadequate for representing the atomic realm. The … Continue reading Quantum Logic →.

In the centennial of Ettore Majorana’s birth (1906–1938?), we re-examine some aspects of his fundamental scientific production in atomic and molecular physics, including a not well known short communication. There, Majorana critically discusses Fermi’s solution of the celebrated Thomas–Fermi equation for electron screening in atoms and positive ions. We argue that some of Majorana’s seminal contributions in molecular physics already prelude to the idea of exchange interactions (or Heisenberg–Majorana forces) in his later works on theoretical nuclear (...) class='Hi'>physics. In all his papers, he tended to emphasize the symmetries at the basis of a physical problem, as well as the limitations, rather than the advantages, of the approximations of the method employed. (shrink)

In this paper we analyse the approach to interpreting atomic spectra in the framework of classical physics from the discovery of the electron in 1897 to Bohr's atomic model of 1913. Taken as a whole, efforts in this direction are part of a remarkable intellectual endeavour in which the classical theoretical framework seems to have been exploited to its full potential. By demonstrating the limits and weaknesses of classical physics in solving the problem of spectral emissions, (...) these attempts opened the way to a complete break from traditional thought and the introduction of the new quantum ideas. (shrink)

In the future, magic, prophecy, and faith, as well as the usual thought patterns of classical philosophy, but also revelations, will no longer serve to convey to people the meaning of existence. The book shows how they are superseded by the modern physical theory of matter. This has far-reaching implications since there is no possibility for the existence of a (creating) God and the cosmos has to be regarded as a "split zero". In addition the book presents an outline for (...) a cosmic ethic, which calls for mutual respect and mutual assistance between all people. (shrink)

In the long history of science there is nothing quite like the famous dialogue which ensued between Albert Einstein and Neils Bohr about the validity and meaning of the new quantum theory. By 1927 when the first public debate took place, both men stood at the top of their profession. Einstein was the creator of the Special and General theories of relativity and also had made major contributions to atomic theory. Bohr had developed the successful model of the hydrogen (...) atom in 1913 and his two principles of correspondence and complementarity had established the relationship between classical physics and the new physics of the atom. MacKinnon treats this Bohr-Einstein dialogue as the centerpiece and climax of his book on the history of Atomism from a philosophical perspective. It is a carefully written and closely argued discussion of the contributions of significant scientists and philosophers of science to the perennial question about nature: is it made up of discrete nonreducible parts or is it continuous and infinitely divisible? (shrink)

In this stimulating investigation, Gideon Freudenthal has linked social history with the history of science by formulating an interesting proposal: that the supposed influence of social theory may be seen as actual through its co herence with the process of formation of physical concepts. The reinterpre tation of the development of science in the seventeenth century, now widely influential, receives at Freudenthal's hand its most persuasive statement, most significantly because of his attention to the theoretical form which is charac teristic. (...) of classical Newtonian mechanics. He pursues the sources of the parallels that may be noted between that mechanics and the dominant philosophical systems and social theories of the time; and in a fascinating development Freudenthal shows how a quite precise method - as he descriptively labels it, the 'analytic-synthetic method' - which underlay the Newtonian form of theoretical argument, was due to certain interpretive premisses concerning particle mechanics. If he is right, these depend upon a particular stage of con ceptual achievement in the theories of both society and nature; further, that the conceptual was generalized philosophically; but, strikingly, Freudenthal shows that this concept-formation itself was linked to the specific social relations of the times of Newton and Hobbes. (shrink)

In 1932, Wolfgang Pauli was a world-renowned physicist and had already done the work that would win him the 1945 Nobel Prize. He was also in pain. His mother had poisoned herself after his father's involvement in an affair. Emerging from a brief marriage with a cabaret performer, Pauli drank heavily, quarreled frequently and sometimes publicly, and was disturbed by powerful dreams. He turned for help to C. G. Jung, setting a standing appointment for Mondays at noon. Thus bloomed an (...) extraordinary intellectual conjunction not just between a physicist and a psychologist but between physics and psychology. Eighty letters, written over twenty-six years, record that friendship. This artful translation presents them in English for the first time. Though Jung never analyzed Pauli formally, he interpreted more than 400 of his dreams--work that bore fruit later in Psychology and Alchemy and The Analysis of Dreams. As their acquaintance developed, Jung and Pauli exchanged views on the content of their work and the ideas of the day. They discussed the nature of dreams and their relation to reality, finding surprising common ground between depth psychology and quantum physics. Their collaboration resulted in the combined publication of Jung's treatise on synchronicity and Pauli's essay on archetypal ideas influencing Kepler's writings in The Interpretation of Nature and the Psyche. Over time, their correspondence shaped and reshaped their understanding of the principle they called synchronicity, a term Jung had suggested earlier. Through the association of these two pioneering thinkers, developments in physics profoundly influenced the evolution of Jungian psychology. And many of Jung's abiding themes shaped how Pauli--and, through him, other physicists--understood the physical world. Of clear appeal to historians of science and anyone investigating the life and work of Pauli or Jung, this portrait of an incredible friendship will also draw readers interested in human creativity as well as those who merely like to be present when great minds meet. (shrink)

Ellis argues that certain essential properties of objects in the world not only determine the nature of these objects but also how they will behave in any situation. In this paper I will critique Ellis's essentialism from the perspective of the philosophy of chemistry, arguing that our current knowledge of chemistry in fact does not lend itself to essentialist interpretations and that this seriously undercuts Ellis's project. In particular I will criticize two key distinctions Ellis draws between internal vs. external (...) properties and essential vs. accidental properties, showing that at the chemical level such distinctions are insupportable. If essential properties only exist at the level of sub-atomic physics, then Ellis's hopes that essentialism will provide a theoretical basis for a philosophy of chemistry are at best hopes for a very distant future, since the argument that chemical structure and dynamics can be explained at the quantum level derived is purely from analogy to much simpler systems than those chemists actually study. This suggests that we have very little scientific evidence that scientific essentialism is a viable ontology. †To contact the author, please write to: Department of Philosophy, University of Notre Dame, Notre Dame, IN 46556; e-mail: [email protected]. (shrink)

Contemporary arguments for forms of psycho-physical dualism standardly depart from phenomenal aspects of consciousness. Conceptual aspects of conscious experience, as opposed to phenomenal or visual/perceptual ones, are often taken to be within the scope of functionalist, reductionist, or physicalist theories. I argue that the particular conceptual structure of human consciousness makes this asymmetry unmotivated. The argument for a form of dualism defended here proceeds from the empirical premise that conceptual structure in a linguistic creature like us is a combinatorial and (...) compositional system that implicates a distinction between simple and complex, or 'atomic' and 'molecular' concepts. The argument is that conceptual atoms, qua atoms, are irreducible to anything else. If so, and if the atoms are essentially semantic, a form of dualism follows: though positively inviting naturalistic inquiry into the semantic and mental aspects of nature, it requires that we look at the mental as a primitive domain of nature. Schematically, then, the argument is as follows: Human consciousness/thought is conceptually structured. The human conceptual system is a 'particulate' system at a syntactic and semantic level of representation. This implies the existence of conceptual 'particles', concepts that have no further semantic decomposition. A conceptual atom cannot be explained in terms of anything that does not involve its own intrinsic properties. Physicalism as normally conceived is inconsistent with and. (shrink)

One of the most dramatic advances in the physical sciences during the nineteenth century was the emergence of spectroscopy. It rapidly became an invaluable experimental technique for chemists and astronomers, while for physicists it opened a window upon the world of sub-atomic phenomena. Sir John Herschel played an important part, the value of which has sometimes been underestimated, in the early development of spectroscopy. This paper examines his contribution to the subject during the period 1819–61 in the light of (...) his publications and of certain manuscript material preserved in the Royal Society's Library. Herschel corresponded with most of the scientists who did important work in spectroscopy during his lifetime, and he expressed definite opinions on most of the practical and theoretical problems that arose in it; however, the present study cannot pretend to offer a complete discussion of all aspects of the early history of spectroscopy. (shrink)

Does chemistry reduce to physics? If this means ‘Can we derive the laws of chemistry from the laws of physics?’, recent discussions suggest that the answer is ‘no’. But sup posing that kind of reduction—‘epistemological reduction’—to be impossible, the thesis of ontological reduction may still be true: that chemical properties are determined by more fundamental properties. However, even this thesis is threatened by some objections to the physicalist programme in the philosophy of mind, objections that generalize to the (...) chemical case. Two objections are discussed: that physicalism is vacuous, and that nothing grounds the asymmetry of dependence which reductionism requires. Although it might seem rather surprising that the philosophy of chemistry is affected by shock waves from debates in the philosophy of mind, these objections show that there is an argumentative gap between, on the one hand, the theoretical connection linking chemical properties with properties at the sub-atomic level, and, on the other, the philosophical thesis of ontological reduction. The aim of this paper is to identify the missing premises (among them a theory of physical possibility) that would bridge this gap. Introduction: missing elements and the mystery of discreteness The refutation of physicalism A combinatorial theory of physical possibilia Combinatorialism and the Bohr model Objections The missing premises and a disanalogy with mind. (shrink)

The scientific conception of change and motion raises two fundamental questions: Is there any evidence that the temporal order of events cannot legitimately be postulated to be continuous in Cantor's sense? Is it possible to account for such distinguishing properties of time as its possession of an "arrow" on the basis of assuming that events constitute a continuous type of order in Cantor's sense, and providing a coordinating definition for the ordering relation "later than"? We must raise these questions, since (...) at least four philosophers of the present century have denied the compatibility of the temporal structure of actual events with the order defined by Cantor's linear continuum and have held that a description of physical change which is based on the latter type of order is incompetent to account for the "arrow" of time and for such features of actual events as the latter involves. The philosophers in question are Henri Bergson, William James, Alfred North Whitehead and Paul Weiss. Each of these thinkers makes reference to Zeno's paradoxes of motion in setting forth his arguments. (shrink)

The path to a new discovery in physics is often a very twisted one. The subject of this Alternate View column is an example of this process. A major accelerator, built with with the prospect of discovering super-heavy elements, is now being used in an experiment to produce "super-atoms" with very large electric fields, and this work has quite unexpectedly revealed what looks like a new and mysterious particle. It is reminiscent of the SF of the 1930's where one (...) of the standard science gimmicks was the discovery of a new element with amazing properties. It also sounds a bit like the Paul Preuss novel Broken Symmetries, where the plot revolves around the discovery at a large accelerator laboratory of a mysterious new particle. But this is real science, folks. Honest! (shrink)

It is usually claimed that the Laguerre polynomials were popularized by Schrödinger when creating wave mechanics; however, we show that he did not immediately identify them in studying the hydrogen atom. In the case of relativistic Dirac equations for an electron in a Coulomb field, Dirac gave only approximations, Gordon and Darwin gave exact solutions, and Pidduck first explicitly and elegantly introduced the Laguerre polynomials, an approach neglected by most modern treatises and articles. That Laguerre polynomials were not very popular (...) before their use in quantum mechanics, probably because they had been little used in classical mathematical physics, is confirmed by the fact that, as we show, they had been rediscovered independently several times during the nineteenth century, in published or unpublished studies of Abel, Murphy, Chebyshev, and Laguerre. (shrink)

J. Robert Oppenheimer was one of the outstanding physicists of his generation. He was also an immensely gifted writer and speaker, who thought deeply about the way that scientific discoveries have changed the way people live and think. Displaying his subtlety of thought and expression as do few other documents, this book of his lectures discusses the moral and cultural implications of developments in modern physics.