Quantum Mechanical Concepts

Sagar Kumar Biswal

Quantum mechanics is a relatively new branch of physics as compared to the other branches.Many of its concepts are a bit confusing, which is quite obvious, because it completely destroys the classical intuitions of physicists as well as students.But some of its concepts have a classical mechanical analogy and one such concept is the concept of expectation value of observables or operators in quantum mechanics.In a way it is related to the concept of centre of mass in classical mechanics.So, in this paper, first, a review of this concept and its correspondence with centre of mass and later the reason behind the naming of this concept is discussed in brief.

Gerd Christian Krizek

Disputes on the foundations of Quantum Mechanics often involve the conception of reality, without a clear definition on which aspect of this broad concept of reality one refers. We provide an overview of conceptions of reality in classical physics, in philosophy of science and in Quantum Mechanics and its interpretations and analyse their differences and subtleties. Structural realism as conception in philosophy of science will turn out to be a promising candidate to settle old problems regarding the conception of reality in Quantum Mechanics. We amend the analysis of three main interpretations and their relation to structural realism by three well-known informational approaches in the interpretations of Quantum Mechanics. Last we propose an additional class of structural realism supported by QBism.

Rabah Ladj, Mustapha Oldache, Chams-Eddine Khiari +1 more

Through many years of teaching Quantum Mechanics in Algerian universities, we have noticed that students face great obstacles in understanding the meaning of the basic concepts of this theory, such as the Wave Function, the Uncertainly Principle, the Superposition Principle and the Complementarity Principle. We believe that these obstacles rise due to the influence of basic concepts in Classical Mechanics which students studied for many years before studying Quantum Mechanics. For example, in Classical Mechanics, the concept of wave and the concept of corpuscle refer to different things, while in Quantum Mechanics both concepts refer to the same thing, namely a "quantum particle". In order to study the problem, a questionnaire sheet was presented to concerned students third-year (undergraduate physics students) before they studied the subject and after studying it. We note that these third-year students had had, as an introduction, a deep discussion of the meaning of quantum mechanical concepts for about one hour and a half a week during one month. To compare the results and show the importance of the epistemological and educational aspects, we presented again the same questionnaire to fifth-year physics students (B.Sc degree). We mention that the latter learned Quantum Mechanics without an epistemological introduction of the basic quantum mechanical concepts. Before giving our epistemological and didactical analysis of the results, we give a brief review of a previous didactical study related to the subject made by other authors. We conclude by giving some suggestions which we think are necessary in teaching Quantum Mechanics.

Martin Pieper