Various Theories of Reality in Physics

Romàn R. Zapatrin

The ubiquitous nature of modern Information Retrieval and Virtual World give rise to new realities. To what extent are these "realities" real? Which "physics" should be applied to quantitatively describe them? In this essay I dwell on few examples. The first is Adaptive neural networks, which are not networks and not neural, but still provide service similar to classical ANNs in extended fashion. The second is the emergence of objects looking like Einsteinian spacetime, which describe the behavior of an Internet surfer like geodesic motion. The third is the demonstration of nonclassical and even stronger-than-quantum probabilities in Information Retrieval, their use. Immense operable datasets provide new operationalistic environments, which become to greater and greater extent "realities". In this essay, I consider the overall Information Retrieval process as an objective physical process, representing it according to Melucci metaphor in terms of physical-like experiments. Various semantic environments are treated as analogs of various realities. The readers' attention is drawn to topos approach to physical theories, which provides a natural conceptual and technical framework to cope with the new emerging realities.

W. F. G. Swann

Fritz Rohrlich

Nicholas Rescher

The problem of Schrödinger’s Cat has figured prominently in the debates about the bearing of quantum physics on our understanding of physical reality. On its basis, various theorists have maintained the quantum physical world exhibits a probabilistically indecisive physical reality. The analysis of the paper that this appeal to quantum reality is methodologically at odds with and disjoint from its underlying approach to quantum theory itself. If there is to be methodological uniformity at this juncture it will have to be along the lines that Einstein always focused—an incomplete hidden factor (perhaps better than “hidden variables”) approach.

Bernard d’Espagnat

C. S. Unnikrishnan

This chapter examines the nature of physical reality in the context of unavoidable unobservables in physics. One of the features of science, especially physical science, is a powerful urge to construct theories of phenomena, instead of just cataloging and classifying phenomena and their spatio-temporal patterns. The concept of fields' of various kinds dominates physical theory and modern physics, and fields are essential to both classical and quantum theories. The concept of physical reality in the context of the Einstein, Podolsky and Rosen (EPR) assertion of the incompleteness of quantum mechanics is perhaps appropriate. Quantum theory of physical systems consisting of large number of particles led to the concept of a quantum field associated with the particles, a generalisation of the wave function itself. Space and time are supreme and primary unobservables in physics, without any reality independent of matter, notwithstanding their modern status as the dynamical arena of gravitational effects as described in Einstein's general theory of relativity.