Olival Freire

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with the Copenhagen group, the existence and content of which have been only recently disclosed by the discovery of unpublished documents.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.

Does an Emphasis on the Concept of Quantum States Enhance Students' Understanding of Quantum Mechanics?

Teaching physics implies making choices. In the case of teachingquantum physics, besides an educational choice – the didactic strategy – another choice mustbe made, an epistemological one, concerning the interpretation of quantum theory itself. Thesetwo choices are closely connected. We have chosen a didactic strategy that privileges the phenomenological-conceptualapproach, with emphasis upon quantum features of the systems, instead of searching for classicalanalogies. This choice has led us to present quantum theory associated with an orthodox, yet realistic,interpretation of the concept of quantum state, considered as the key concept of quantum theory,representing the physical reality of a system, independent of measurement processes. The results of theimplementation of this strategy, with three groups of engineering students, showed that more than a halfof them attained a reasonable understanding of the basics of quantum mechanics (QM) for thislevel. In addition, a high degree of satisfaction was attained with the classes as 80% of thestudents of the experimental groups claimed to have liked it and to be interested in learning more about QM.

Philosophy enters the optics laboratory: Bell's theorem and its first experimental tests (1965–1982)

Abstract This paper deals with the ways that the issue of completing quantum mechanics was brought into laboratories and became a topic in mainstream quantum optics. It focuses on the period between 1965, when Bell published what we now call Bells theorem, and 1982, when Aspect published the results of his experiments. Discussing some of those past contexts and practices, I show that factors in addition to theoretical innovations, experiments, and techniques were necessary for the flourishing of this subject, and that the experimental implications of Bells theorem were neither suddenly recognized nor quickly highly regarded by physicists. Indeed, I will argue that what was considered good physics after Aspects 1982 experiments was once considered by many a philosophical matter instead of a scientific one, and that the path from philosophy to physics required a change in the physics communitys attitude about the status of the foundations of quantum mechanics.

A formulação dos 'estados relativos' da teoria quântica

The purpose of this paper is to present, in a pedagogical manner and in Portuguese, the relative state formulation of quantum mechanics, published by Hugh Everett in 1957. In this presentation, we rewrite the original arguments using Diracs formalism in order to facilitate their understanding. Furthermore, we point out the main problems encountered by Everetts interpretation. The presentation focuses on Everetts original papers and manuscripts, rather than on the subsequent interpretations of Everetts work, which attached a strong ontological meaning to its alleged implications.

A Graduate Programme in History, Philosophy and Science Teaching in Brazil

This paper discusses a Masters degree in History, Philosophy and Science Teaching recently created in Brazil. The paper will report alocal experience but its analysis raises questions of general interest, in particular to less developed countries. This interest concerns firstly the challenges of doing research and educating people in science teaching, and developing a scientific culture, and secondly the institutional obstacles that face new and/or interdisciplinary research groups. We anticipate the conclusion that in Brazilian conditions of today projects from emergent andinterdisciplinary groups can be damaged by political, cultural and institutionalobstacles.

A "crítica forte" da ciência e implicações para a educação em ciências

Neste trabalho discutimos alguns elementos oriundos tanto do que se pode denominar vagamente de tendencias pos-modernas na filosofia, quanto do campo da historia social e da sociologia das ciencias, e as possiveis implicacoes dos mesmos para a pesquisa e a educacao em ciencias. Nossa avaliacao e que, independentemente do problematico de alguns de seus pressupostos, estas correntes tem a contribuir para a nossa compreensao da ciencia e para a formacao de cidadaos mais responsaveis.

Meeting the Challenge: Quantum Physics in Introductory Physics Courses

Teaching quantum theory is a legendary difficult task, not only due to its weirdness, but also because it is philosophically sensitive. Examples from the history and philosophy of science show that one of the main challenges is to find a balanced approach between introducing the most basic quantum concepts while taking into account interpretational issues. Although there is no privileged interpretation for QT, teaching and research about QT must make the interpretational choice used explicit. In addition any introductory course should emphasize the strictly quantum features in order to prevent students from establishing undesirable links with classical concepts. While teaching focused on the mathematical formalism remains a choice, pictures may be exploited, but in this case complementarity should be explicitly and carefully introduced. Finally, we argue that the teaching of QT, maybe more than other areas in physics, must be informed by the history and philosophy of science.

Mecánica cuántica fundamental, una propuesta didáctica

Fundamental quantum mechanics (FQM) is a commented presentation of fundamental experiments and concepts of quantum mechanics, the physical theory of the quantum phenomena domain: superposition principle and quantum entanglement become the cornestone of the theoretical foundation of the quantum description. The formalism of these basic notions, for two-level systems, is presented. Also, the quantum measurement problem is stated through the discussion of the ideas of probability, evolution (dynamics) and measurement. Finally, this theoretical construction is contextualized in emblematic experiments of the quantum domain: the two slit experiment, the Stern-Gerlach experiment and the Mach-Zehnder interferometer, and in technological applications, such as quantum teleportation and quantum cryptography. Besides, the FQM is a pedagogical proposal, formed by six didactic sequences, for high school teachers and students.

Max Planck e os enunciados da segunda lei da termodinâmica

This paper explores aspects of the history of the formulation and the transmission of the second law of thermodynamics. The investigation thus has a dual purpose, on the one hand to analyze the treatment given by Max Planck to the second law of thermodynamics presented in the book Treatise of Thermodynamics, on the other hand to point out in the text of Planck his views on energetics. In addition, we will sample a few textbooks used in undergraduate courses in physics in order to see how the original versions of statements of the second law of thermodynamics are presented in current textbooks, considering that some of them refer to the Planck law when addressing the second law, but do not point out his contributions.

A descoberta do efeito Compton: De uma abordagem semiclássica a uma abordagem quântica

We present the history of the research program on the scattering of X rays by the matter pursued by the American physicist Arthur H. Compton (1892-1962). This work led him to suggest what we call nowadays Compton Effect, a work which granted him the 1927 Physics Nobel Prize. We pay particular attention to the semi-classical models initially used by him and to the context of the influences he received while moving to suggest a quantum approach to the subject.