This chapter contains sections titled: References and Further Reading.

In the early phase of the new history of physics that emerged at about 1970 and was pioneered by John Heilbron, Thomas Kuhn, Paul Forman, and others, the quantum and atomic theories of the first three decades of the twentieth century played a central role. Since then, interest in the area has continued, but for the last few decades at a slower rate. While other areas of the new physics—such as the general theory of relativity—have attracted much attention, only relatively (...) little has been written about the quantum revolution. Given this situation, Suman Seth’s comprehensive and innovative Crafting the Quantum is a welcome publication that provides the field with fresh blood and new perspectives. The title derives from a letter to Einstein of January 1922, in which Arnold Sommerfeld wrote that “I can only advance the craft of the quantum, you have to make its philosophy.” In spite of its title, Seth’s book is neither restricted to the new quantum theory nor to Sommerfeld’s role in the tr. (shrink)

This paper examines the thoughts and early career of the astrophysicist and cosmologist E. A. Milne. Although Milne only turned to cosmology in 1932, many of the ideas that characterised his heterodox system of world physics can be traced back to his works from the 1920s. Contrary to what has been stated in the literature, we argue that Milne was familiar with and interested in cosmology even before 1932. The relationship between mathematics and physics, an important topic in Milne's cosmophysics, (...) was the subject of an unpublished paper he gave in 1922. We place the paper in its historical context and comment on its relevance for Milne's later work. An annotated transcript of the address is included as an accompanying paper under the title 'The Relations of Mathematics to Science'. (shrink)

In 1876 the Italian physicist and physical chemist Adolfo Bartoli discussed a thought experiment in which he connected the second law of thermodynamics with the hypothetical pressure of radiation. Bartoli's work, published in Italian, exerted some influence on the subsequent development of black-body theory and light pressure research. This influence was mainly due to Boltzmann, who came to the Stefan-Boltzmann radiation law via a reworking of Bartoli's thought experiment. However, contrary to what is usually assumed, Bartoli was himself reluctant to (...) admit the existence of light pressure and soon rejected the hypothesis. Bartoli's work is discussed and related to other work in the areas of radiometer research and thermodynamics. (shrink)

While Karl Popper’s philosophy of science has only few followers among modern philosophers, it is easily the view of science with the biggest impact on practicing scientists. According to Peter Medawar, Nobel laureate and eminent physiologist, Popper was the greatest authority ever on the scientific method. He praised the “great strength of Karl Popper’s conception of the scientific process,” a main reason for the praise being “that it is realistic—it gives a pretty fair picture of what goes on in real (...) life laboratories” (Medawar 1990, p. 100). Either explicitly or (more often) implicitly, many scientists subscribe to some version of simplified Popperianism, usually by adopting the demarcation criterion that a .. (shrink)

The case of Fred Hoyle’s prediction of a resonance state in carbon-12, unknown in 1953 when it was predicted, is often mentioned as an example of anthropic prediction. However, an investigation of the historical circumstances of the prediction and its subsequent experimental confirmation shows that Hoyle and his contemporaries did not associate the level in the carbon nucleus with life. Only in the 1980s, after the emergence of the anthropic principle, did it become common to see Hoyle’s prediction as anthropically (...) significant. At about the same time mythical accounts of the prediction and its history began to abound. Not only has the anthropic myth no basis in historical fact, it is also doubtful if the excited levels in carbon-12 and other atomic nuclei can be used as an argument for the predictive power of the anthropic principle. (shrink)

Summary Apart from hydrogen, helium is the most abundant chemical element in the universe, and yet it was only discovered on the Earth in 1895. Its early history is unique because it encompasses astronomy as well as chemistry, two sciences which the spectroscope brought into contact during the second half of the nineteenth century. In the modest form of a yellow spectral line known as D3, ‘helium’ was sometimes supposed to exist in the Sun's atmosphere, an idea which is traditionally (...) ascribed to J. Norman Lockyer. Did Lockyer discover helium as a solar element? How was the suggestion received by chemists, physicists and astronomers in the period until the spring of 1895, when William Ramsay serendipitously found the gas in uranium minerals? The hypothetical element helium was fairly well known, yet Ramsay's discovery owed little or nothing to Lockyer's solar element. Indeed, for a brief while it was thought that the two elements might be different. The complex story of how helium became established as both a solar and terrestrial element involves precise observations as well as airy speculations. It is a story that is unique among the discovery histories of the chemical elements. (shrink)

This book presents the history of how the universe at large became the object of scientific understanding. Starting with the ancient creation myths, it offers an integrated and comprehensive account of cosmology that covers all major events from Aristotle's Earth-centred cosmos to the recent discovery of the accelearting universe.

During the last decade new developments in theoretical and speculative cosmology have reopened the old discussion of cosmology's scientific status and the more general question of the demarcation between science and non-science. The multiverse hypothesis, in particular, is central to this discussion and controversial because it seems to disagree with methodological and epistemic standards traditionally accepted in the physical sciences. But what are these standards and how sacrosanct are they? Does anthropic multiverse cosmology rest on evaluation criteria that conflict with (...) and go beyond those ordinarily accepted, so that it constitutes an “epistemic shift” in fundamental physics? The paper offers a brief characterization of the modern multiverse and also refers to a few earlier attempts to introduce epistemic shifts in the science of the universe. It further discusses the several meanings of testability, addresses the question of falsifiability as a sine qua non for a theory being scientific, and briefly compares the situation in cosmology with the one in systematic biology. Multiverse theory is not generally falsifiable, which has led to proposals from some physicists to overrule not only Popperian standards but also other evaluation criteria of a philosophical nature. However, this is hardly possible and nor is it possible to get rid of explicit philosophical considerations in some other aspects of cosmological research, however advanced it becomes. (shrink)

The controversy between Alfred Werner and Sophus Mads Jørgensen over the structure of complex inorganic compounds is not among the best known of the many controversies in the history of chemistry, but it is one of the most thoroughly described in the historical literature. This is due almost solely to the works of George Kauffman, the distinguished American historian of chemistry and specialist in the history of coordination chemistry. Kauffman has described and analysed almost every aspect of the development of (...) coordination chemistry and has in several works dealt with the Werner–Jørgensen controversy which ran from 1894 to 1899. Because of Kauffman's expertise and many works in the area, his account is likely to be taken as authoritative and his conclusions repeated in later historical works. This paper argues that this is unwarranted at least in one particular respect, namely the evaluation of Jørgensen and the way the controversy terminated. Kauffman's version of this episode has frequently appeared in print during a period of thirty-five years, first in 1959 and most recently in 1994. My conclusion is that it cannot survive critical examination. (shrink)

During the last decade new developments in theoretical and speculative cosmology have reopened the old discussion of cosmology’s scientific status and the more general question of the demarcation between science and non-science. The multiverse hypothesis, in particular, is central to this discussion and controversial because it seems to disagree with methodological and epistemic standards traditionally accepted in the physical sciences. But what are these standards and how sacrosanct are they? Does anthropic multiverse cosmology rest on evaluation criteria that conflict with (...) and go beyond those ordinarily accepted, so that it constitutes an “epistemic shift” in fundamental physics? The paper offers a brief characterization of the modern multiverse and also refers to a few earlier attempts to introduce epistemic shifts in the science of the universe. It further discusses the several meanings of testability, addresses the question of falsifiability as a sine qua non for a theory being scientific, and briefly compares the situation in cosmology with the one in systematic biology. Multiverse theory is not generally falsifiable, which has led to proposals from some physicists to overrule not only Popperian standards but also other evaluation criteria of a philosophical nature. However, this is hardly possible and nor is it possible to get rid of explicit philosophical considerations in some other aspects of cosmological research, however advanced it becomes. (shrink)

The history of the Greenlandic mineral cryolite is outlined from its discovery in late-eighteenth century to the mid-nineteenth century, when its potential for industrial use was first recognized by the Danish chemist Julius Thomsen. During the 1850s, several attempts were made to exploit cryolite for the production of soda and/or aluminium, of which only the soda process became implemented on an industrial scale. The main part of the paper examines the early cryolite soda manufacture, its chemical basis as well as (...) its industrial significance. The focus is thus the intersection of chemical science and technology. It is argued that Thomsen's process depended intimately on current chemical knowledge, and that, with regard to the science-technology relationship, the cryolite soda manufacture signified a new kind of industrial chemistry. (shrink)

Danish astronomy in the first half of the seventeenth century reflected the enduring legacy of Tycho Brahe and was dominated by his former assistant Longomontanus. This paper focuses on his successor as professor of astronomy, Jørgen From or Georgius Frommius in the Latin version, who was also the second director of the Round Tower observatory in Copenhagen. Before becoming a professor, Frommius travelled to the Netherlands and other countries. The letters from his journey cast light on the training of a (...) young astronomer at the time. He most likely was the first Dane to observe the heavens with a telescope. In the 1640s, he got involved in a controversy with the French astronomer and astrologist Jean Morin, and he later contributed to Pierre Gassendi’s pioneering biography of Tycho Brahe. Although Frommius died at the age of 46, his brief career as professor and astronomer is of interest to national as well as international history of science. (shrink)

By 1870, non-Euclidean geometry had been established as a mathematical research field but was yet to be considered relevant to the real space inhabited by stars and nebulae. It was of much less interest to physicists and astronomers than to mathematicians and philosophers. Although most astronomers took the age-old Euclidean geometry for granted, during the following decades a few of them such as K. F. Zöllner, S. Newcomb and K. Schwarzschild followed in the footsteps of the pioneer N. I. Lobachevsky (...) by seriously considering the possibility that cosmic space might be curved. From the H. Poincaré’s conventionalist perspective the discussion was meaningless since there was no way in which observations or other empirical data could determine the geometry of space. Poincaré’s view was shared by a few astronomers, but its impact on astronomy was limited. The paper examines the question as it was discussed prior to the advent of the general theory of relativity. (shrink)

Ideological considerations have always influenced science, butrarely as directly and massively as in the Soviet Union during the early Cold War period, when cosmology was among the sciences that became politicized. This field of science developed very differently in the Communist countries than in the West, in large measure because of political pressure. Certain cosmological models, in particular of the big bang type, were declared pseudo-scientific and idealistic because they implied a cosmic creation, a concept which was taken to be (...) religious. The result of the ideological pressure was not an independent Soviet cosmology, but that astronomers and physicists abandoned cosmological research in the Western sense. Onlyin the 1960s did this situation change, and cosmology in the Soviet Union began to flourish. The paper reviews the relationship between cosmology and political ideology in the Soviet Union from about 1947 to 1963, and it briefly relates this case to the later one in the People’s Republic of China. (shrink)

SummaryIn the history of chemistry, the Danish chemist Julius Thomsen (1826–1909) is best known for his contributions to thermochemistry. Throughout his life, he was a pronounced atomist and a tireless advocate of neo-Proutian views as to the constitution of matter. On many occasions, especially in his later years, he engaged in speculations concerning the unity of matter and the complexity of atoms. In this engagement, Thomsen was alone in Danish chemistry, but his works were representative of a large number of (...) 19th-century chemists, particularly in England and Germany. Thomsen's ideas as to the constitution of matter, the periodic system and the noble gases, may be seen as typical of this vigorous trend in fin de siècle chemistry. (shrink)

Problems of scientific cosmology only rarely occur in the works of Karl Popper. Nevertheless, it was a subject that interested him and which he occasionally commented on. What is more important, his general claim of falsifiability as a criterion that demarcates science from non-science has played a significant role in periods of the development of modern physical cosmology. The paper examines the historical contexts of the interaction between cosmology and Popperian philosophy of science. Apart from covering Popper’s inspiration from Einstein (...) and his views on questions of cosmology, it focuses on the impact of his thoughts in two periods of controversy of modern cosmology, the one related to the steady state theory and the other to the recent multiverse proposal. It turns out that the impact has been considerable, and continues to be so, but also that the versions of Popperian methodology discussed by cosmologists are sometimes far from what Popper actually thought and wrote. (shrink)

Attempts to explain the periodic system as a manifestation of regularities in the structure of the atoms of the elements are as old as the system itself. The paper analyses some of the most important of these attempts, in particular such works that are historically connected with the recognition of the electron as a fundamental building block of all matter. The history of the periodic system, the discovery of the electron, and ideas of early atomic structure are closely interwoven and (...) transcend the physics–chemistry boundary. It is pointed out that J. J. Thomson's discovery of the electron in 1897 included a first version of his electron atomic model and that it was used to suggest how the periodic system could be understood microphysically. Thomson's theory did not hold what it promised, but elements of it were included in Niels Bohr's first atomic model. In both cases, Thomson's and Bohr's, the periodic system played an important role, heuristically as well as justificatory. (shrink)

The aim of this book, written by a researcher at the Tatarstan Academy of Sciences, is to examine how and why theories change in science. Nugayev’s analysis, and his many examples, are confined to mathematically formalized theories of physics. Nugayev’s ideas are inspired by, and relate to, Russian scholars. His approach is primarily philosophical and clearly in the analytical tradition of Popper, Kuhn, Lakatos, Feyerabend, Stegmuller and others. Although Nugayev’s book is primarily addressed to philosophers, it is also of interest (...) to the philosophically inclined historian of science. (shrink)

SUMMARYFaced 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. (shrink)

Summary The emergence of quantum theory in the early decades of the twentieth century was accompanied by a wide range of popular science books, all of which presented in words, and a few in images, new scientific ideas about the structure of the atom. The work of physicists such as Ernest Rutherford and Niels Bohr, among others, was pivotal to the so-called planetary model of the atom, which, still today, is used in popular accounts and in science textbooks. In an (...) attempt to add to our knowledge about the popular trajectory of the new atomic physics, this paper examines one book in particular, co-authored by Danish science writer Helge Holst and Dutch physicist and close collaborator of Niels Bohr, Hendrik A. Kramers. Translated from Danish into four European languages, the book not only explained contemporary ideas about the quantum atom, but also discussed unresolved problems. Moreover, the book was quite explicit in identifying the quantum atom with the atom as described by Bohr's theory. We argue that Kramers and Holst's book, along with other ‘atomic books’, was a useful tool for physicists and science popularisers in trying to understand the new quantum physics. (shrink)

Among the subjects that attract historians of chemistry and philosophers of chemistry alike are the chemical elements and their classification within the periodic system. In 2007, Eric Scerri, a distinguished philosopher of the chemical sciences, published The Periodic Table (Oxford University Press), a comprehensive and critical account of the subject. He describes the present work as “a follow-up book,” and a few of the chapters are indeed condensed versions of chapters appearing in the 2007 book. Nonetheless, A Tale of 7 (...) Elements has a different scope and also a different intended audience. It is a story of seven little-known elements, some of which—such as promethium, francium and astatine—are extremely rare and with almost no applications. While Scerri’s 2007 book was in the more traditional academic genre, this one appeals to an audience much wider than the limited community of historians and philosophers of science. It is a brave and largely successful attempt to bridge the infa .. (shrink)

The precise position of a spectral line emitted by an atomic system depends on the mass of the atomic nucleus and is therefore different for isotopes belonging to the same element. The possible presence of an isotope effect followed from Bohr's atomic theory of 1913, but it took several years before it was confirmed experimentally. Its early history involves the childhood not only of the quantum atom, but also of the concept of isotopy. Bohr's prediction of the isotope effect was (...) apparently at odds with early attempts to distinguish between isotopes by means of their optical spectra. However, in 1920 the effect was discovered in HCl molecules, which gave rise to a fruitful development in molecular spectroscopy. The first detection of an atomic isotope effect was no less important, as it was by this means that the heavy hydrogen isotope deuterium was discovered in 1932. The early development of isotope spectroscopy led to successes as well as problems. At the end of the paper I briefly comment on the relationship between theory, experiment and prediction in this area of spectral physics. (shrink)

This is a transcript of Milne's manuscript notes for a talk which he gave to fellow members of the Cambridge University Natural Science Club in his rooms at Trinity College, Cambridge, on February 6, 1922. The notes are deposited in the Bodleian Library, University of Oxford, Special Collections and Western Manuscripts. The background and essential points of Milne's talk are analysed in the article preceding this one. As far as is known, the text has not hitherto been published. Milne's handwriting (...) is difficult to read, and square brackets [...] denote the addition of a word for clarity of meaning. Meg Weston Smith and Simon Rebsdorf have ventured to fill in some chapter titles just in order to help with the separation of the varying content, hence we have made up all the headlines. All italics correspond to underlined words in the original. The Bergson citations and the Eddington passage at the end of the original text have not been transcribed. (shrink)

Short review of Helge Kragh's excellent book on the contest between big bang and steady state theories of the universe.