Questions of Physical Theory

Giridhari Lal Pandit

My main aim here is to present a general methodological principle, which I propose to designate as Heisenberg-Einstein context principle, as it emerges from their dialogue on physical theory, becoming their most important meeting point in the interpretation of quantum mechanics. I regard as context-principles those which can serve as guiding principles in theory-finding and theory-testing within physics. I think that they must be judged by their impact in making physics open-ended. As regards Heisenberg-Einstein dialogue, three important questions can be raised. The first question is which particular aspect of physical theory were they both concerned with. The second question is whether there emerged from their dialogue some general principle, as a guiding principle of sufficient methodological interest, on which they both showed significant agreement, resolving some of their methodological differences by removing some of their shared philosophical misunderstandings concerning physical theory. This gives rise to the third question whether their dialogue resulted in a significant impact on their respective positions on the interpretation, or foundations, of quantum mechanics. While answering the last two questions in the affirmative, I shall argue for the thesis that in their dialogue they shared a rather deep concern with the fundamental aspects of physical theory — with its mathematical formalism. Taken in this aspect, a physical theory, as and when it becomes mature after it has passed tests, contributes to context-building in theory-finding and theory-testing, generating new frontiers of discovery in physics and astronomy. In a nutshell, I am here concerned with the problem of reconnecting observation with theory, and discovery, or rather frontier of discovery, in physics with the core-context of discovery, trying to bring out the significance of the Heisenberg-Einstein context principle.

Arkady Plotnitsky

This article considers a partly philosophical question: What are the ontological and epistemological reasons for using quantum-like models or theories (models and theories based on the mathematical formalism of quantum theory) vs. classical-like ones (based on the mathematics of classical physics), in considering human thinking and decision making? This question is only partly philosophical because it also concerns the scientific understanding of the phenomena considered by the theories that use mathematical models of either type, just as in physics itself, where this question also arises as a physical question. This is because this question is in effect: What are the physical reasons for using, even if not requiring, these types of theories in considering quantum phenomena, which these theories predict fully in accord with the experiment? This is clearly also a physical, rather than only philosophical, question and so is, accordingly, the question of whether one needs classical-like or quantum-like theories or both (just as in physics we use both classical and quantum theories) in considering human thinking in psychology and related fields, such as decision science. It comes as no surprise that many of these reasons are parallel to those that are responsible for the use of QM and QFT in the case of quantum phenomena. Still, the corresponding situations should be understood and justified in terms of the phenomena considered, phenomena defined by human thinking, because there are important differences between these phenomena and quantum phenomena, which this article aims to address. In order to do so, this article will first consider quantum phenomena and quantum theory, before turning to human thinking and decision making, in addressing which it will also discuss two recent quantum-like approaches to human thinking, that by M. G. D'Ariano and F. Faggin and that by A. Khrennikov. Both approaches are ontological in the sense of offering representations, different in character in each approach, of human thinking by the formalism of quantum theory. Whether such a representation, as opposed to only predicting the outcomes of relevant experiments, is possible either in quantum theory or in quantum-like theories of human thinking is one of the questions addressed in this article. The philosophical position adopted in it is that it may not be possible to make this assumption, which, however, is not the same as saying that it is impossible. I designate this view as the reality-without-realism, RWR, view and in considering strictly mental processes as the ideality-without-idealism, IWI, view, in the second case in part following, but also moving beyond, I. Kant's philosophy.

Erkki Brändas

Olga M. Kosheleva, Michael Zakharevich

Many real-life problems are, in general, NP-complete, i.e., informally speaking, are difficult to solve – at least on computers based on the usual physical techniques. A natural question is: can the use of non-standard physics speed up the solution of these problems? This question has been analyzed for several specific physical theories, e.g., for quantum field the-ory, for cosmological solutions with wormholes and/or casual anomalies, etc. However, many physicists believe that no physical theory is perfect, i.e., that no matter how many observations support a physical theory, inevitably, new observations will come which will require this theory to

P. A. M. Dirac