It is increasingly suggested that shortages in the supply chain for human blood could be met by the development of techniques to manufacture human blood ex vivo. These techniques fall broadly under the umbrella of synthetic biology. We examine the biopolitical context surrounding the ex vivo culture of red blood cells through the linked concepts of alienation, immunity, bio-value and biosecuritization. We engage with diverse meanings of synthetic blood, and questions about how the discourses of biosecurity and privatization of risk (...) are linked to claims that the technology will address unmet needs and promote social justice. Through our discussion we contrast communitarian ideas that culturing red blood cells ‘extends the gift’ of adult blood donation with understandings of the immunitary logics that underpin the cord-blood economy. (shrink)

David Lewis is a natural target for those who believe that findings in quantum physics threaten the tenability of traditional metaphysical reductionism. Such philosophers point to allegedly holistic entities they take both to be the subjects of some claims of quantum mechanics and to be incompatible with Lewisian metaphysics. According to one popular argument, the non-separability argument from quantum entanglement, any realist interpretation of quantum theory is straightforwardly inconsistent with the reductive conviction that the complete physical state of the world (...) supervenes on the intrinsic properties of and spatio-temporal relations between its point-sized constituents. Here I defend Lewis's metaphysical doctrine, and traditional reductionism more generally, against this alleged threat from quantum holism. After presenting the non-separability argument from entanglement, I show that Bohmian mechanics, an interpretation of quantum mechanics explicitly recognized as a realist one by proponents of the non-separability argument, plausibly rejects a key premise of that argument. Another holistic worry for Humeanism persists, however, the trouble being the apparently holistic character of the Bohmian pilot wave. I present a Humean strategy for addressing the holistic threat from the pilot wave by drawing on resources from the Humean best system account of laws. (shrink)

Distance, it is often argued, is the only coherent and empirically adequate world-making relation that can glue together the elements of the world. This paper offers entanglement as an alternative world-making relation. Entanglement is interesting since it is consistent even with quantum gravity theories that do not feature space at the fundamental level. The paper thereby defends the metaphysical salience of such non-spatial theories. An account of distance is the predominant problem of empirical adequacy facing entanglement as a world-making relation. (...) A resolution of this obstacle utilizes insights from the Ryu–Takayanagi formula and Susskind and Maldacena’s related ER = EPR conjecture. Together these indicate how distance can be recovered from entanglement and thus carves the way for entanglement fundamentalism. (shrink)

"In Entangled Empathy, scholar and activist Lori Gruen argues that rather than focusing on animal rights, we ought to work to make our relationships with animals right by empathetically responding to their needs, interests, desires, vulnerabilities, hopes, and unique perspectives. Pointing out that we are already entangled in complex and life-altering relationships with other animals, Gruen guides readers through a new way of thinking about and practicing animal ethics. Lori Gruen is Professor of Philosophy and Coordinator of Wesleyan Animal Studies (...) at Wesleyan University. She is the author of Ethics and Animals and co-editor, with Carol Adams, of Ecofeminism: Feminist Intersections with Animals and the Earth."--Back cover. (shrink)

In The Entanglement, philosopher Alva Noë explores the inseparability of life, art, and philosophy, and argues that we have radically underestimated the significance of this long recognized but underappreciated reality, what he refers to as the "entanglement." The core of The Entanglement is the idea that human existence is inextricably aesthetic and philosophical. In the first half of the book, Noë offers a detailed examination of pictures and seeing, writing and speech, and choreography and dancing, which serve as case studies (...) and the base in which the phenomenon of entanglement is set. In later chapters, Noë deepens this analysis by exploring the nature of the aesthetic itself, and its place in our lives, examining what the entanglement can teach us about science, and, in particular, the project of applying science in the domain of the human. In these later chapters he covers a range of topics, including sex, gender, and the body, psychology and AI, the problem of style, and the nature of 'nature.' Drawing on his work in perception, consciousness, and the philosophy of art, Noë offers a new model for thinking about the nature of the human, the limits to what a natural science of the human can do on its own, and the irreplaceable importance of art and philosophy for the larger project of studying and understanding ourselves. (shrink)

Quantum mechanics tells us that states involving indistinguishable fermions must be antisymmetrized. This is often taken to mean that indistinguishable fermions are always entangled. We consider several notions of entanglement and argue that on the best of them, indistinguishable fermions are not always entangled. We also present a simple but unconventional way of representing fermionic states that allows us to maintain a link between entanglement and non-factorizability.

This paper aims to characterise properly entanglement as an external relation obtaining between multiple quantum degrees of freedom. In particular, we argue that the entanglement relation is a unique relation fully characterised by mutual information, i.e. a quantity standardly used as a measure of entanglement. This analysis leads us to propose a new metaphysical account of entanglement, which we call Relational Entanglement Tesseract. Such an account characterises entanglement for both bipartite and multipartite cases, and, at the same time, it satisfies (...) what we argue are three important desiderata of any metaphysical account of entanglement. (shrink)

Quantum entanglement poses a challenge to the traditional metaphysical view that an extrinsic property of an object is determined by its intrinsic properties. So structural realists might be tempted to cite quantum entanglement as evidence for structural realism. I argue, however, that quantum entanglement undermines structural realism. If we classify two entangled electrons as a single system, we can say that their spin properties are intrinsic properties of the system, and that we can have knowledge about these intrinsic properties. Specifically, (...) we can know that the parts of the system are entangled and spatially separated from each other. In addition, the concept of supervenience neither illuminates quantum entanglement nor helps structural realism. (shrink)

Modernity is better defined as a time orientation, instead of as a set of institutions, which usually smuggles in some provincial or other aprioristic assumptions. A time conception of modernity also gives a precise meaning to postmodernity. Modernity in this non-Eurocentric sense, entails several different, competing master narratives, different social forces of, and conflicts between, modernity and anti-modernity, and different cultural contextualizations of the past-future contrast. But these different varieties do not simply coexist and challenge each other, they are entangled (...) with each other in various ways. Starting from observing how different time warps were interwoven in vanguard modernist art, an analytical framework for grasping, understanding, and explaining the entanglement of modernities is spelled out. (shrink)

While entanglement is a phenomenon discussed in quantum theory, it can also be found in art. We propose to connect entanglement to art’s most fundamental question: what is creativity? For example, Marcel Duchamp found the essence of the creative act in the “art coefficient,” the difference and/or gap between the artist’s intention and realization which is created. This paper locates the common sense understanding of entanglement in an inseparable whole that ensures difference between the intention and realization. Seeing the artistic (...) act as actively designing entanglement within artistic production, we present examples of this from the work of the Japanese-style painter Nakamura, and present a concrete vision for an answer regarding the question of the nature of creativity. (shrink)

A 2015 experiment by Hanson and Delft colleagues provided further confirmation that the quantum world violates the Bell inequalities, being the first Bell test to close two known experimental loopholes simultaneously. The experiment was also taken to provide new evidence of ‘spooky action at a distance’. Here we argue for caution about the latter claim. The Delft experiment relies on entanglement swapping, and our main claim is that this geometry introduces an additional loophole in the argument from violation of the (...) Bell inequalities to action at a distance: the apparent action at a distance may be an artifact of ‘collider bias’. In the absence of retrocausality, the sensitivity of such experiments to this ‘Collider Loophole’ depends on the temporal relation between the entanglement swapping measurement C and the two measurements A and B between which we seek to infer a causal connection. CL looms large if the C is in the future of A and B, but not if C is in the past. The Delft experiment itself is the intermediate case, in which the separation is spacelike. We argue that this leaves it vulnerable to CL, unable to establish conclusively that it avoids it. (shrink)

Entanglement has long been the subject of discussion by philosophers of quantum theory, and has recently come to play an essential role for physicists in their development of quantum information theory. In this paper we show how the formalism of algebraic quantum field theory (AQFT) provides a rigorous framework within which to analyse entanglement in the context of a fully relativistic formulation of quantum theory. What emerges from the analysis are new practical and theoretical limitations on an experimenter's ability to (...) perform operations on a field in one spacetime region that can disentangle its state from the state of the field in other spacelike-separated regions. These limitations show just how deeply entrenched entanglement is in relativistic quantum field theory, and yield a fresh perspective on the ways in which the theory differs conceptually from both standard non-relativistic quantum theory and classical relativistic field theory. (shrink)

Squashed entanglement :829–840, 2004) is a monogamous entanglement measure, which implies that highly extendible states have small value of the squashed entanglement. Here, invoking a recent inequality for the quantum conditional mutual information :575–611, 2015) greatly extended and simplified in various work since, we show the converse, that a small value of squashed entanglement implies that the state is close to a highly extendible state. As a corollary, we establish an alternative proof of the faithfulness of squashed entanglement. We briefly (...) discuss the previous and subsequent history of the Fawzi–Renner bound and related conjectures, and close by advertising a potentially far-reaching generalization to universal and functorial recovery maps for the monotonicity of the relative entropy. (shrink)

This paper argues for a metaphysics of relations based on a characterization of quantum entanglement in terms of non-separability, thereby regarding entanglement as a sort of holism. By contrast to a radical metaphysics of relations, the position set out in this paper recognizes things that stand in the relations, but claims that, as far as the relations are concerned, there is no need for these things to have qualitative intrinsic properties underlying the relations. This position thus opposes a metaphysics of (...) individual things that are characterized by intrinsic properties. A principal problem of the latter position is that it seems that we cannot gain any knowledge of these properties insofar as they are intrinsic. Against this background, the rationale behind a metaphysics of relations is to avoid a gap between epistemology and metaphysics. (shrink)

Quantum entanglement is a key resource, which grants quantum systems the ability to accomplish tasks that are classically impossible. Here, we apply Feynman's sum-over-histories formalism to interacting bipartite quantum systems and introduce entanglement measures for bipartite quantum histories. Based on the Schmidt decomposition of the matrix comprised of the Feynman propagator complex coefficients, we prove that bipartite quantum histories are entangled if and only if the Schmidt rank of this matrix is larger than 1. The proposed approach highlights the utility (...) of using a separable basis for constructing the bipartite quantum histories and allows for quantification of their entanglement from the complete set of experimentally measured sequential weak values. We then illustrate the nonclassical nature of entangled histories with the use of Hardy's overlapping interferometers and explain why local hidden variable theories are unable to correctly reproduce all observable quantum outcomes. Our theoretical results elucidate how the composite tensor product structure of multipartite quantum systems is naturally extended across time and clarify the difference between quantum histories viewed as projection operators in the history Hilbert space and those viewed as chain operators and propagators in the standard Hilbert space. (shrink)

The Entanglement: How Art and Philosophy Make Us What We AreNoëAlvaPrinceton University Press, 2023. pp. 271. £22.00 (HBK).

How much of philosophical, scientific, and political thought is caught up with the idea of continuity? What if it were otherwise? This paper experiments with the disruption of continuity. The reader is invited to participate in a performance of spacetime (re)configurings that are more akin to how electrons experience the world than any journey narrated though rhetorical forms that presume actors move along trajectories across a stage of spacetime (often called history). The electron is here invoked as our host, an (...) interesting body to inhabit (not in order to inspire contemplation of flat-footed analogies between ‘macro’ and ‘micro’ worlds, concepts that already presume a given spatial scale), but a way of thinking with and through dis/continuity – a dis/orienting experience of the dis/jointedness of time and space, entanglements of here and there, now and then, that is, a ghostly sense of dis/continuity, a quantum dis/continuity. There is no overarching sense of temporality, of continuity, in place. Each scene diffracts various temporalities within and across the field of spacetimemattering. Scenes never rest, but are reconfigured within, dispersed across, and threaded through one another. The hope is that what comes across in this dis/jointed movement is a felt sense of différance, of intra-activity, of agential separability – differentiatings that cut together/apart – that is the hauntological nature of quantum entanglements. (shrink)

Entangled states provide the necessary tools for conceptual tests of quantum mechanics and other alternative theories. These tests include local hidden variables theories, pre- and postselective quantum mechanics, QND measurements, complementarity, and tests of quantum mechanics itself against, e.g., the so-called causal communication constraint. We show how to produce various nonlocal entangled states of multiple cavity fields that are useful for these tests, using cavity QED techniques. First, we discuss the generation of the Bell basis states in two entangled cavities, (...) when there is at most one photon in either of the cavities, and then a straightforward generalization to similar N-cavity states. We then show how to produce a nonlocal entangled state when there is precisely one photon hiding in three cavities. These states can be produced by sending appropriately prepared atoms through the cavities. As applications we briefly review two proposals: one to test quantum mechanics against the causal communication constraint using a two-cavity entangled state and the other to test pre- and postselective quantum mechanics using a three-cavity entangled state. The outcome of the latter experiment can be discussed from the viewpoint of the consistent histories interpretation of quantum mechanics and therefore provides an opportunity to subject quantum cosmological ideas to laboratory tests. Finally, we point out the relation between these schemes and the schemes suggested for quantum computing, teleportation, and quantum copying. (shrink)

In this brief paper, we argue about the relationship between quantum entanglement and non-locality.

We explore the entanglement of the vacuum of a relativistic field by letting a pair of causally disconnected probes interact with the field. We find that, even when the probes are initially non-entangled, they can wind up to a final entangled state. This shows that entanglement persists between disconnected regions in the vacuum. However the probe entanglement, unlike correlations, vanishes once the regions become sufficiently separated. The relation between entropy, correlations and entanglement is discussed.

Initially Einstein, Podolsky, and Rosen (EPR) and later Bell shed light on the non-local properties exhibited by subsystems in quantum mechanics. Separately, Kochen and Specker analyzed sets of measurements of compatible observables and found that a consistent coexistence of these results is impossible, i.e., quantum indefiniteness of measurement results. As a consequence, quantum contextuality, a more general concept compared to non-locality, leads to striking phenomena predicted by quantum theory. Here, we report neutron interferometric experiments which investigate entangled states in a (...) single-particle system: entanglement is, in this case, achieved not between particles, but between degrees of freedom i.e., between spin, path, and energy degrees of freedom. Appropriate combinations of the spin analysis and the position of the phase shifter in the interferometer allow an experimental verification of the violation of a Bell-like inequality. In addition, state tomography, tomographic analysis of the density matrix of a quantum system, and Kochen-Specker-like phenomena are presented to characterize neutrons’ entangled states and their peculiarity. Furthermore, a coherent energy manipulation scheme is accomplished with a radio-frequency (RF) spin-flipper. This scheme allows the (total) energy degree of freedom to be entangled: the remarkable behavior of a triply entangled GHZ-like state is demonstrated. (shrink)

We show that data collected from corpuses of documents violate the Clauser-Horne-Shimony-Holt version of Bell’s inequality and therefore indicate the presence of quantum entanglement in their structure. We obtain this result by considering two concepts and their combination and coincidence operations consisting of searches of co-occurrences of exemplars of these concepts in specific corpuses of documents. Measuring the frequencies of these co-occurrences and calculating the relative frequencies as approximate probabilities entering in the CHSH inequality, we obtain manifest violations of the (...) latter for all considered corpuses of documents. In comparing these violations with those analogously obtained in an earlier work for the same combined concepts in psychological coincidence experiments with human participants, also violating the CHSH inequality, we identify the entanglement as being carried by the meaning connection between the two considered concepts within the combination they form. We explain the stronger violation for the corpuses of documents, as compared to the violation in the psychology experiments, as being due to the superior meaning domain of the human mind and, on the other side, to the latter reaching a broader domain of meaning and being possibly also actively influenced during the experimentation. We mention some of the issues to be analyzed in future work such as the violations of the CHSH inequality being larger than the ‘Cirel’son bound’ for all of the considered corpuses of documents. (shrink)

Entanglement was initially thought by some to be an oddity restricted to the realm of thought experiments. However, Bell’s inequality delimiting local - behavior and the experimental demonstration of its violation more than 25 years ago made it entirely clear that non-local properties of pure quantum states are more than an intellectual curiosity. Entanglement and non-locality are now understood to figure prominently in the microphysical world, a realm into which technology is rapidly hurtling. Information theory is also increasingly recognized by (...) physicists and philosophers as intimately related to the foundations of mechanics. The clearest indicator of this relationship is that between quantum information and entanglement. To some degree, a deep relationship between information and mechanics in the quantum context was already there to be seen upon the introduction by Max Born and Wolfgang Pauli of the idea that the essence of pure quantum states lies in their provision of probabilities regarding the behavior of quantum systems, via what has come to be known as the Born rule. The significance of the relationship between mechanics and information became even clearer with Leo Szilard’s analysis of James Clerk Maxwell’s infamous demon thought experiment. Here, in addition to examining both entanglement and quantum information and their relationship, I endeavor to critically assess the influence of the study of these subjects on the interpretation of quantum theory. (shrink)

In this paper, it is argued that Aristotelian hylomorphism can supply a useful and informative account of composite entities as these are described by physical theory. In particular, a hylomorphic account of quantum entangled systems is defined in detail, and compared to other alternatives currently on offer—in particular, ontic structural realism. In closing, it is suggested that the view of entanglement outlined here meshes well with a recently proposed ‘coherentist’ conception.

Rob Clifton was one of the most brilliant and productive researchers in the foundations and philosophy of quantum theory, who died tragically at the age of 38. Jeremy Butterfield and Hans Halvorson collect fourteen of his finest papers here, drawn from the latter part of his career (1995-2002), all of which combine exciting philosophical discussion with rigorous mathematical results. Many of these papers break wholly new ground, either conceptually or technically. Others resolve a vague controversy intoa precise technical problem, which (...) is then solved; still others solve an open problem that had been in the air for soem time. All of them show scientific and philosophical creativity of a high order, genuinely among the very best work in the field. The papers are grouped into four Parts. First come four papers about the modal interpretation of quantum mechanics. Part II comprises three papers on the foundations of algebraic quantum field theory, with an emphasis on entanglement and nonlocality. The two papers in Part III concern the concept of a particle in relativistic quantum theories. One paper analyses localization; the other analyses the Unruh effect (Rindler quanta) using the algebraic approach to quantum theory. Finally, Part IV contains striking new results about such central issues as complementarity, Bohr's reply to the EPR argument, and no hidden variables theorems; and ends with a philosophical survey of the field of quantum information. The volume includes a full bibliography of Clifton's publications. Quantum Entanglements offers inspiration and substantial reward to graduates and professionals in the foundations of physics, with a background in philosophy, physics, or mathematics. (shrink)

We investigate quantum entanglement of gravitational configurations in 3D AdS gravity using the AdS/cft correspondence. We derive explicit formulas for the holographic entanglement entropy (EE) of the BTZ black hole, conical singularities and regularized AdS3. The leading term in the large temperature expansion of the holographic EE of the BTZ black hole reproduces exactly its Bekenstein-Hawking entropy SBH, whereas the subleading term behaves as ln SBH. We also show that the leading term of the holographic EE for the BTZ black (...) hole can be obtained from the large temperature expansion of the partition function of a broad class of 2D CFTs on the torus. This result indicates that black hole EE is not a fundamental feature of the underlying theory of quantum gravity but emerges when the semiclassical notion of spacetime geometry is used to describe the black hole. (shrink)

Potentiality, Entanglement and Passion-at-a-Distance is a book for theoretical physicists and philosophers of modern physics. It treats a puzzling and provocative aspect of recent quantum physics: the apparent interaction of certain physical events that cannot share any causal connection. These are said to be `entangled' in some way, but an explanation remains elusive. Abner Shimony - to whom the book is dedicated - and others suggest the need to revive the category of what may be seen as a metaphysical potentiality. (...) Abner has described these events without actions to link them as `passion at a distance': not active, but passive. The discussions gathered here are written by a truly remarkable cast of scientists and philosophers and shed new light on the most profound puzzles of our times. (shrink)

In this essay we take the view that too much reality has been afforded to the notion of ‘particles’ and to ‘flow of supercurrent,’ in the superconducting state. Instead we take the original point of view of Josephson that “ It is clear that intuition is of no great help in understanding the supercurrent as a flow of Cooper pairs “ which is more akin to, and in line with, a “telegraphing of amplitudes” approach. With this conception in mind, we (...) examine the results of Jillie et al and Smith et al. of two Josephson junctions connected in series by a superconducting join. We argue that their results can best be understood in terms of the entanglement of current elements via the interfering of amplitudes. We sketch an approach to calculating the current spanning two entangled Josephson junctions, which reduces to the relation for a single junction when the current is set zero in either of the pair, or the entanglement ceases. We speculate that if this interfering of amplitudes was found to persist, after the separation of the junctions in space, there still remaining a connection in their common past, then this would furnish, at least the possibility, of a new means of signalling without wires. Experiments are suggested. (shrink)

The path integral is not typically utilized for analyzing entanglement experiments, in part because there is no standard toolbox for converting an arbitrary experiment into a form allowing a simple sum-over-history calculation. After completing the last portion of this toolbox (a technique for implementing multi-particle measurements in an entangled basis), some interesting 4- and 6-particle experiments are analyzed with this alternate technique. While the joint probabilities of measurement outcomes are always equivalent to conventional quantum mechanics, differences in the calculations motivate (...) a number of foundational insights, concerning nonlocality, retrocausality, and the objectivity of entanglement itself. (shrink)

Entanglement measures quantify the amount of quantum entanglement that is contained in quantum states. Typically, different entanglement measures do not have to be partially ordered. The presence of a definite partial order between two entanglement measures for all quantum states, however, allows for meaningful conceptualization of sensitivity to entanglement, which will be greater for the entanglement measure that produces the larger numerical values. Here, we have investigated the partial order between the normalized versions of four entanglement measures based on Schmidt (...) decomposition of bipartite pure quantum states, namely, concurrence, tangle, entanglement robustness and Schmidt number. We have shown that among those four measures, the concurrence and the Schmidt number have the highest and the lowest sensitivity to quantum entanglement, respectively. Further, we have demonstrated how these measures could be used to track the dynamics of quantum entanglement in a simple quantum toy model composed of two qutrits. Lastly, we have employed state-dependent entanglement statistics to compute measurable correlations between the outcomes of quantum observables in agreement with the uncertainty principle. The presented results could be helpful in quantum applications that require monitoring of the available quantum resources for sharp identification of temporal points of maximal entanglement or system separability. (shrink)

The idea of entangled modernities is best understood as a complement and corrective to that of `multiple modernities': it serves to theorize the global unity and interconnections of modern socio-cultural formations in a non-reductionist and non-functionalist way. But it can also help to highlight complexity and divergence behind the outwardly uniform or parallel patterns of development. This line of thought seems particularly relevant to the history of Communism. The interdependent but divergent trajectories of the two imperial revolutions, Russian and Chinese, (...) exemplify the multiple patterns of entanglement in unusually instructive ways. In both cases, imperial legacies and traditions interacted with modernizing imperatives and geopolitical constraints, as well as with the revolutionary projects proposed as solutions to the imperial crises. The Sino-Soviet entanglement was highly asymmetric; although the Chinese connection seems to have been important at several critical junctures in Soviet history, the impact of the Soviet model on Chinese Communism was incomparably more formative. But the Chinese metamorphoses of the Soviet model deviated from the original in various ways; they were too complex and sometimes too self-destructive to be explained in terms of an adaptive logic. Rather, the transfigurations that took place at various stages - from the beginnings of Chinese Bolshevism to the aberrations of Maoism in power - can be understood as changing patterns of entanglement, combining radicalizing twists to the Soviet model with selective reactivation of Chinese traditions. (shrink)

The theory of psychological hylomorphism has recently been advanced by David Charles as a viable alternative to physicalist and dualist theories of mind. According to Charles, a human or animal is a psycho-physical whole whose mental and physical properties are defined with reference to the whole. This is because it is a hylomorphic composite of matter and form, where the form contains the material principles of the composite in its definition. In this paper, we raise a difficulty concerning the individuation (...) of forms in light of the quantum theory of matter, asking whether the phenomenon of quantum entanglement gives us reason to doubt that the micro-physical properties of a human or animal derive (solely) from the psycho-physical properties of a middle-sized whole. We suggest several ways of amending the theory of psychological hylomorphism to accommodate entanglement, including a proposal by Simpson, in which the cosmos counts as a psycho-physical whole, and a proposal by Koons, in which distinct substances share a ‘group form.’. (shrink)

Within the field of quantum gravity, there is an influential research program developing the connection between quantum entanglement and spatiotemporal distance. Quantum information theory gives us highly refined tools for quantifying quantum entanglement such as the entanglement entropy. Through a series of well-confirmed results, it has been shown how these facts about the entanglement entropy of component systems may be connected to facts about spatiotemporal distance. Physicists are seeing these results as yielding promising methods for better understanding the emergence of (...) (the dynamical) spacetime (of general relativity) from more fundamental quantum theories, and moreover, as promising for the development of a nonperturbative theory of quantum gravity. However, to what extent does the case for the entanglement entropy-distance link provide evidence that spacetime structure is nonfundamental and emergent from nongravitational degrees of freedom? I will show that a closer look at the results lends support only to a weaker conclusion, that the facts about quantum entanglement are constrained by facts about spatiotemporal distance, and not that they are the basis from which facts about spatiotemporal distance emerge. (shrink)

Two quantum Macro-states and their Macroscopic Quantum Superpositions (MQS) localized in two far apart, space-like separated sites can be non-locally correlated by any entangled couple of single-particles having interacted in the past. This novel “Macro-Macro” paradigm is investigated on the basis of a recent study on an entangled Micro-Macro system involving N≈105 particles. Crucial experimental issues as the violation of Bell’s inequalities by the Macro-Macro system are considered.

This paper deals with an (otherwise classical) two-(non-interacting) particle system immersed in a common stochastic zero-point radiation field. The treatment is an extension of the one-particle case for which it has been shown that the quantum properties of the particle emerge from its interaction with the background field under stationary and ergodic conditions. In the present case we show that non-classical correlations—describable only in terms of entanglement—arise between the (nearby) particles whenever both of them resonate to a common frequency of (...) the field. For identical particles the entanglement becomes maximum and must be described by totally (anti)symmetric states. (shrink)

This paper explores some of the consequences of quantum entanglement for the mainstream metaphysician. The basic idea that entanglement has metaphysical consequences in the form of some kind of “holism” is familiar in the philosophy of physics literature, and finds its way into recent metaphysics, in discussions of failure of Humean supervenience, monism and emergence, for example. The principle aim here is to highlight some questions of detail that occur when attempting to make contact with those metaphysical debates as they (...) occur in the metaphysics literature-details that matter less when the aim is just to show that there is some novelty in entanglement, but more when articulating its precise nature. The conclusion is broadly that the differences are not as great as is sometimes supposed between entanglement and more familiar phenomena already accommodated in prominent metaphysical schemes. (shrink)

We consider the concept of entanglement for pure cases of finite dimensional state spaces. The criterion of unentangled states is related to demanding rank one of an associated eigenvalue problem. In addition to the conventional procedure based on the Schmidt decomposition, we devise a method based on the spectral resolution of unsymmetric matrices. In particular, we consider the case when all eigenvalues are zero, and find that the method still works.

The limitation on the sharing of entanglement is a basic feature of quantum theory. For example, if two qubits are completely entangled with each other, neither of them can be at all entangled with any other object. In this paper we show, at least for a certain standard definition of entanglement, that this feature is lost when one replaces the usual complex vector space of quantum states with a real vector space. Moreover, the difference between the two theories is extreme: (...) in the real-vector-space theory, there exist states of arbitrarily many binary objects, “rebits,” in which every rebit in the system is maximally entangled with each of the other rebits. (shrink)

Summary Proposed by Einstein, Podolsky, and Rosen (EPR) in 1935, the entangled state has played a central part in exploring the foundation of quantum mechanics. At the end of the twentieth century, however, some physicists and mathematicians set aside the epistemological debates associated with EPR and turned it from a philosophical puzzle into practical resources for information processing. This paper examines the origin of what is known as quantum information. Scientists had considered making quantum computers and employing entanglement in communications (...) for a long time. But the real breakthrough only occurred in the 1980s when they shifted focus from general-purpose systems such as Turing machines to algorithms and protocols that solved particular problems, including quantum factorization, quantum search, superdense code, and teleportation. Key to their development was two groups of mathematical manipulations and deformations of entanglement—quantum parallelism and ‘feedback EPR’—that served as conceptual templates. The early success of quantum parallelism and feedback EPR was owed to the idealized formalism of entanglement researchers had prepared for philosophical discussions. Yet, such idealization is difficult to hold when the physical implementation of quantum information processors is at stake. A major challenge for today's quantum information scientists and engineers is thus to move from Einstein et al.'s well-defined scenarios into realistic models. (shrink)

Experiments involving delayed-choice entanglement swapping seem to suggest that particles can become entangled after they’ve already been detected. This astonishing result is taken by some to undermine realism about entanglement. In this paper, I argue that one can offer a fully realist explanation of delayed-choice entanglement swapping by countenancing timelike entanglement relations. I argue that such an explanation—radical though it may be—isn’t incoherent and doesn’t invite paradox. I compare this approach to the antirealist alternative and a more deflationary realist strategy (...) defended by Egg, each of which face certain challenges. The upshot is that we should take seriously the possibility of timelike entanglement and seek to develop a framework for quantum theory which allows for it. (shrink)

Entangled states are a specific feature of quantum physics that neither have a counterpart in classical physics nor in the realm of our ordinary experiences. In this chapter we outline the debate about these particular states both historically and systematically. We delineate how the debate originated in an argument for the incompleteness of quantum mechanics by Einstein, Podolsky and Rosen, and we show why, on the one hand, the argument is not considered convincing today, on the other hand, however, still (...) affects present discussions. In a second part we give a systematic overview over the contemporary debate on entanglement which focusses on Bell’s theorem and its consequences. Discerning different levels, we reconstruct the theorem and its premises in a clear way and discuss possible consequences. We analyze in detail the received view that Bell’s theorem implies non-locality and relate it to concepts such as “non-separability‘ and “holism‘. Especially we examine the question whether the phenomena involving entangled systems can be explained causally and whether the central conflict between a non-locality and the theory of relativity can be solved. (shrink)

We argue that in implanted neurotechnology research, participants and researchers experience what Henry Richardson has called “moral entanglement.” Participants partially entrust researchers with access to their brains and thus to information that would otherwise be private, leading to created intimacies and special obligations of beneficence for researchers and research funding agencies. One of these obligations, we argue, is about continued access to beneficial technology once a trial ends. We make the case for moral entanglement in this context through exploration of (...) participants’ vulnerability, uncompensated risks and burdens, depth of relationship with the research team, and dependence on researchers in implanted neurotechnology trials. (shrink)

Delayed-choice entanglement swapping experiments have been argued to undermine realism about entanglement. One response has been to argue that the correlations displayed in delayed-choice entanglement swapping experiments have a different physical interpretation than the correlations in the non-delayed case. This strategy runs into problems when applied to cases of spacelike entanglement swapping, as it would appear to require one to either posit a privileged foliation of spacetime or otherwise accept that whether entanglement obtains is frame dependent. In this article, I (...) present a realist-friendly account of entanglement swapping that circumvents this dilemma, in which entanglement is explicated via the notion of a common ground. The issue of frame dependence is resolved by adopting the past light-cone criterion for property attribution, and the correlations displayed in the spacelike entanglement swapping experiments are attributed to a joint common ground. (shrink)

Technological advancements raise anthropological questions: How do humans differ from technology? Which human capabilities are unique? Is it possible for robots to exhibit consciousness or intelligence, capacities once taken to be exclusively human? Despite the evident need for an anthropological lens in both societal and research contexts, the philosophical anthropology of technology has not been established as a set discipline with a defined set of theories, especially concerning emerging technologies. In this paper, I will utilize a New Materialist approach, focusing (...) particularly on the theories of Donna Haraway and Karen Barad, to explore their potential for an anthropology of technology. I aim to develop a techno-anthropological approach that is informed and enriched by New Materialism. This approach is characterized by its relational perspective, a dynamic and open conception of the human being, attention to diversity and the dynamics of power in knowledge production and ontology, and an emphasis on the non-human. I aim to outline an anthropology of technology centered on New Materialism, wherein the focus, paradoxically, is not exclusively on humans but equally on non-human entities and the entanglement with the non-human. As will become clear, the way we understand humans and their relationship with technology is fundamental for our concepts and theories in ethics of technology. (shrink)

While debate is heating up regarding the development of AI and its perceived impacts on human society, policymaking is struggling to catch up with the demand to exercise some regulatory control over its rapid advancement. This paper aims to introduce the concept of entangled AI that emerged from participatory backcasting research with an AI expert panel. The concept of entanglement has been adapted from quantum physics to effectively capture the envisioned form of artificial intelligence in which a strong interconnectedness between (...) AI, humans, society, and nature is reflected. Entanglement assumes that AI should serve nature, social well-being, justice, and the resilience of this intertwined network simultaneously and promote a dynamic balance among these factors. This approach allows us to understand the pervasive role of this technology and the scope of human agency in its development. The study shows how such concepts seem to transcend the dominant discourses related to expectations, technological determinism, and humanism. An additional aim of this paper is to demonstrate how backcasting can contribute to generating useful understandings of the future of AI and fruitful insights for policymaking. (shrink)

Vicarious responsibility is sometimes analysed by considering the different kinds of agents involved—who is vicariously responsible for the actions of whom? In this paper, I discuss vicarious responsibility from a different angle: in what sense is the vicarious agent responsible? I do this by considering the ways in which one may take responsibility for events caused by another agent or process. I discuss three senses of taking responsibility—accepting fault, assuming obligations, and fulfilling obligations—and the forms of vicarious responsibility that correspond (...) to these. I end by explaining how to judge which sense applies in a given case, based on the degree of (what I call) moral entanglement between the agent and what they should take responsibility for. (shrink)

In this paper I use philosophical accounts on the relationship between trust and knowledge in science to apprehend this relationship on the Web. I argue that trust and knowledge are fundamentally entangled in our epistemic practices. Yet despite this fundamental entanglement, we do not trust blindly. Instead we make use of knowledge to rationally place or withdraw trust. We use knowledge about the sources of epistemic content as well as general background knowledge to assess epistemic claims. Hence, although we may (...) have a default to trust, we remain and should remain epistemically vigilant; we look out and need to look out for signs of insincerity and dishonesty in our attempts to know. A fundamental requirement for such vigilance is transparency: in order to critically assess epistemic agents, content and processes, we need to be able to access and address them. On the Web, this request for transparency becomes particularly pressing if (a) trust is placed in unknown human epistemic agents and (b) if it is placed in non-human agents, such as algorithms. I give examples of the entanglement between knowledge and trust on the Web and draw conclusions about the forms of transparency needed in such systems to support epistemically vigilant behaviour, which empowers users to become responsible and accountable knowers. (shrink)