What are Quantum Measurements?

2020 ◽  
pp. 63-73
Author(s):  
Gershon Kurizki ◽  
Goren Gordon
Keyword(s):  
Quantum State ◽  
Physical Reality ◽  
Human Mind ◽  
Quantum Measurements ◽  
Projection Operators ◽  
Von Neumann ◽  
Single Location ◽  
Quantum Darwinism ◽  
Wavefunction Collapse

Chapter 4 introduces a great QM mystery: the notion of quantum measurements. Henry is in a superposition of versions localized in several places, but when Eve measures Henry’s position she (as a classical observer) either sees Henry or she does not. Physical reality is made of such measurements. Eve’s measurement projects or collapses Henry’s superposition state to a single location. The meaning of quantum-state or wavefunction “collapse” and the role of the observer have been at the heart of the historical debate concerning the interpretation of QM. Whereas Von Neumann and Wigner stressed the inseparability of the observed (measured) world from the human mind, alternative “observer-free” views were suggested, such as Everett’s many-world interpretation or Zurek’s quantum Darwinism that replaces the observer by the environment. In the appendix to this chapter the notion of probability amplitudes is elucidated, new notations for operators are introduced and projection operators are presented.

scholarly journals Convergence Conditions of Mixed States and their von Neumann Entropy in Continuous Quantum Measurements

2014 ◽  
Vol 21 (04) ◽  
pp. 1450010
Author(s):  
Toru Fuda
Keyword(s):  
Quantum Measurements ◽  
Von Neumann Entropy ◽  
Projection Operators ◽  
Mixed States ◽  
Convergence Conditions ◽  
Von Neumann ◽  
Zeno Effect ◽  
The Difference ◽  
Arbitrary Precision ◽  
Continuous Quantum Measurements

By carrying out appropriate continuous quantum measurements with a family of projection operators, a unitary channel can be approximated in an arbitrary precision in the trace norm sense. In particular, the quantum Zeno effect is described as an application. In the case of an infinite dimension, although the von Neumann entropy is not necessarily continuous, the difference of the entropies between the states, as mentioned above, can be made arbitrarily small under some conditions.

scholarly journals The Invariant Set Postulate: a new geometric framework for the foundations of quantum theory and the role played by gravity

2009 ◽  
Vol 465 (2110) ◽  
pp. 3165-3185 ◽  
Author(s):  
T. N. Palmer
Keyword(s):  
Quantum Theory ◽  
Science Fiction ◽  
State Space ◽  
Fractal Geometry ◽  
Quantum Physics ◽  
Nonlinear Dynamical Systems ◽  
Physical Reality ◽  
Invariant Set ◽  
Geometric Framework

A new law of physics is proposed, defined on the cosmological scale but with significant implications for the microscale. Motivated by nonlinear dynamical systems theory and black-hole thermodynamics, the Invariant Set Postulate proposes that cosmological states of physical reality belong to a non-computable fractal state-space geometry I , invariant under the action of some subordinate deterministic causal dynamics D I . An exploratory analysis is made of a possible causal realistic framework for quantum physics based on key properties of I . For example, sparseness is used to relate generic counterfactual states to points p ∉ I of unreality, thus providing a geometric basis for the essential contextuality of quantum physics and the role of the abstract Hilbert Space in quantum theory. Also, self-similarity, described in a symbolic setting, provides a possible realistic perspective on the essential role of complex numbers and quaternions in quantum theory. A new interpretation is given to the standard ‘mysteries’ of quantum theory: superposition, measurement, non-locality, emergence of classicality and so on. It is proposed that heterogeneities in the fractal geometry of I are manifestations of the phenomenon of gravity. Since quantum theory is inherently blind to the existence of such state-space geometries, the analysis here suggests that attempts to formulate unified theories of physics within a conventional quantum-theoretic framework are misguided, and that a successful quantum theory of gravity should unify the causal non-Euclidean geometry of space–time with the atemporal fractal geometry of state space. The task is not to make sense of the quantum axioms by heaping more structure, more definitions, more science fiction imagery on top of them, but to throw them away wholesale and start afresh. We should be relentless in asking ourselves: From what deep physical principles might we derive this exquisite structure? These principles should be crisp, they should be compelling. They should stir the soul. Chris Fuchs ( Gilder 2008 , p. 335)

On the Origin of Theories: Charles Darwin’s Vocabulary of Method

2017 ◽  
Vol 122 (4) ◽  
pp. 1079-1104 ◽  
Author(s):  
Henry M. Cowles
Keyword(s):  
Scientific Practice ◽  
Natural World ◽  
Human Mind ◽  
Historical Imagination ◽  
Theory Of Evolution ◽  
John Herschel ◽  
Scientific World ◽  
Evolution By Natural Selection ◽  
Selection Of

Abstract This is an essay on the origin of theories. It argues that methodology can do more than shape scientific theories—sometimes, vocabularies of method become such theories. The origin of Charles Darwin’s theory of evolution by natural selection is a case in point: Darwin’s well-known attention to methodological matters not only framed but bled into his theory of nature. A careful student of contemporary methodology, Darwin sought guidance for using a controversial tool in the scientific world in which he came of age: the hypothesis. In the process of reading the works of John Herschel and William Whewell, Darwin turned nature itself into a man of science. The hypotheses and testing of scientific practice were mirrored in the variations and selection of the natural world. Though unintentional, Darwin’s naturalization of a vocabulary of method helped pave the way for applications of evolutionary theory to the study of the human mind and, completing the circle, to the philosophy of science. Considering the role of vocabularies of method in the origin of theories suggests new directions for the study of cognitive history and the power of language to transform the historical imagination.

The Role of Cognitive Patterns in Modelling Reality by Means of Natural Language (The Case Study of the English Cognitive Pattern “Cleanness / Dirtiness”)

2021 ◽  
pp. 69-81
Author(s):  
Ekaterina Savitskaya ◽  
Keyword(s):  
Natural Language ◽  
Cognitive Linguistics ◽  
Human Mind ◽  
Specific Language ◽  
Cognitive Patterns ◽  
Cognitive Pattern ◽  
The World ◽  
Internal Comparison

In the field of cognitive linguistics it is accepted that, before developing its capacity for abstract and theoretical thought, the human mind went through the stage of reflecting reality through concrete images and thus has inherited old cognitive patterns. Even abstract notions of the modern civilization are based on traditional concrete images, and it is all fixed in natural language units. By way of illustration, the author analyzes the cognitive pattern “сleanness / dirtiness” as a constituent part of the English linguoculture, looking at the whole range of its verbal realization and demonstrating its influence on language-based thinking and modeling of reality. Comparing meanings of language units with their inner forms enabled the author to establish the connection between abstract notions and concrete images within cognitive patterns. Using the method of internal comparison and applying the results of etymological reconstruction of language units’ inner form made it possible to see how the world is viewed by representatives of the English linguoculture. Apparently, in the English linguoculture images of cleanness / dirtiness symbolize mainly two thematic areas: that of morality and that of renewal. Since every ethnic group has its own axiological dominants (key values) that determine the expressiveness of verbal invectives, one can draw the conclusion that people perceive and comprehend world fragments through the prism of mental stereo-types fixed in the inner form of language units. Sometimes, in relation to specific language units, a conflict arises between the inner form which retains traditional thinking and a meaning that reflects modern reality. Still, linguoculture is a constantly evolving entity, and its de-velopment entails breaking established stereotypes and creating new ones. Linguistically, the victory of the new over the old is manifested in the “dying out” of the verbal support for pre-vious cognitive patterns, which leads to “reprogramming” (“recoding”) of linguoculture rep-resentatives’ mentality.

scholarly journals Reading a Qubit Quantum State with a Quantum Meter: Time Unfolding of Quantum Darwinism and Quantum Information Flux

2019 ◽  
Vol 26 (04) ◽  
pp. 1950023
Author(s):  
Salvatore Lorenzo ◽  
Mauro Paternostro ◽  
G. Massimo Palma
Keyword(s):  
Quantum Information ◽  
Harmonic Oscillator ◽  
Quantum System ◽  
Quantum State ◽  
Common Theme ◽  
Quantum Harmonic Oscillator ◽  
Collision Model ◽  
Single Qubit ◽  
Quantum Darwinism

Quantum non-Markovianity and quantum Darwinism are two phenomena linked by a common theme: the flux of quantum information between a quantum system and the quantum environment it interacts with. In this work, making use of a quantum collision model, a formalism initiated by Sudarshan and his school, we will analyse the efficiency with which the information about a single qubit gained by a quantum harmonic oscillator, acting as a meter, is transferred to a bosonic environment. We will show how, in some regimes, such quantum information flux is inefficient, leading to the simultaneous emergence of non-Markovian and non-darwinistic behaviours.

scholarly journals INFLUENCE OF COGNITIVE DYSONANCE ON THE FORMATION OF THE LANGUAGE SYSTEM

2019 ◽  
pp. 70-78
Author(s):  
T. Krech ◽  
I. Milyeva
Keyword(s):  
Cognitive Dissonance ◽  
Human Mind ◽  
Communication Process ◽  
Psychological Reality ◽  
Language System ◽  
The Subject ◽  
The Many

The language system is susceptible to the many changes that occur in society and the consciousness of its members. Language units can be motivated by taboos – a phenomenon that causes a person to abandon the use of some language units and replace them with others that are more suitable for this communicative situation. Such a replacement is due to mental rejection, emotional discomfort, in fact, cognitive dissonance, which is born as a result of various objective and subjective factors. The presence in the human mind of a fideistic attitude to the word is a psychological reality. Therefore, the use of replacement words as a result of a certain mental discomfort has become the subject of research not only for linguists, but also for scientists who deal with issues of culture, religion, ethnography, and especially psychology. Some sources that we used to write an article are not so much of a linguistic nature, but rather of a psycholinguistic one. At the same time, scientists note that consciously or unconsciously, but a person always feels a greater role of associative connections between a word and a named subject. The purpose of the article is to study language units motivated by ancient remnants, and to determine the role of euphemisms in the communication process. It is these “soft” expressions that make speech more pleasant, one that protects the psyche and aesthetic feelings of a person.

scholarly journals Entanglement cost of generalised measurements

2003 ◽  
Vol 3 (5) ◽  
pp. 405-422
Author(s):  
R. Jozsa ◽  
M. Koashi ◽  
N. Linden ◽  
S. Popescu ◽  
S. Presnell ◽  
...  
Keyword(s):  
Quantum Measurements ◽  
Great Circle ◽  
Bloch Sphere ◽  
Numerical Techniques ◽  
Bipartite Entanglement ◽  
Von Neumann ◽  
Tensor Product Space ◽  
Large N ◽  
Dimension 2 ◽  
The Cost

Bipartite entanglement is one of the fundamental quantifiable resources of quantum information theory. We propose a new application of this resource to the theory of quantum measurements. According to Naimark's theorem any rank 1 generalised measurement (POVM) M may be represented as a von Neumann measurement in an extended (tensor product) space of the system plus ancilla. By considering a suitable average of the entanglements of these measurement directions and minimising over all Naimark extensions, we define a notion of entanglement cost E_{\min}(M) of M. We give a constructive means of characterising all Naimark extensions of a given POVM. We identify various classes of POVMs with zero and non-zero cost and explicitly characterise all POVMs in 2 dimensions having zero cost. We prove a constant upper bound on the entanglement cost of any POVM in any dimension. Hence the asymptotic entanglement cost (i.e. the large n limit of the cost of n applications of M, divided by n) is zero for all POVMs. The trine measurement is defined by three rank 1 elements, with directions symmetrically placed around a great circle on the Bloch sphere. We give an analytic expression for its entanglement cost. Defining a normalised cost of any $d$-dimensional POVM by E_{\min} (M)/\log_2 d, we show (using a combination of analytic and numerical techniques) that the trine measurement is more costly than any other POVM with d>2, or with d=2 and ancilla dimension 2. This strongly suggests that the trine measurement is the most costly of all POVMs.

Representing the Self Through the Visualization of Personal Data

2021 ◽  
Vol 12 (1) ◽  
pp. 1-12
Author(s):  
Catarina Sampaio ◽  
Luísa Ribas
Keyword(s):  
Digital Media ◽  
Data Visualization ◽  
Personal Data ◽  
Physical Reality ◽  
Digital Footprint ◽  
Identity Based ◽  
The Common ◽  
Project Data ◽  
Visualization Techniques

The representation of identity in digital media does not necessarily have to be conceived on the basis of criteria that mimic physical reality. This article presents a model for representing individual identity, based on the recording of human experience in the form of personal data, as an alternative to the common forms of mimetic portraiture. As such, the authors developed the project Data Self-Portrait that aims to explore the creative possibilities associated with the concept of data portrait. It can be described as a means of representing and expressing identity through the application of data visualization techniques to the domain of portraiture, according to an exploratory design approach, based on visualizing the digital footprint. It thus seeks to develop design proposals for representing identity that respond to the growing dematerialization of human activities and explores the representational and expressive role of data visualization, according to a creative use of computational technologies.

Can Quantum Measurements Prevent Change?

2020 ◽  
pp. 166-184
Author(s):  
Gershon Kurizki ◽  
Goren Gordon
Keyword(s):  
Quantum State ◽  
High Probability ◽  
Quantum Measurements ◽  
Repeated Measurements ◽  
Quantum Zeno Effect ◽  
Initial State ◽  
Zeno Effect

In a strange dream, Henry is coherently transported towards his bride down the aisle. But just as a small portion of him arrives next to her, that portion disappears in a flash of light caused by a snapshot! Henry keeps trying to be united with his bride, but repeated snapshots cause Henry’s collapse to being far away from her. This dream illustrates the quantum Zeno effect (QZE): if a measurement collapses the quantum state with high probability to the initial state, then frequent repeated measurements can almost stop the change of the quantum state. Yet less frequent measurements cause the opposite, anti-Zeno effect (AZE), whereby change or decay increases. Thus, decay is controllable. These effects confirm Zeno’s argument that change is an illusion, as it is up to the observer to prevent or induce it by appropriate observation. The appendix to this chapter explains the QZE for coherent and decay processes.

Diversity and Relationships

2020 ◽  
pp. 114-150
Author(s):  
Mona Sue Weissmark
Keyword(s):  
Sexual Selection ◽  
Social Relations ◽  
Human Mind ◽  
Social Psychological ◽  
Men And Women ◽  
The Social ◽  
Clinical Consequences ◽  
Key Issues ◽  
And Gender

This chapter outlines key issues in scientific literature concerning how evolutionary processes have shaped the human mind. To that end, psychologists have drawn on Charles Darwin’s sexual selection hypothesis, or how males compete for reproduction and the role of female choice in the process. Darwin argued that evolution hinged on the diversity resulting from sexual reproduction. Evolutionary psychologists posit that heterosexual men and women evolved powerful, highly patterned, and universal desires for particular characteristics in a mate. Critics, however, contend that Darwin’s theory of sexual selection was erroneous, in part because his ideas about sexual identity and gender were influenced by the social mores of his elite Victorian upper class. Despite this critique, some researchers argue similarly to Darwin that love is part of human biological makeup. According to their hypotheses, cooperation is the centerpiece of human daily life and social relations. This makes the emotion of love, both romantic and maternal love, a requirement not just for cooperation, but also for the preservation and perpetuation of the species. That said, researchers speculate that encounters with unfamiliar people, coincident with activated neural mechanisms associated with negative judgments, likely inspire avoidance behavior and contribute to emotional barriers. This suggests the need to further study the social, psychological, and clinical consequences of the link between positive and negative emotions.

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