The Ensemble Interpretation of Quantum Mechanics and Scientific Realism

The article takes under consideration three versions of the ensemble (statistical) interpretation of quantum mechanics and discusses the interconnection of these interpretations with the philosophy of science. To emphasize the specifics of the problem of interpretation of quantum mechanics in the USSR, the Marxist ideology is taken into account. The present paper continues the author’s previous analysis of ensemble interpretations which emerged in the USA and USSR in the first half of the 20th century. The author emphasizes that the ensemble approach turned out to be a dead end for the development of the interpretation of quantum mechanics in Russia. The article also argues that in Soviet Russia, the classical Copenhagen (standard) approach to quantum mechanics was used. The Copenhagen approach was developed by Lev Landau in 1919–1931 and became the basis of the Landau-Lifshitz famous course on quantum mechanics, one of the classics of twentieth-century physics literature (the first edition was published in 1947). Although Vladimir A. Fock’s approach to the interpretation of quantum mechanics differs from the standard presentation by Lev Landau and Evgeny Lifshitz, Fock put forward a very important principle that complementarity is a “firmly established law of nature”. The fundamental writings of Lev Landau, Vladimir Fock and Igor Tamm, the authors of the mid-twentieth century, did a lot to defend the standard point of view such as the popular interpretations by Landau and Lifshitz. This approach can be traced back to Landau’s early writings and to Fock’s criticism of the ensemble approach.

The Love of His Life

The solid state physics community is electrified when Bardeen, Cooper, and Schrieffer (BCS) announce their discovery of a microscopic model capable of explaining the phenomenon of superconductivity,which is observed in some metals at very low temperature. To understand Anderson’s contributions to this subject, this chapter begins with the phenomenology of superconductivity and then sketches a few key aspects of many-electron theory, including the concepts of collective excitations and quasiparticles. Anderson explains the apparent lack of gauge invariance of the BCS approach and then uses a sophisticated approximation to study the excited states of a superconductor. He travels to Russia where his theory gains the approval of Lev Landau and he demonstrates how to analyze so-called dirty superconductors. He collaborates indirectly with Robert Schrieffer to generalize the BCS model into a full-blown theory capable of describing any material where the electron-phonon interaction drives superconductivity.

Uma introdução à Teoria de Landau para Líquidos de Fermi

Resumo Apresentamos uma introdução à Teoria de Landau para Líquidos de Fermi. Procuramos evidenciar os paradigmas estabelecidos por Lev Landau nos anos 50, que têm impacto para o desenvolvimento de áreas de pesquisa até os dias atuais. Por sua vez, argumentamos que é possível o ensino dessa teoria em cursos de graduação em física, tendo um impacto positivo na construção do conhecimento de profissionais de áreas como Estado Sólido e Elétrons Fortemente Correlacionados. A apresentação é construtiva, autocontida e voltada para alunos de graduação e pós graduação em Física. A modo de exemplo, estudamos a propagação de ondas em um modelo simplificado de líquido de Fermi bidimensional. Relacionamos o resultado com um dos cálculos mais conhecidos de Landau, as excitações de “som zero”.

Lev Landau. Ukraine, Kharkiv, UPTI

It was Lev Davidovich Landau who founded the Kharkiv scientific school of theoretical physics in 1932–1937.

Modelling of motorway bridge spans under modernization with consideration of rheological properties of the materials

The paper presents a computer modelling technique for modernization of bridgework operations by building-up a mounted reinforced concrete slab. It implements the technique of the evolutionary transformation of a model in one calculation cycle with redistribution of forces between the elements of the built-up section, and consideration of the impact of elastoplastic and rheological properties of the materials. Consideration of the concrete creep implies the application of the generalized kinetic curve of prolonged deformation and phenomenological deformation development equations based on the colloid-chemical concept of the prolonged concrete deformation mechanism. The creep control was implemented through new structural coefficients which determined the structure of matrix interlayers between the sand grains, and mortar between the crushed stone grains. The technique proposed was realized in the program complex “LIRA-SAPR” based on the building information modelling (BIM) and the finite element method (FEM). The multistage modelling technique was shown by an example of calculation of a motorway bridge slab span within the transport structures under modernization along the Lev Landau Avenue in Kharkiv (Ukraine).

A grande ciência de Stalin

Níveis excepcionalmente elevados de avanços científicos e tecnológicos, bem como de violência e repressão política, caracterizaram o período da história da União Soviética sob a ditadura de Stalin. O caso do físico teórico Lev Landau (1908- 1968) fornece uma oportunidade para estudar o emaranhamento entre essas duas distintivas características do sistema político soviético. O comprometimento de Landau tanto com a revolução científica quanto com a revolução política foi representativo da cultura estudantil radical dos anos 1920. Experiências existenciais especificamente soviéticas contribuíram para as realizações mais significativas de Landau na física quântica: elas se expressaram, especialmente, na teoria coletivista de matéria quântica que ele desenvolveu em conjunto com vários outros físicos soviéticos.