Quantum computing is of high interest because it promises to perform at least some kinds of computations much faster than classical computers. Arute et al. 2019 (informally, “the Google Quantum Team”) report the results of experiments that purport to demonstrate “quantum supremacy” – the claim that the performance of some quantum computers is better than that of classical computers on some problems. Do these results close the debate over quantum supremacy? We argue that (...) they do not. In the following, we provide an overview of the Google Quantum Team’s experiments, then identify some open questions in the quest to demonstrate quantum supremacy. (shrink)

The ideas of quantum simulation and advances in quantum algorithms to solve quantum chemistry problems have been discussed. Theoretical proposals and experimental investigations both have been studied to gauge the extent to which quantum computation has been applied to solve quantum chemical problems till date. The distinctive features and limitations of the application of quantum simulation on chemical systems and current approaches to define and improve upon standard quantum algorithms have been studied in (...) detail. The possibility and consequences of designing an efficient quantum computer that can address chemical problems have been assessed. The experimental realization of quantum supremacy defies the conventional belief of chemists, that millions of qubits would be required to solve fundamental chemistry problems. It is predicted that quantum simulation of quantum chemistry problems will radically revolutionize this field. (shrink)

The rapid pace of development over the last few decades in the domain of machine learning mirrors the advances made in the field of quantum computing. It is natural to ask whether the conventional machine learning algorithms could be optimized using the present-day noisy intermediate-scale quantum technology. There are certain computational limitations while training a machine learning model on a classical computer. Using quantum computation, it is possible to surpass these limitations and carry out such calculations in (...) an optimized manner. This study illustrates the working of the quantum support vector machine classification model which guarantees an exponential speed-up over its typical alternatives. This research uses the quantum SVM model to solve the classification task of a malignant breast cancer diagnosis. This study also demonstrates a comparative analysis of distinct forms of SVM algorithms concerning their time complexity and performances on standard evaluation metrics, namely accuracy, precision, recall, and F1-score, to exemplify the supremacy of quantum SVM over its conventional variants. (shrink)

In settler-colonial Canada, the state does not receive Indigenous testimony as credible evidence. While the state often accepts Indigenous testimony in formal hearings, the state fundamentally rejects Indigenous evidence as a description of the world as it is, as an onto-epistemology. In other words, the Indigenous worldview formation, while it functions as a knowledge system that knows and predicts life, is not admitted to regulatory discussions about effects of resource extraction projects on life. Particularly in such resource-extraction review hearings, partly (...) for obvious reasons of ecological ethics, there is no space for Indigenous relational-ontology. I theorize that beyond racism, white supremacy, and greed, settler-colonial onto-epistemological structures are structured to systematically eliminate the potential for relational-ontologies. This exclusion is complementary to resource-extractivist and legal positivist procedures and is biased against Indigenous knowledge and knowledge-sharing procedures; it is a crisis of state integrity and is philosophically unsound. In my analysis of Canadian National Energy Board documents, I ferret out some of these structures that de facto discredit Indigenous onto-epistemologies; I propose this fundamental problem of the Canadian settler-colonial state must be recognized and changed if the calls of Canada’s Truth and Reconciliation commission are to be met. (shrink)

This book by an internationally reputed Indian scientist traces the developments of Science, Religion and Philosophy in human civilization through the ages. The common underlying bond-more specifically, a linkage of philosophy with both science and religion-has been examined incisively. All the three sub-areas of human culture have been presented from a holistic point of view, and at the same time, stressing some of their irreconcilable basic differences in scope and outlook. Meant primarily for general readers, the book achieves a fine (...) balance between basic comcepts, historical evolution and a critical unbiased analysis of rituals, dogmas, unresolved queries and it leads to an enlightened view of 'humanism', 'Nature', 'Unity of man', need for a new paradigm of social and political order transcending globalization and control of resources of weaker nations by supremacy in global power equation. The book reviews the wisdom of the ancient Hindus, Buddhism, Jainism and of the three semitic religions-Judaism, Christianity and Islam. It presents a concise account of the Indian Vedas, Vedangan, Saddarsana, the two epics and the Bhagavadgita, of the philosophy and science of the Greeks, science and technology of ancient Egypt, Babylonia and China. A valuable special feature is a summary of the status of present-day science, starting with the classical phase, and ending with the developments in the last century comprising the Theory of Relativity, quantum physics, genetics, various aspects of human consciousness, modern astronomy, astrophysics and cosmology. Last but not least, the author critically reviews some of the presentday fashionable discourses on 'science as the best way to reach God' and leads the readers to an appraisal of the on-going researches on the unification of the four fundamental interactions of physical sciences. He ends with the inexorable conclusion that this unification, when fully achieved, would still not strictly identify the unique force as 'God as concieved in different religions. (shrink)

Quantum Non-Locality and Relativity is recognized as the premier philosophical study of Bell's Theorem and its implication for the relativistic account of space and time. Previous editions have been praised for the remarkable clarity of Maudlin's descriptions of both Bell's theorem and his examination of the potential conflict between the theorem and relativity. The third edition of this text has been carefully updated to reflect significant developments, including a new chapter covering important recent work in the foundations of physics. (...) Foremost among these is Roderich Tumiulka's explicit, relativistic theory that can reproduce the quantum mechanical violation of Bell's inequality. The "Free Will Theorem" of John Conway and Simon Kochen is also discussed, as is the status of locality in the Many Worlds interpretation of quantum theory. The book has also been updated to reflect recent results in information theory. The book introduces philosophers to the relevant physics and demonstrates how philosophical analysis can help to resolve some of the problems, and requires no technical background in Physics. All of the physics is presented from first principles, and as much as possible is presented pictorially"--Provided by publisher. (shrink)

Quantum Field Theory (QFT) is the mathematical and conceptual framework for contemporary elementary particle physics. In a rather informal sense QFT is the extension of quantum mechanics (QM), dealing with particles, over to fields, i.e. systems with an infinite number of degrees of freedom. (See the entry on quantum mechanics.) In the last few years QFT has become a more widely discussed topic in philosophy of science, with questions ranging from methodology and semantics to ontology. QFT taken (...) seriously in its metaphysical implications seems to give a picture of the world which is at variance with central classical conceptions of particles and fields, and even with some features of QM. -/- The following sketches how QFT describes fundamental physics and what the status of QFT is among other theories of physics. Since there is a strong emphasis on those aspects of the theory that are particularly important for interpretive inquiries, it does not replace an introduction to QFT as such. One main group of target readers are philosophers who want to get a first impression of some issues that may be of interest for their own work, another target group are physicists who are interested in a philosophical view upon QFT. (shrink)

Empirical adequacy, formal explanation and understanding are distinct goals of science. While no a priori criterion for understanding should be laid down, there may be inherent limitations on the way we are able to understand explanations of physical phenomena. I examine several recent contributions to the exercise of fashioning an explanatory discourse to mold the formal explanation provided by quantum mechanics to our modes of understanding. The question is whether we are capable of truly understanding (or comprehending) quantum (...) phenomena, as opposed to simply accepting the formalism and certain irreducible quantum correlations. The central issue is that of understanding versus merely redefining terms to paper over our ignorance. (shrink)

This monograph identifies the essential characteristics of the objects described by current quantum theory and considers their relationship to space-time. In the process, it explicates the senses in which quantum objects may be consistently considered to have parts of which they may be composed or into which they may be decomposed. The book also demonstrates the degree to which reduction is possible in quantum mechanics, showing it to be related to the objective indefiniteness of quantum properties (...) and the strong non-local correlations that can occur between the physical quantities of quantum subsystems. Careful attention is paid to the relationships among such property correlations, physical causation, probability, and symmetry in quantum theory. In this way, the text identifies and clarifies the conceptual grounds underlying the unique nature of many quantum phenomena. (shrink)

Quantum physics, which offers an explanation of the world on the smallest scale, has fundamental implications that pose a serious challenge to ordinary logic. Particularly counterintuitive is the notion of entanglement, which has been explored for the past 30 years and posits an ubiquitous randomness capable of manifesting itself simultaneously in more than one place. This amazing 'non-locality' is more than just an abstract curiosity or paradox: it has entirely down-to-earth applications in cryptography, serving for example to protect financial (...) information; it also has enabled the demonstration of 'quantum teleportation', whose infinite possibilities even science-fiction writers can scarcely imagine. This delightful and concise exposition does not avoid the deep logical difficulties of quantum physics, but gives the reader the insights needed to appreciate them. From 'Bell's Theorem' to experiments in quantum entanglement, the reader will gain a solid understanding of one of the most fascinating areas of contemporary physics. (shrink)

The search for a quantum theory of the gravitational field is one of the great open problems in theoretical physics. This book presents a self-contained discussion of the concepts, methods and applications that can be expected in such a theory. The two main approaches to its construction - the direct quantisation of Einstein's general theory of relativity and string theory - are covered. Whereas the first attempts to construct a viable theory for the gravitational field alone, string theory assumes (...) that a quantum theory of gravity will be achieved only through a unification of all the interactions. However, both employ the general method of quantisation of constrained systems, which is described together with illustrative examples relevant for quantum gravity. There is a detailed presentation of the main approaches employed in quantum general relativity: path-integral quantisation, the background-field method and canonical quantum gravity in the metric, connection and loop formulations. The discussion of string theory centres around its quantum-gravitational aspects and the comparison with quantum general relativity. Physical applications discussed at length include the quantisation of black holes, quantum cosmology, the indications of a discrete structure of spacetime, and the origin of irreversibility. This book will be of interest to researchers and students working in relativity and gravitation, cosmology, quantum field theory and related topics. It will also be of interest to mathematicians and philosophers of science. (shrink)

Some critical philosophers of race have argued that whiteness can be understood as a technology of affect and that white supremacy is comprised partly of unconscious habits that result in racialized perception. In an effort to deepen our understanding of the affective and bodily dimensions of white supremacy and the ways in which affective habits are socially produced, I look to insights from situated affectivity. Theorists in this field maintain that affective experience is not simply a matter of (...) felt inner states, but rather socially and environmentally embedded and fundamentally relational. Jan Slaby presents the concept of an ‘affective arrangement’ as a way to approach affectivity in terms of relational dynamics unfolding within a particular setting. Applying this concept to the societal level, Paul Schuetze introduces the notion of ‘affective milieu.’ I argue that these notions of ‘affective arrangement’ and ‘affective milieu,’ together with an organicist account of habit, can help to illuminate the workings of white supremacy in the United States. My proposed account highlights the extent to which white supremacy is an affective, bodily phenomenon and how racist habits are formed over the course of learning and ongoing affective engagement, in the context of various social settings. Crucially, these affective habits are fully bound up with habits of appraisal, interpretation, and judgment, and therefore inseparable from how subjects come to see and understand their world. (shrink)

"The Quantum Revelation is mind-blowing." --Sting To say that quantum physics is the greatest scientific discovery of all time is not an exaggeration. In their discovery of the quantum realm, the physics community stumbled upon a genuine multifaceted revelation which can be likened to a profound spiritual treasure--a heretofore undreamed of creative power--hidden within our own mind. Quantum physics unequivocally points out that the study of the universe and the study of consciousness are inseparably linked, which (...) is to say that ultimate progress in the one will be impossible without progress in the other. Einstein declared that what it reveals is so immensely important that "it should be everyone's concern." Yet few of us in the general public truly understand how the game-changing discoveries of the past century not only relate to our day-to-day lives, but also give us insights into the nature of reality and our place within it. Written for readers with no physics background, Paul Levy's latest book, The Quantum Revelation: A Radical Synthesis of Science and Spirituality is for those who have heard that quantum physics is a fascinating subject but don't quite understand how or why. Levy contemplates the deeper philosophical underpinnings of quantum physics, exploring the fundamental questions it provokes: What does it mean that quantum theory has discovered that there is no such thing as "objective reality?" How are we participating--via our consciousness--in creating our experience of a reality that quantum theory itself describes as "dreamlike?" What are the implications for us in our day-to-day lives that--as quantum theory reveals--what we call reality is more like a dream that we had previously imagined? The Quantum Revelation is unique in how it synthesizes science and spirituality so as to reveal and explore the dreamlike nature of reality. It is a book not just for people interested in quantum theory, but for anyone who is interested in waking up and dreaming lucidly, be it in our night dreams or our waking life. (shrink)

It has often been claimed that without drastic conceptual innovations a genuine explanation of quantum interference effects and quantum randomness is impossible. This book concerns Bohmian mechanics, a simple particle theory that is a counterexample to such claims. The gentle introduction and other contributions collected here show how the phenomena of non-relativistic quantum mechanics, from Heisenberg's uncertainty principle to non-commuting observables, emerge from the Bohmian motion of particles, the natural particle motion associated with Schrödinger's equation. This book (...) will be of value to all students and researchers in physics with an interest in the meaning of quantum theory as well as to philosophers of science. (shrink)

This book provides a unique survey displaying the power of Riccati equations to describe reversible and irreversible processes in physics and, in particular, quantum physics. Quantum mechanics is supposedly linear, invariant under time-reversal, conserving energy and, in contrast to classical theories, essentially based on the use of complex quantities. However, on a macroscopic level, processes apparently obey nonlinear irreversible evolution equations and dissipate energy. The Riccati equation, a nonlinear equation that can be linearized, has the potential to link (...) these two worlds when applied to complex quantities. The nonlinearity can provide information about the phase-amplitude correlations of the complex quantities that cannot be obtained from the linearized form. As revealed in this wide ranging treatment, Riccati equations can also be found in many diverse fields of physics from Bose-Einstein-condensates to cosmology. The book will appeal to graduate students and theoretical physicists interested in a consistent mathematical description of physical laws. (shrink)

Rita Floyd’s "The Morality of Security: A Theory of Just Securitization" is an important and insightful book that delineates a theory of just securitization (modified from the jus ad bellum and jus in bello criteria in just war theory) involving three sets of principles governing the just initiation of securitization, just conduct of securitization, and just desecuritization. This book is a much-needed addition to the security studies and just war scholarship. -/- Here, I explore the potential of Floyd’s just securitization (...) theory (JST) to provide insights into the moral justifiability of non-state groups that are not political entities engaging in resistance against forms of structural violence that pose an existential threat to those groups. Using the case study of the Black Lives Matter (BLM) movement and the threat of white supremacy to African Americans as an illustrative example, I argue that structural forms of violence can meet Floyd’s definition of an objective existential threat, justifying the resort to securitization by groups such as BLM. (shrink)

The idea that the dynamical properties of quantum systems are invariably relative to other systems has recently regained currency. Using Relational Quantum Mechanics (RQM) for a case study, this paper calls attention to a question that has been underappreciated in the debate about quantum relativism: the question of whether relativity iterates. Are there absolute facts about the properties one system possesses relative to a specified reference, or is this again a relative matter, and so on? It is (...) argued that RQM (in its best-known form) is committed to what I call the Unrestricted Iteration Principle (UIP), and thus to an infinite regress of relativisations. This principle plays a crucial role in ensuring the communicability and coherence of interaction outcomes across observers. It is, however, shown to be incompatible with the widespread, conservative reading of RQM in terms of relations, instead necessitating the adoption of the more unorthodox notion of perspectival facts. I conclude with some reflections on the current state of play in perspectivist versions of RQM and quantum relativism more generally, underscoring both the need for further conceptual development and the importance of the iteration principle for an accurate cost-benefit analysis of such interpretations. (shrink)

Written for advanced undergraduates, physicists, and historians and philosophers of physics, this book tells the story of the development of our understanding of quantum phenomena through the extraordinary years of the first three decades of the twentieth century. Rather than following the standard axiomatic approach, this book adopts a historical perspective, explaining clearly and authoritatively how pioneers such as Heisenberg, Schrodinger, Pauli and Dirac developed the fundamentals of quantum mechanics and merged them into a coherent theory, and why (...) the mathematical infrastructure of quantum mechanics has to be as complex as it is. The author creates a compelling narrative, providing a remarkable example of how physics and mathematics work in practice. The book encourages an enhanced appreciation of the interaction between mathematics, theory and experiment, helping the reader gain a deeper understanding of the development and content of quantum mechanics than any other text at this level. (shrink)

This is a book about the Hilbert space formulation of quantum mechanics and its measurement theory. It contains a synopsis of what became of the Mathematical Foundations of Quantum Mechanics since von Neumann's classic treatise with this title. Fundamental non-classical features of quantum mechanics-indeterminacy and incompatibility of observables, unavoidable measurement disturbance, entanglement, nonlocality-are explicated and analysed using the tools of operational quantum theory. The book is divided into four parts: 1. Mathematics provides a systematic exposition of (...) the Hilbert space and operator theoretic tools and relevant measure and integration theory leading to the Naimark and Stinespring dilation theorems; 2. Elements develops the basic concepts of quantum mechanics and measurement theory with a focus on the notion of approximate joint measurability; 3. Realisations offers in-depth studies of the fundamental observables of quantum mechanics and some of their measurement implementations; and 4. Foundations discusses a selection of foundational topics (quantum-classical contrast, Bell nonlocality, measurement limitations, measurement problem, operational axioms) from a measurement theoretic perspective. The book is addressed to physicists, mathematicians and philosophers of physics with an interest in the mathematical and conceptual foundations of quantum physics, specifically from the perspective of measurement theory. (shrink)

Is it possible to approach quantum theory in a 'therapeutic' vein that sees its foundational problems as arising from mistaken conceptual presuppositions? The book explores the prospects for this project and, in doing so, discusses such fascinating issues as the nature of quantum states, explanation in quantum theory, and 'quantum non-locality'.

Spacetime functionalism is the view that spacetime is a functional structure implemented by a more fundamental ontology. Lam and Wüthrich have recently argued that spacetime functionalism helps to solve the epistemological problem of empirical coherence in quantum gravity and suggested that it also (dis)solves the hard problem of spacetime, namely the problem of offering a picture consistent with the emergence of spacetime from a non-spatio-temporal structure. First, I will deny that spacetime functionalism solves the hard problem by showing that (...) it comes in various species, each entailing a different attitude towards, or answer to, the hard problem. Second, I will argue that the existence of an explanatory gap, which grounds the hard problem, has not been correctly taken into account in the literature. (shrink)

Quantum gravity poses the problem of merging quantum mechanics and general relativity, the two great conceptual revolutions in the physics of the twentieth century. The loop and spinfoam approach, presented in this book, is one of the leading research programs in the field. The first part of the book discusses the reformulation of the basis of classical and quantum Hamiltonian physics required by general relativity. The second part covers the basic technical research directions. Appendices include a detailed (...) history of the subject of quantum gravity, hard-to-find mathematical material, and a discussion of some philosophical issues raised by the subject. This fascinating text is ideal for graduate students entering the field, as well as researchers already working in quantum gravity. It will also appeal to philosophers and other scholars interested in the nature of space and time. (shrink)

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This work is in the public domain in (...) the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant. (shrink)

Presents a guide to the basics of quantum mechanics and measurement.

Introduction -- Quantum information: basic relevant concepts and applications -- Theory -- Part I. Atomic processes -- Coulombic entanglement: one-step single photoionization of atoms -- Coulombic entanglement: one-step double photoinonization of atoms -- Coulombic entanglement: two-step double photoinonization of atoms -- Fine-structure entanglement: bipartite states of flying particlees with rest mass different from zero -- Bipartite states and flying electronic qubits -- Part II. Molecular processes -- One-step double photoionization of molecules -- Two-step double photoionization of molecules -- Part (...) III. Miscellaneous -- Conclusions and prospectives. (shrink)

Problems with the conceptual foundations of quantum mechanics date back to attempts by Max Born, Niels Bohr, Werner Heisenberg, as well as many others in the 1920s to continue to employ the classical concept of a particle in the context of the quantum world. The experimental observations at the time and the assumption that the classical concept of a particle was to be preserved have led to an enormous literature on the foundations of quantum mechanics and a (...) great deal of confusion then and now among non-physicists and students in any field that involves quantum theory. It is the historical approach to the teaching of quantum mechanics that is at the root of the problem. Spacetime is the arena within which quantum mechanical phenomena take place. For this reason, several Appendices are devoted to the nature of spacetime as well as to topics that can help us understand it such as vacuum fluctuations, the Unruh effect and Hawking radiation. Because of the success of quantum mechanical calculations, those who wish to understand the foundations of the theory are often given the apocryphal advice, "just ignore the issue and calculate". It is hoped that this book will help dispel some of the dismay, frustration, and confusion among those who refuse to take to heart this admonition. (shrink)

Toen de jonge Duitse natuurkundige Werner Heisenberg in 1925 ontdekte dat het gedrag van deeltjes op atomair niveau onbepaalbaar is, ontketende hij een wetenschappelijke revolutie die het moderne wereldbeeld op zijn kop zette. Tot het moment van Heisenbergs ontdekking dachten wetenschappers dat alles meetbaar was en leek het een kwestie van tijd voordat de mens de natuur geheel en al zou hebben doorgrond. Met de quantumfysica, waarvoor Heisenberg de grondslag legde, kwam aan dit optimisme een abrupt einde. Er bleek een (...) kloof te gapen tussen onze waarneming en de dynamiek waar alles uit voortkomt.00In?Quantum, de oerknal en God? onderneemt Maarten van Buuren een filosofische verkenning van de consequenties van Werner Heisenbergs ontdekking. Dat brengt Van Buuren tot een nieuw inzicht over de oorsprong van de dingen.?God is Natuur? stelde Baruch Spinoza in de 17e eeuw, maar met de opkomst van de moderne natuurkunde in de 18e en 19e eeuw raakte de natuur haar goddelijke status kwijt. Volgens Van Buuren keert God dankzij de quantumfysica terug als alomvattende kiemkracht in de Natuur. Het idee dat alle natuurprocessen gehoorzamen aan de wet van afkoeling en verval moet volgens hem worden herzien. Aan afkoeling en verval gaat een dynamische impuls vooraf waaruit alle dingen ontstaan en die de energie levert voor alles wat groeit en bloeit.?Vormkracht? is de motor van het universum.0. (shrink)

Philosophers of quantum mechanics have generally addressed exceedingly simple systems. Laura Ruetsche offers a much-needed study of the interpretation of more complicated systems, and an underexplored family of physical theories, such as quantum field theory and quantum statistical mechanics, showing why they repay philosophical attention. She guides those familiar with the philosophy of ordinary QM into the philosophy of 'QM infinity', by presenting accessible introductions to relevant technical notions and the foundational questions they frame--and then develops and (...) defends answers to some of those questions. Finally, Ruetsche highlights ties between the foundational investigation of QM infinity and philosophy more broadly construed, in particular by using the interpretive problems discussed to motivate new ways to think about the nature of physical possibility and the problem of scientific realism. (shrink)

Quantum feminicity is a term that refers to the intersection of quantum theory, a technological branch of physics, with feminist theory, a social and political movement. Engaging the modal logics of this intersection, the article explores this intersection through one aspect of quantum literacy; that of the quantum splitting of the concept of the temporal narrative. The article examines what are the interdisciplinary convergences of feminist and physics’s respective philosophies. Focussing on the quantum modalities that (...) are being practiced in relation to the situated nature of technological platforms engaged, the article proposes that modelling a quantum feminicity can assist in disengaging modes of sexual difference that are used to gender all kinds of bodies through a countermanding the temporal. Experiences of bodies are considered as experimental modes that provide quantum vectors for feminist actions. (shrink)

Practical quantum computing devices and their applications to AI in particular are presently mostly speculative. Nevertheless, questions about whether this future technology, if achieved, presents any special ethical issues are beginning to take shape. As with any novel technology, one can be reasonably confident that the challenges presented by "quantum AI" will be a mixture of something new and something old. Other commentators (Sevilla & Moreno 2019), have emphasized continuity, arguing that quantum computing does not substantially affect (...) approaches to value alignment methods for AI, although they allow that further questions arise concerning governance and verification of quantum AI applications. In this brief paper, we turn our attention to the problem of identifying as-yet-unknown discontinuities that might result from quantum AI applications. Wise development, introduction, and use of any new technology depends on successfully anticipating new modes of failure for that technology. This requires rigorous efforts to break systems in protected sandboxes, and it must be conducted at all stages of technology design, development, and deployment. Such testing must also be informed by technical expertise but cannot be left solely to experts in the technology because of the history of failures to predict how non-experts will use or adapt to new technologies. This interplay between experts and non-experts may be particularly acute for quantum AI because quantum mechanics is notoriously difficult to understand. (As Richard Feynman quipped, "Anyone who claims to understand quantum mechanics is either lying or crazy.") We will discuss the extent to which the difficulties in understanding the physics underlying quantum computing challenges attempts to anticipate new failure modes that might be introduced in AI applications intended for unsupervised operation in the public sphere. (shrink)

This book provides the first unified overview of the burgeoning research area at the interface between Quantum Foundations and Quantum Information. Topics include: operational alternatives to quantum theory, information-theoretic reconstructions of the quantum formalism, mathematical frameworks for operational theories, and device-independent features of the set of quantum correlations. Powered by the injection of fresh ideas from the field of Quantum Information and Computation, the foundations of Quantum Mechanics are in the midst of a (...) renaissance. The last two decades have seen an explosion of new results and research directions, attracting broad interest in the scientific community. The variety and number of different approaches, however, makes it challenging for a newcomer to obtain a big picture of the field and of its high-level goals. Here, fourteen original contributions from leading experts in the field cover some of the most promising research directions that have emerged in the new wave of quantum foundations. The book is directed at researchers in physics, computer science, and mathematics and would be appropriate as the basis of a graduate course in Quantum Foundations. (shrink)

Physicists have grappled with quantum theory for over a century. They have learned to wring precise answers from the theory's governing equations, and no experiment to date has found compelling evidence to contradict it. Even so, the conceptual apparatus remains stubbornly, famously bizarre. Physicists have tackled these conceptual uncertainties while navigating still larger ones: the rise of fascism, cataclysmic world wars and a new nuclear age, an unsteady Cold War stand-off and its unexpected end. Quantum Legacies introduces readers (...) to physics' still-unfolding quest by treating iconic moments of discovery and debate among well-known figures like Albert Einstein, Erwin Schrödinger, and Stephen Hawking, and many others whose contributions have indelibly shaped our understanding of nature. (shrink)

The basic theme of Popper's philosophy--that something can come from nothing--is related to the present situation in physical theory. Popper carries his investigation right to the center of current debate in quantum physics. He proposes an interpretation of physics--and indeed an entire cosmology--which is realist, conjectural, deductivist and objectivist, anti-positivist, and anti-instrumentalist. He stresses understanding, reminding us that our ignorance grows faster than our conjectural knowledge.

In a quantum universe with a strong arrow of time, we postulate a low-entropy boundary condition to account for the temporal asymmetry. In this paper, I show that the Past Hypothesis also contains enough information to simplify the quantum ontology and define a unique initial condition in such a world. First, I introduce Density Matrix Realism, the thesis that the quantum universe is described by a fundamental density matrix that represents something objective. This stands in sharp contrast (...) to Wave Function Realism, the thesis that the quantum universe is described by a wave function that represents something objective. Second, I suggest that the Past Hypothesis is sufficient to determine a unique and simple density matrix. This is achieved by what I call the Initial Projection Hypothesis: the initial density matrix of the universe is the normalized projection onto the special low-dimensional Hilbert space. Third, because the initial quantum state is unique and simple, we have a strong case for the \emph{Nomological Thesis}: the initial quantum state of the universe is on a par with laws of nature. This new package of ideas has several interesting implications, including on the harmony between statistical mechanics and quantum mechanics, the dynamic unity of the universe and the subsystems, and the alleged conflict between Humean supervenience and quantum entanglement. (shrink)

Metaphysicians should pay attention to quantum mechanics. Why? Not because it provides definitive answers to many metaphysical questions-the theory itself is remarkably silent on the nature of the physical world, and the various interpretations of the theory on offer present conflicting ontological pictures. Rather, quantum mechanics is essential to the metaphysician because it reshapes standard metaphysical debates and opens up unforeseen new metaphysical possibilities. Even if quantum mechanics provides few clear answers, there are good reasons to think (...) that any adequate understanding of the quantum world will result in a radical reshaping of our classical world-view in some way or other. Whatever the world is like at the atomic scale, it is almost certainly not the swarm of particles pushed around by forces that is often presupposed. This book guides readers through the theory of quantum mechanics and its implications for metaphysics in a clear and accessible way. The theory and its various interpretations are presented with a minimum of technicality. The consequences of these interpretations for metaphysical debates concerning realism, indeterminacy, causation, determinism, holism, and individuality are explored in detail, stressing the novel form that the debates take given the empirical facts in the quantum domain. While quantum mechanics may not deliver unconditional pronouncements on these issues, the range of possibilities consistent with our knowledge of the empirical world is relatively small-and each possibility is metaphysically revisionary in some way. This book will appeal to researchers, students, and anybody else interested in how science informs our world-view. (shrink)

In the original formulation of quantum mechanics the existence of a precise border between a microscopic world, governed by quantum mechanics, and a macroscopic world, described by classical mechanics was assumed. Modern theoretical and experimental physics has moved that border several times, carefully investigating its definition and making available to observation larger and larger quantum systems. The present book examines a paradigmatic case of the transition from quantum to classical behavior: A quantum particle is revealed (...) in a tracking chamber as a trajectory obeying the laws of classical mechanics. The authors provide here a purely quantum-mechanical description of this behavior, thus helping to illuminate the nature of the border between the quantum and the classical. (shrink)

First-ever comprehensive introduction to the major new subject of quantum computing and quantum information.

The quantum corrections related to the ideal gas model often considered are those associated to the bosonic or fermionic nature of particles. However, in this work, other kinds of corrections related to the quantum nature of phase space are highlighted. These corrections are introduced as improvements in the expression of the partition function of an ideal gas. Then corrected thermodynamics properties of the ideal gas are deduced. Both the non-relativistic quantum and relativistic quantum cases are considered. (...) It is shown that the corrections in the non-relativistic quantum case may be particularly useful to describe the deviation from the Maxwell–Boltzmann model at low temperature and/or in confined space. These corrections can be considered as including the description of quantum size and shape effects. For the relativistic quantum case, the corrections could be relevant for confined space and when the thermal energy of each particle is comparable to their rest energy. The corrections appear mainly as modifications in the thermodynamic equation of state and in the expressions of the partition function and thermodynamic functions like entropy, internal energy and free energy. Expressions corresponding to the Maxwell–Boltzmann model are shown to be asymptotic limits of the corrected expressions. (shrink)

Judicial review of statutes presupposes the establishment of a clear hierarchical supremacy of the constitution, which can serve as a standard of review, as well as an independent and assertive judiciary. The conditions for such a hierarchical supremacy of the constitution were only partly fulfilled in nineteenth‐century Germany. In addition, the concept of the separation of powers was rejected and the judiciary was in a weak position. Therefore the judicial review of ordinances was slow to develop. The judicial (...) review of statutes began only at the end of the nineteenth century and was restricted to formal review as opposed to a review of the content of statutes. (shrink)

This book studies the foundations of quantum theory through its relationship to classical physics. This idea goes back to the Copenhagen Interpretation (in the original version due to Bohr and Heisenberg), which the author relates to the mathematical formalism of operator algebras originally created by von Neumann. The book therefore includes comprehensive appendices on functional analysis and C*-algebras, as well as a briefer one on logic, category theory, and topos theory. Matters of foundational as well as mathematical interest that (...) are covered in detail include symmetry (and its "spontaneous" breaking), the measurement problem, the Kochen-Specker, Free Will, and Bell Theorems, the Kadison-Singer conjecture, quantization, indistinguishable particles, the quantum theory of large systems, and quantum logic, the latter in connection with the topos approach to quantum theory. This book is Open Access under a CC BY licence. (shrink)

Since it was first published, Quantum Field Theory in a Nutshell has quickly established itself as the most accessible and comprehensive introduction to this profound and deeply fascinating area of theoretical physics. Now in this fully revised and expanded edition, A. Zee covers the latest advances while providing a solid conceptual foundation for students to build on, making this the most up-to-date and modern textbook on quantum field theory available. -/- This expanded edition features several additional chapters, as (...) well as an entirely new section describing recent developments in quantum field theory such as gravitational waves, the helicity spinor formalism, on-shell gluon scattering, recursion relations for amplitudes with complex momenta, and the hidden connection between Yang-Mills theory and Einstein gravity. Zee also provides added exercises, explanations, and examples, as well as detailed appendices, solutions to selected exercises, and suggestions for further reading. (shrink)

This book explains, in simple but accurate terms, how orthodox quantum mechanics works. The author, a distinguished theoretical physicist, shows how this theory, realistically interpreted, assigns an important role to our conscious free choices. Stapp claims that mainstream biology and neuroscience, despite nearly a century of quantum physics, still stick essentially to failed classical precepts in which mental intentions have no effect upon our bodily actions. He shows how quantum mechanics provides a rational basis for a better (...) understanding of this connection, even allowing an explanation of certain phenomena currently held to be "paranormal". These ideas have major implications for our understanding of ourselves and our mental processes, and thus also for the meaningfulness of our lives. (shrink)