We begin by surveying the historical positions in different attempts to understand the material world since the rise of modern science, with specific focus on the role of Cartesian primary qualities in explanatory conceptualisation. Moreover the opening chapter argues that although explanatory narratives are essentially epistemological constructions, they require a general metaphysical backing through the explainer's and explainee's commitments to take the concepts and higher structures composed of them as directly referential. Two methodological perspectives on theory construction, Einstein's division into principle and constructive theories, are then delineated along the lines of their metaphysical and explanatory potential, and presented as the research instrument with which to approach the specific-case-study instances of quantum theory reconstruction. A specific strategy of arguing for scientific realism ('the simple transcendental strategy') is then presented and connected to the challenges that the phenomena (EPR correlations and 'teleportation') from the domain of contemporary quantum theory pose for it. The opening chapter concludes with a survey of the general models of explanation and their position with respect to the principle-constructive dichotomy introduced above. Finally, an explanatory model containing extended material-like entities along with further primitives, universal laws of temporal evolution, is argued for. Consequently, in the interest of a wholesome realistic response to the sceptical challenge about the explanatory aims of science, we recommend that even the common sense conceptual framework replaces the extended material structure with 'generalised things' as re-identifiable invariants through change as the fundamental unit of the realist ontology.
We begin by surveying the historical positions in different attempts to understand the material world since the rise of modern science, with specific focus on the role of Cartesian primary qualities in explanatory conceptualisation. Moreover the opening chapter argues that although explanatory narratives are essentially epistemological constructions, they require a general metaphysical backing through the explainer's and explainee's commitments to take the concepts and higher structures composed of them as directly referential. Two methodological perspectives on theory construction, Einstein's division into principle and constructive theories, are then delineated along the lines of their metaphysical and explanatory potential, and presented as the research instrument with which to approach the specific-case-study instances of quantum theory reconstruction. A specific strategy of arguing for scientific realism ('the simple transcendental strategy') is then presented and connected to the challenges that the phenomena (EPR correlations and 'teleportation') from the domain of contemporary quantum theory pose for it. The opening chapter concludes with a survey of the general models of explanation and their position with respect to the principle-constructive dichotomy introduced above. Finally, an explanatory model containing extended material-like entities along with further primitives, universal laws of temporal evolution, is argued for. Consequently, in the interest of a wholesome realistic response to the sceptical challenge about the explanatory aims of science, we recommend that even the common sense conceptual framework replaces the extended material structure with 'generalised things' as re-identifiable invariants through change as the fundamental unit of the realist ontology.
According to scientific realism, science gives us an approximately true description of what the world is like. But what does it mean? In this chapter, we focus on the ontological and metaphysical aspects of this discussion. That is, we are concerned with the following questions: what there is, according to our best scientific theories? And how are these things that theories say exist? We start from the assumption that a genuine scientific realism must deal with these issues. Taking non-relativistic quantum mechanics as a case study, we discuss some of the challenges currently faced by a genuinely realistic stance. We argue, first, that in the ontological aspect, realists are in the same boat as science, that is, without sufficient epistemic justification to adopt the belief in the entities postulated by a single quantum theory, given that experience (currently) is not able to decide between rival theories; in the metaphysical aspect, realists also encounter problems with theory choice, given the possibility of associating more than one metaphysical theory with the description of the entities postulated by each quantum theory. The same goes for structuralist alternatives, since, even if we accept that scientific theories are committed to the existence of structures, but not objects, we still do not know what structures are, metaphysically. Finally, we move forward in the discussion with the meta-Popperian method, which serves to reduce the metaphysical alternatives associated with the ontological postulates of scientific theories. We may not know what the correct alternative is, but we have been able to progressively check which metaphysical alternatives are incompatible with each scientific theory.
What becomes of our clearest theories of explanation, when faced with the unpalatable quantum phenomena that seem to undermine the direct conceptual connection between the fundamental material entities and the self-standing material objects of everyday parlance? The general explanatory theory advocates unification of explanatory concepts with everyday discourse, identification of essentially similar characteristics between direct experience and the hypothesised explanatory ontology, and a conceptualisation of phenomena in terms of objects enduring causally regulated change. On the other hand quantum theory feeds anti-realist suspicions about the worth of (metaphysical) realist explanatory endeavour with examples of phenomena in which the structure of material separation and individuation based on spatial extension is insufficient for construction of deeper explanatory narratives. An example from history of science, that of Newton’s law-constitutive definition of objects in response to Descartes problem of bodies is used to suggest a possible strategy for explanations unifying the quantum and common-sense conceptual domains, provided the anti-realist challenge to such enterprise is read as questioning the epistemological justification of interpretation of experience in both cases. \n(IN CROATIAN: Što se događa s najjasnijim dostupnim teorijama objašnjenja kada se suoče s problematičnim kvantnim pojavama koje naizgled potkopavaju neposrednu konceptualnu poveznicu između fundamentalnih materijalnih entiteta i samoopstojnih materijalnih predmeta iz svakodnevnog govora? Opća teorija objašnjenja preporuča objedinjenje teoretskih eksplanatornih pojmova sa svakodnevnim govorom, određenje esencijalno sličnih karakteristika između neposrednog iskustva i hipotetske eksplanatorne ontologije te konceptualizaciju pojava kroz predmete koji istraju kroz uzročno regulirane promjene. S druge strane, kvantna teorija potkrjepljuje antirealistične sumnje o valjanosti eksplanatornog nastojanja (metafizičkog) realizma primjerima pojava u kojima je struktura materijalne razdvojenosti i individuacije temeljene na prostornoj protežnosti nedovoljna za izgradnju dubljih eksplanatornih narativa. Primjerom iz povijesti znanosti, Newtonovom definicijom predmeta temeljenom na zakonima kao odgovorom na Descartesov problem materijalnih tijela, daje se moguća strategija izgradnje objašnjenja koja objedinjuju kvantne i “zdravorazumske” konceptualne domene, ukoliko se antirealistična kritika te izgradnje u oba slučaja shvati kao propitivanje epistemološkog opravdanja tumačenja iskustva.)
We put forward a possible new interpretation and explanatory framework for quantum theory. The basic hypothesis underlying this new framework is that quantum particles are conceptual entities. More concretely, we propose that quantum particles interact with ordinary matter, nuclei, atoms, molecules, macroscopic material entities, measuring apparatuses,..., in a similar way to how human concepts interact with memory structures, human minds or artificial memories. We analyze the most characteristic aspects of quantum theory, i.e. entanglement and non-locality, interference and superposition, identity and individuality in the light of this new interpretation, and we put forward a specific explanation and understanding of these aspects. The basic hypothesis of our framework gives rise in a natural way to a Heisenberg uncertainty principle which introduces an understanding of the general situation of ‘the one and the many ’ in quantum physics. A specific view on macro and micro different from the common one follows from the basic hypothesis and leads to an analysis of Schrödinger’s Cat paradox and the measurement problem different from the existing ones. We reflect about the influence of this new quantum interpretation and explanatory framework on the global nature and evolutionary aspects of the world and human worldviews, and point out potential explanations for specific situations, such as the generation problem in particle physics, the confinement of quarks and the existence of dark matter. 1
Philosophers of science commonly connect ontology and science, stating that these disciplines maintain a two-way relationship: on the one hand, we can extract ontology from scientific theories; on the other hand, ontology provides the realistic content of our scientific theories. In this article, we will critically examine the process of naturalizing ontology, i.e., confining the work of ontologists merely to the task of pointing out which entities certain theories commit themselves to. We will use non-relativistic quantum mechanics as a case study. We begin by distinguishing two roles for ontology: the first would be characterized by cataloging existing entities according to quantum mechanics; the second would be characterized by establishing more general ontological categories in which existing entities must be classified. We argue that only the first step is available for a naturalistic approach; the second step not being open for determination or anchoring in science. Finally, we also argue that metaphysics is still a step beyond ontology, not contained in either of the two tasks of ontology, being thus even farther from science.
According to scientific realism, science gives us an approximately true description of what the world is like. But what does it mean? In this chapter, we focus on the ontological and metaphysical aspects of this discussion. That is, we are concerned with the following questions: what there is, according to our best scientific theories? And how are these things that theories say exist? We start from the assumption that a genuine scientific realism must deal with these issues. Taking non-relativistic quantum mechanics as a case study, we discuss some of the challenges currently faced by a genuinely realistic stance. We argue, first, that in the ontological aspect, realists are in the same boat as science, that is, without sufficient epistemic justification to adopt the belief in the entities postulated by a single quantum theory, given that experience (currently) is not able to decide between rival theories; in the metaphysical aspect, realists also encounter problems with theory choice, given the possibility of associating more than one metaphysical theory with the description of the entities postulated by each quantum theory. The same goes for structuralist alternatives, since, even if we accept that scientific theories are committed to the existence of structures, but not objects, we still do not know what structures are, metaphysically. Finally, we move forward in the discussion with the meta-Popperian method, which serves to reduce the metaphysical alternatives associated with the ontological postulates of scientific theories. We may not know what the correct alternative is, but we have been able to progressively check which metaphysical alternatives are incompatible with each scientific theory.
Quantum theory describes our universe incredibly successfully. To our classically-inclined brains, however, it is a bizarre description that requires a reimagining of what fundamental reality, or “ontology”, could look like. This thesis examines different ontological features in light of the success of quantum theory, what it requires, and what it rules out. While these investigations are primarily foundational, they also have relevance to quantum information, quantum communication, and experiments on quantum systems. The way that quantum theory describes the state of a system is one of its most unintuitive features. It is natural, therefore, to ask whether a similarly strange description of states is required on an ontological level. This thesis proves that almost all quantum superposition states for d > 3 dimensions must be real—that is, present in the ontology in a well-defined sense. This is a strong requirement which prevents intuitive explanations of the many quantum phenomena which are based on superpositions. A new theorem is also presented showing that quantum theory is incompatible with macro-realist ontologies, where certain physical quantities must always have definite values. This improves on the Leggett-Garg argument, which also aims to prove incompatibility with macro-realism but contains loopholes. Variations on both of these results that are error-tolerant (and therefore amenable to experimentation) are presented, as well as numerous related theorems showing that the ontology of quantum states must be somewhat similar to the quantum states themselves in various specific ways. Extending these same methods to quantum communication, a simple proof is found showing that an exponential number of classical bits are required to communicate a linear number of qubits. That is, classical systems are exponentially bad at storing quantum data. Causal influences are another part of ontology where quantum theory demands a revision of our classical notions. This follows from the outcomes of Bell experiments, as rigorously shown in recent analyses. Here, the task of constructing a native quantum framework for reasoning about causal influences is tackled. This is done by first analysing the simple example of a common cause, from which a quantum version of Reichenbach’s principle is identified. This quantum principle relies on an identification of quantum conditional independence which can be defined in four ways, each naturally generalising a corresponding definition for classical conditional independence. Not only does this allow one to reason about common causes in a quantum experiments, but it can also be generalised to a full framework of quantum causal models (mirroring how classical causal models generalise Reichenbach’s principle). This new definition of quantum causal models is illustrated by examples and strengthened by it’s foundation on a robust quantum Reichenbach’s principle. An unusual, but surprisingly fruitful, setting for considering quantum ontology is found by considering time travel to the past. This provides a testbed for different ontological concepts in quantum theory and new ways to compare classical and quantum frameworks. It is especially useful for comparing computational properties. In particular, time travel introduces non-linearity to quantum theory, which brings (sometimes implicit) ontological assumptions to the fore while introducing strange new abilities. Here, a model for quantum time travel is presented which arguably has fewer objectionable features than previous attempts, while remaining similarly well-motivated. This model is discussed and compared with previous quantum models, as well as with the classical case. Together, these threads of investigation develop a better understanding of how quantum theory affects possible ontologies and how ontological prejudices influence quantum theory.