Abstract The emerging field of quantum mereology considers part-whole relations in quantum systems. Entangled quantum systems pose a peculiar problem in the field, since their total states are not reducible to that of their parts. While there exist several established proposals for modelling entangled systems, like monistic holism or relational holism, there is considerable unclarity, which further positions are available. Using the lambda operator and plural logic as formal tools, we review and develop conceivable models and evaluate their consistency and distinctness. The main result is an exhaustive taxonomy of six distinct and precise models that both provide information about the mereological features as well as about the entangled property. The taxonomy is well-suited to serve as the basis for future systematic investigations.
Abstract The emerging field of quantum mereology considers part-whole relations in quantum systems. Entangled quantum systems pose a peculiar problem in the field, since their total states are not reducible to that of their parts. While there exist several established proposals for modelling entangled systems, like monistic holism or relational holism, there is considerable unclarity, which further positions are available. Using the lambda operator and plural logic as formal tools, we review and develop conceivable models and evaluate their consistency and distinctness. The main result is an exhaustive taxonomy of six distinct and precise models that both provide information about the mereological features as well as about the entangled property. The taxonomy is well-suited to serve as the basis for future systematic investigations.
A composite quantum system has properties that are incompatible with every property of its parts. The existence of such global properties incompatible with all local properties constitutes what I call "mereological holism"--the distinctive holism of Quantum Theory. Mereological holism has the dramatic conceptual consequence of making untenable the usual understanding of the "quantum system" as being a "physical object", since composed objects have properties compatible with those of its parts. The notion of "property" can be extended in a unique way to the whole class of operational probabilistic theories (shortly OPTs), of which the most relevant cases are Quantum Theory and Classical Theory. Whereas Classical Theory is not mereologically holistic, we can now search for other OPTs that are so. Within the OPT framework the role of the "system" is that of an input-output connection between two objective events. In non holistic theories, such as Classical Theory, the system can still be regarded as an "object". On the contrary, in holistic theories interpreting "system" as "object" constitutes an hypostatization of a theoretical notion.
Does quantum holism give rise to new forms of abstract holistic semantics? This question can be discussed in the framework of quantum computational logics, non-standard versions of quantum logic that have been suggested by the theory of logical gates in quantum computation. The basic idea of the quantum computational semantics is the following: meanings of sentences are identified with quantum information quantities, represented by pure or mixed states of special quantum systems. In particular cases, the meaning of a sentence may correspond to an entangled state. On this basis, one can formally describe some typical holistic semantic situations, where the meaning of the whole determines the meanings of its parts, but generally not vice versa.
Qualitative representations of mereological structures in Artificial Intelligence are generally based on a set of mutually exclusive and collectively exhaustive crisp (RCC5) relations. The amount of information carried by each element in this set of (crisp) relations is determined by the number of bits (N) required to distinguish all members of the set. This paper posits that mereological vagueness can arise if mereological relations are limited in the amount of information they can carry. Consequently, a comprehensive set of vague mereological relations is introduced, where each relation in this set can only carry 0 < n < N bits of information. In this framework, mereological information is treated as quantum information, with quantum bits (qubits) distinguishing relations subject to ontic vagueness. The main contribution is the thorough examination of mereological relations within a 3 qubit quantum system. Quantum bits are not represented as vectors in a Hilbert space but as cells in (granular) partitions. This paper is the companion to the author's quantized-mereology framework and develops its entangled-state layer: the combination of three simultaneous elementary questions, the families of entangled information states, the probability distribution for possible observations and the dynamics induced by sequences of non-simultaneous questions.
Abstract Quantum mechanics is often said to entail holism—that wholes are more than just the sum of their parts—and hence violate Humean supervenience. Certainly an entangled state cannot readily be interpreted in terms of the properties of the individual particles involved. But there is no clear general argument from quantum mechanics to holism. Still, each of the three major interpretations of quantum mechanics—Bohm, GRW, and many worlds—embodies some form of holism. One might try to rescue Humean supervenience by moving to high-dimensional representation of physical systems, or by constructing a theory with backward-in-time causation, but it is unclear if such strategies will succeed. If holism is accepted, some argue further that there are no individuals at the fundamental physical level: Either relations are fundamental, or the whole universe is fundamental. The arguments for these positions are assessed and found to be wanting.
Concept of quantum entanglement, its role in physics, philosophy, and in updating general worldview are studied in this article. It is pointed out that Schrodinger introduced this concept and some derivatives from it into description of physical reality in the 1935 article in the context of discussion around the Einstein-Podolsky-Rosen thought experiment, but in the related 1936 publication he did not use them. Taking into account the concepts of a mixture and statistical operator, which were introduced by von Neumann and borrowed by Schrödinger, it is shown that the concept of entanglement is not necessary in quantum mechanics unconditionally. At a certain moment of development of the complex quantum systems theory, this concept and its derivatives served as not very successful substitutes for the concepts of a mixture, situation of a mixture. Comparative analysis of some Schrödinger’s, von Neumann’s, and Landau’s theoretical works concludes that imagination of a complex quantum system as a quasi-mechanical aggregate was gradually being overcome; its objective wholeness was being substantiated instead. Therefore, wholeness is inherent not only to quantum phenomena, but also to quantum systems by itself, objectively. By the essence, just the attempt to think this circumstance had brought into life the concept of quantum entanglement. The concept of a mixture and its substitutes – the concepts of entangled state, entanglement, etc. – have not only the scientific but some metaphysical meaning as well: they prove the possibility of rational thinking of wholeness, the reasonableness and effectiveness of rational holism. Therefore, the metaphysics of quantum entanglement in its correct understanding is a manifestation of the rational holism metaphysics. Complete explanation of the Einstein-Podolsky-Rosen thought experiment requires consideration of both these appearances of the quantum wholeness. One can say the essential result of long-term discussion of the EPR experiment is the exhaustive recognition of the quantum reality wholeness. A row of generalizations achieved by A. Alexandrov, I. Tsekhmistro, and D.Bohm are considered. Together with the completed study of the concept of quantum entanglement or Bohr's substantiation of the concept of undivided quantum phenomenon, they support irreducibility of physical reality, the Universe in general to any set of Democritian atoms and their countless combinations, aggregates. All this enriches and improves the understanding of the Universe as a real wholeness. Perhaps, this understanding will be newest substitution for the hitherto popular worldview in the spirit of Democritus.
This paper investigates quantized mereology, which merges quantum information theory with classical mereology, the formal analysis of the part-whole relationship. It emphasizes that information about crisp mereological relations is captured by classical bits, whereas mereological vagueness involves the use of quantum bits, or qubits, to capture mereological information. Transitioning from classical bits to qubits offers a new understanding of part-whole relations among entities that are subject to mereological vagueness. This paper methodically studies the quantized mereology that arises from the classical RCC5 formalism, one of the most widely studied formalisms in Qualitative Reasoning (QR), a subfield of Artificial Intelligence. The argument is made that this method can be extended to quantize more sophisticated QR formalisms, mirroring how strategies are used in physics to transition from classical to quantum systems. The study explores: (i) the conversion of bits to qubits while understanding that these (qu)bits convey mereological information; (ii) the representation of qubit states via set partitions, acknowledging that set theory aligns more closely with classical logic than with the complex vector spaces employed in quantum physics; (iii) demonstrating that classical QR formalisms can be seen as special cases within quantized formalisms; and (iv) showing that qubits more effectively encapsulate information about vague phenomena.