In this chapter we start with methodological analysis of the notion of scientifictheory and its interrelation with reality. This analysis is based onthe works of Helmholtz, Hertz, Boltzmann, and Schrödinger (and reviewsof D’ Agostino). Following Helmholtz, Hertz established the “Bild concept”for scientific theories. Here “Bild” (“picture”) carries the meaning “model”(mathematical). The main aim of natural sciences is construction of thecausal theoretical models (CTMs) of natural phenomena. Hertz claimed thatCTM cannot be designed solely on the basis of observational data; it typicallycontains hidden quantities. Experimental data can be described by anobservational model (OM), often at the price of acausality. CTM-OM interrelationcan be tricky. Schrödinger used the Bild concept to create CTM forquantum mechanics (QM) and QM was treated as OM. We follow him andsuggest a special CTM for QM, the so-called prequantum classical statisticalfield theory (PCSFT). QM can be considered as a PCSFT-image, but notas straightforward as in Bell’s model with hidden variables. The commoninterpretation of the violation of the Bell inequality is criticized from theperspective of the two-level structuring of scientific theories.
In this chapter we start with methodological analysis of the notion of scientifictheory and its interrelation with reality. This analysis is based onthe works of Helmholtz, Hertz, Boltzmann, and Schrödinger (and reviewsof D’ Agostino). Following Helmholtz, Hertz established the “Bild concept”for scientific theories. Here “Bild” (“picture”) carries the meaning “model”(mathematical). The main aim of natural sciences is construction of thecausal theoretical models (CTMs) of natural phenomena. Hertz claimed thatCTM cannot be designed solely on the basis of observational data; it typicallycontains hidden quantities. Experimental data can be described by anobservational model (OM), often at the price of acausality. CTM-OM interrelationcan be tricky. Schrödinger used the Bild concept to create CTM forquantum mechanics (QM) and QM was treated as OM. We follow him andsuggest a special CTM for QM, the so-called prequantum classical statisticalfield theory (PCSFT). QM can be considered as a PCSFT-image, but notas straightforward as in Bell’s model with hidden variables. The commoninterpretation of the violation of the Bell inequality is criticized from theperspective of the two-level structuring of scientific theories.
We start with a methodological analysis of the notion of scientific theory and its interrelation with reality. This analysis is based on the works of Helmholtz, Hertz, Boltzmann, and Schrödinger (and reviews of D'Agostino). Following Helmholtz, Hertz established the "Bild conception" for scientific theories. Here, "Bild" ("picture") carries the meaning "model" (mathematical). The main aim of natural sciences is construction of the causal theoretical models (CTMs) of natural phenomena. Hertz claimed that a CTM cannot be designed solely on the basis of observational data; it typically contains hidden quantities. Experimental data can be described by an observational model (OM), often based on the price of acausality. CTM-OM interrelation can be tricky. Schrödinger used the Bild concept to create a CTM for quantum mechanics (QM), and QM was treated as OM. We follow him and suggest a special CTM for QM, so-called prequantum classical statistical field theory (PCSFT). QM can be considered as a PCSFT image, but not as straightforward as in Bell's model with hidden variables. The common interpretation of the violation of the Bell inequality is criticized from the perspective of the two-level structuring of scientific theories. Such critical analysis of von Neumann and Bell no-go theorems for hidden variables was performed already by De Broglie (and Lochak) in the 1970s. The Bild approach is applied to the two-level CTM-OM modeling of Brownian motion: the overdamped regime corresponds to OM. In classical mechanics, CTM=OM; on the one hand, this is very convenient; on the other hand, this exceptional coincidence blurred the general CTM-OM structuring of scientific theories. We briefly discuss ontic-epistemic structuring of scientific theories (Primas-Atmanspacher) and its relation to the Bild concept. Interestingly, Atmanspacher as well as Hertz claim that even classical physical theories should be presented on the basic of two-level structuring.
In the nineteenth century (in the process of transition from mechanics to the field theory), the German school of theoretical physics confronted problems similar to the basic problems in the foundations of quantum mechanics (QM). Hertz tried to resolve such problem through analysis of the notion of a scientific theory and interrelation of theory and experiment. This analysis led him to the Bild (image) conception of theory (which was later essentially developed, but also modified by Boltzmann). In this paper, we claim that to resolve the basic foundational problems of QM, one has to use the Bild conception and reject the observational viewpoint on physical theory. As an example of a Bild theory underlying QM (treated as an observational theory), we consider prequantum classical statistical field theory (PCSFT): theory of random subquantum fields.
The interpretation of quantum mechanics remains one of the most challenging problems in the philosophy of science, particularly regarding the relationship between scientific theories and reality. In this section we compare two significant conceptual frameworks that address these challenges: RWR interpretation and the Bild conception of scientific theory structuring. Both approaches offer sophisticated alternatives to traditional realist interpretations while maintaining scientific rigor and explanatory power.
All previous chapters of this book were devoted to the development of the theory of classical (prequantum) random fields reproducing quantum averages (including correlations for entangled systems) as averages of quadratic forms of fields. Since the basic model of prequantum fields is the Gaussian one, these fields are continuous. Hence, in the same way as in the classical signal theory, averages are calculated for variables with a continuous range of values. This model, PCSFT, is really a prequantum model. In accordance with the Bohr’s viewpoint, we consider QM as an operational formalism describing (predicting) results of measurements on microsystems. QM cannot describe intrinsic physical processes in the microworld, but onlymeasurements performed bymacroscopic classical devices. In contrast, PCSFT describes intrinsic processes in the microworld. However, it does not describe results of measurements on the level of individual events, clicks of detectors. As we pointed in Section 1.1.8, in principle one might be satisfied with creation of a prequantum model which reproduces only quantum probabilistic predictions, i.e., without establishing a direct connectionwith theory of measurement on the level of individual events. This approach would match with views of Schro¨dinger and the Bild concept in general. However, historical development of QM demonstrated that the Bild concept was not attractive for the majority of physicists. Since the experimental verification is considered as the basic counterpart of any physical theory, Bild-like prequantum theories are considered as metaphysical. Measurement theory connecting PCSFT with experiment on the level of individual events was developed in my paper [211] (see also Refs. [209, 210, 212, 213]). In this paper I elaborated a scheme of discrete measurements of classical random signals which reproduces the basic rule of QM, the Born’s rule. This is the scheme of threshold-type detection: such a detector clicks after it has “eaten” a special portion of energy
This chapter presents the basics of the mathematical formalism and methodologyof the prequantum classical statistical field theory (PCSFT). In theBild-conception framework, PCSFT gives an example of acausal theoretical model (CTM) beyond QM, considered as observationalmodel (OM). Generally CTM-OM correspondence is not as straightforwardas in Bell’s model with hidden variables. In PCSFT hidden variables are randomfields fluctuating at spatial and temporal scales which are essentiallyfiner than those approached by the present measurement technology. Thekey element of the PCSFT-QM correspondence is mapping of the complexcovariance operator of a subquantum random field to the density operator.For compound systems, the situation is more complicated. Here PCSFT providestwo descriptions of compound systems with random fields valued intensor vs. Cartesian product of the Hilbert spaces of subsystems. The lattermodel matches representation of compound systems in classical statisticalmechanics. Both approaches are used for measure-theoretic representationof the correlations violating the Bell inequalities.
Although, the main objective of this book has been to expose the facts that underpin formal description of quantum mechanics and to make quantum mechanics seem natural, in going about this process we have tried to provide the young student with a guideline on how to approach learning a new theory. Thus, somewhat unconventionally, we start the discourse with a discussion on the meaning of theory and its formal description. This allows us to demonstrate, in concrete terms, how quantum mechanics is just another theoretical framework that conforms to the standard definition of a theory in the natural sciences. In this first chapter, we start with a nontechnical discussion of what one means by a theoretical framework and its formal description. We clarify what qualifies as a theory, and list the questions whose answers one must seek in trying to learn it. A notion of what amounts to understanding a theory is thus conveyed. The meaning of law, axiom, postulate, theorem, falsifiability etc., are thus discussed. We try to draw out the purpose of constructing a formal description of a theory. We also outline the role of abstraction and generalization in its construction. Finally, we discuss the sense in which the terms “philosophy” and “fundamental theorem” are used in the construction of a theoretical framework.