Yorgos Goudaroulis

Some methodological and historical considerations in low temperature physics: The case of superconductivity 1911–57

Summary In this paper we study some methodological problems associated with the development of one of the major theories in low temperature physics, that of superconductivity. The first experimental results of 1911 were interpreted within a framework that hindered the paradoxical aspects of the new phenomenon. Various research programmes degenerated until new experimental results forced a reappraisal of the existing theoretical framework making possible a different formulation of the problem that had to be solved. This led to a progressive research programme, whose positive heuristic we also study.

Heike Kamerlingh Onnes' researches at Leiden and their methodological implications

Abstract The various directions of research pursued by Heike Kamerlingh Onnes while at Leiden are systematically presented, and their methodological implications discussed. We concentrate on the researches on the equation of state which, in effect, led to the liquefaction of helium; on the electrical researches which mainly involved investigations about superconductivity; and the magnetic researches which examined magnetization processes in low temperatures. Onnes developed an approach we call “sophisticated phenomenology” which, while remaining within the strict bounds of the positivist tradition, presents some interesting and distinctive features.

Understanding macroscopic quantum phenomena: The history of superfluidity 1941–1955

Summary In this paper we attempt to investigate the historical and methodological aspects of the developments related to superfluid helium, concentrating on the period between 1941 and 1955. During this period, the various developments constituted a series of steps towards redefining and refining the two-fluid concept devised to explain the unexpected macroscopic behaviour of superfluid helium. The idea that superfluids are essentially ‘quantum structures on a macroscopic scale’ functioned as a heuristic principle which guided the theoretical physicists engaged in the above research programme.

Some methodological and historical considerations in low temperature Physics II: The case of superfluidity

Summary In this paper we study some of the methodological problems associated with the development of the various theoretical schema devised to explain the phenomenon of superfluidity. The physical behaviour of supercooled helium defied explanation in terms of the known atomic laws for helium and their ‘natural’ extrapolations. We show that the basic conceptual difficulties involved were circumvented by the development of intermediate intermediaries through a process of contextual reinterpretation.

Quantum mechanics and macroscopic quantum phenomena: The case of superconductivity and superfluidity

ZusammenfassungSupraleitfähigkeit und Superfluidität sind die einzigen bekannten makroskopischen Quantenphänomene. Ihre Untersuchung liefert interessante Hinweise, um einige der Fragen zu verstehen, die mit den Grenzen der Gültigkeit der Quantenmechanik verbunden sind. In diesem Aufsatz wollen wir den Prozeß entzifferen, durch den ein beobachtetes unerwartetes Phänomen in ein physikalisches Problem übergeführt wird, und wir zeigen die kontinuierliche Reinterpretation der Begriffe, um eine zufriedenstellende Erklärung der Supraleitfähigkeit und Superfluidität zu erreichen.

Can the History of Instrumentation Tell us Anything About Scientific Practice

“While philosophers and historians commonly speak of science in terms of theory and experiment, when they speak of the development of scientific knowledge, they speak in terms of theory alone.” A decade ago, this observation was generally true. The analysis of experimentation and instrumentation is a relatively new trend in the history and philosophy of science. The post-positivistic philosophy of science tended to focus on the theoretical aspects and created a framework unfriendly to the contributions of experiment, instrumentation, and measurement to scientific knowledge.1 Until very recently, both philosophers and historians of science paid very little attention to the “everyday activities” of scientists in the laboratory.

A Matter of Order: A Controversy between Heisenberg and London

The study of controversies is not only helpful for the further understanding of the subtleties of the theories involved, but it also contributes to the clarification of a series of issues related to the problem of theory choice. Discussions and disagreements — however heated — over two theories do not necessarily entail the features of what I would like to consider as controversies. This is especially so when there is a crucial experiment that can be performed in a relatively short period. Controversies are disputes over theoretical issues, methodological questions, and not infrequently, philosophical positions. It is in this respect that controversies are also a quite suggestive probe into the conceptual framework of the various researches.

Superconductivity: the paradox that was not

The earliest attempts to formulate a theory of electrical conductivity of metals brought into prominence the variation of conductivity with temperature. As lower and lower temperatures were reached toward the end of the nineteenth century, physicists began to study the resistivity of metals as a function of temperature.

(Re-)reading the developments

The abrupt drop of the electrical resistance of mercury to almost zero, as the temperature was lowered below 4.2°K, was indeed an unexpected phenomenon, but one which did not, however, establish a paradoxical situation.1 The theories and models of electrical conductivity during the time superconductivity was discovered did not all have a unique prediction for the behaviour of the electrical resistance at very low temperatures, and the theoretical framework of the period did allow electrical resistances to become negligibly small.

“Translating” unexpected phenomena into the right physical problems

Low temperature physics is known primarily for its “peculiar” phenomena, for its elaborate technical details related to the experimental set ups used to study these phenomena, for the possibilities it offers for further understanding quantum mechanics, and for the opportunities it presents for technological applications. This area of research provides us with two unique phenomena: Superconductivity, first discovered in 1911 as the complete disappearance of electrical resistance of mercury at the critical temperature T c , of about -269°C (a little over four degrees above absolute zero); Superfluidity, first realized in 1938 after the observation that liquid helium at a temperature, T λ , of about -271°C (a little over two degrees above absolute zero) has extremely low viscosity and can pass through the narrowest capillaries. As it happens, hardly any attention has been paid to the extremely intriguing methodological issues suggested by the various attempts to find an explanation for these unique macroscopic quantum phenomena.