In the same way as the quantum no-cloning theorem and quantum key distribution in two preceding papers, entanglement-assisted quantum teleportation and Grover’s search algorithm are generalized by transferring them to an abstract setting, including usual quantum mechanics as a special case. This again shows that a much more general and abstract access to these quantum mechanical features is possible than commonly thought. A non-classical extension of conditional probability and, particularly, a very special type of state-independent conditional probability are used (...) instead of Hilbert spaces and wavefunctions. (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)

Quantum state teleportation has focused attention on the role of quantum information. Here we examine quantum teleportation through the Bohm interpretation. This interpretation introduced the notion of active information and we show that it is this information that is exchanged during teleportation. We discuss the relation between our notion of active information and the notion of quantum information introduced by Schumacher.

Whilst a straightforward consequence of the formalism of non-relativistic quantum mechanics, the phenomenon of quantum teleportation has given rise to considerable puzzlement. In this paper, the teleportation protocol is reviewed and these puzzles dispelled. It is suggested that they arise from two primary sources: (1) the familiar error of hypostatizing an abstract noun (in this case, ‘information’) and (2) failure to differentiate interpretation dependent from interpretation independent features of quantum mechanics. A subsidiary source of error, the simulation fallacy, (...) is also identified. The resolution presented of the puzzles of teleportation illustrates the benefits of paying due attention to the logical status of ‘information’ as an abstract noun. Introduction The quantum teleportation protocol 2.1 Some information-theoretic aspects of teleportation 2.1.1 Preamble 2.1.2Application to teleportation The puzzles of teleportation Resolving (dissolving) the problem 4.1 The simulation fallacy The teleportation process under different interpretations 5.1 Collapse interpretations:Dirac/von Neumann, GRW 5.2 No collapse and no extra values: Everett 5.3 No collapse, but extra values: Bohm 5.3.1 A note on active information 5.4 Ensemble and statistical viewpoints Concluding remarks. (shrink)

In this paper I want to examine quantum teleportation from a point of view that is different from that normally considered. This will enable us to gain a new perspective into what is involved in the process of teleportation. It is clear that, at least in the case where particles are involved, it is not the particle that is transported, but rather the information contained in the wave function. This idea in itself is not new, but the central (...) question that requires clarification is the nature of this information. This paper provides a new insight into this question. (shrink)

Alternate View Column AV-62 Keywords: quantum nonlocality entangled states recreation communication Published in the December-1993 issue of Analog Science Fiction & Fact Magazine ; This column was written and submitted 5/17/93 and is copyrighted ©1993 by John G. Cramer. All rights reserved. No part may be reproduced in any form without the explicit permission of the author.

A Controlled Not variant of the standard quantum teleportation protocol affords a step-by-step analysis of what is, or can be said to be, achieved in the process in either location. Dominant interpretations of what quantum teleportation consists in and implies are reviewed in this light. Being mindful of the statistical significance of the terms and operations involved, as well as awareness of classical analogies, can help sort out what is specifically quantum-mechanical, and what is not, in so-called (...) class='Hi'>teleportation. What the latter achieves appears to be the transmission, without the involvement of mysterious channels, of what a quantum state encapsulates: the multitiered probabilistic characterization of a given preparation, which might be all we can possibly know about a physical system in a given experimental situation. (shrink)

Entangled states whose Wigner functions are non-negative may be viewed as being accounted for by local hidden variables (LHV). Recently, there were studies of Bell’s inequality violation (BIQV) for such states in conjunction with the well known theorem of Bell that precludes BIQV for theories that have LHV underpinning. We extend these studies to teleportation which is also based on entanglement. We investigate if, to what extent, and under what conditions may teleportation be accounted for via LHV theory. (...) Our study allows us to expose the role of various quantum requirements. These are, e.g., the uncertainty relation among non-commuting operators, and the no-cloning theorem which forces the complete elimination of the teleported state at its initial port. (shrink)

By exhibiting a violation of a novel form of the Bell-CHSH inequality, \.{Z}ukowski has recently established that the quantum correlations exploited in the standard perfect teleportation protocol cannot be recovered by any local hidden variables model. Allowing the quantum channel state in the protocol to be given by any density operator of two spin-1/2 particles, we show that a violation of a generalized form of \.{Z}ukowski's teleportation inequality can only occur if the channel state, considered by itself, violates (...) a Bell-CHSH inequality. On the other hand, although it is sufficient for a teleportation process to have a nonclassical fidelity---defined as a fidelity exceeding $2/3$---that the channel state employed violate a Bell-CHSH inequality, we show that such a violation does \emph{not} imply a violation of \.{Z}ukowski's teleportation inequality or any of its generalizations. The implication does hold, however, if the fidelity of the teleportation exceeds $2/3(1+1/2\sqrt{2})\approx .90$, suggesting the existence of a regime of nonclassical values of the fidelity, less than $.90$, for which the standard teleportation protocol can be modelled by local hidden variables. (shrink)

Every two years Rene Stettler, owner and director of the Neue Galerie in Luzerne, organizes and hosts the Swiss Biennial on Science, Technics + Aesthetics, an international gathering of scientists, philosophers, and artists for the purpose of discussing their views on a topic of general interest. Stettler has done this since 1995, with each conference centred on a thought-provoking topic. The topic of this year's conference focused on consciousness and teleportation. The conference publicity material posited some interesting discussion points: (...) Are there connections between brain functions, mental phenomena, and quantum physics? What does quantum entanglement tell us about ourselves? What role does consciousness play in the universe (or the universe in consciousness)? Will it ever be possible to teleport human bodies over distance? (shrink)

In this paper I introduce a new species of teleportation which I use to evaluate three explanations of information transfer in quantum teleportation. I will argue that two explanations fail to explain the "physical effect" of teleportation. I will also argue that that information transfer, understood as something more than simple qubit transfer, is not necessary for teleportation to occur.

In this paper I introduce a new species of teleportation which I use to evaluate three explanations of information transfer in quantum teleportation. I will argue that two explanations fail to explain the “physical effect” of teleportation. I will also argue that that information transfer, understood as something more than simple qubit transfer, is not necessary for teleportation to occur.

We treat here three apparently uncorrelated topics from the point of view of dense measurement: The EPR paradox, the teleportation process, and Wheeler's delayed-choice experiment (DCE). We begin with the DCE and show, using its unique nature and the histories formalism, that use may ascertain and fix the notion of dense measurement (the Zeno effect). We show here by including the experimenter (observer) as an inherent part of the physical system and using the Aharonov–Vardi notion of dense measurement along (...) a path, that knowledge of certain properties of the incoming system (after a measurement) is equivalent to dense measurement. We reach the same conclusion by discussing the teleportation process, and the EPR paradox from, the same point of view. (shrink)

Quantum Information Theory and the Foundations of Quantum Mechanics is a conceptual analysis of one of the most prominent and exciting new areas of physics, providing the first full-length philosophical treatment of quantum information theory and the questions it raises for our understanding of the quantum world. -/- Beginning from a careful, revisionary, analysis of the concepts of information in the everyday and classical information-theory settings, Christopher G. Timpson argues for an ontologically deflationary account of the nature of quantum information. (...) Against what many have supposed, quantum information can be clearly defined (it is not a primitive or vague notion) but it is not part of the material contents of the world. Timpson's account sheds light on the nature of nonlocality and information flow in the presence of entanglement and, in particular, dissolves puzzles surrounding the remarkable process of quantum teleportation. In addition it permits a clear view of what the ontological and methodological lessons provided by quantum information theory are; lessons which bear on the gripping question of what role a concept like information has to play in fundamental physics. Topics discussed include the slogan 'Information is Physical', the prospects for an informational immaterialism (the view that information rather than matter might fundamentally constitute the world), and the status of the Church-Turing hypothesis in light of quantum computation. -/- With a clear grasp of the concept of information in hand, Timpson turns his attention to the pressing question of whether advances in quantum information theory pave the way for the resolution of the traditional conceptual problems of quantum mechanics: the deep problems which loom over measurement, nonlocality and the general nature of quantum ontology. He marks out a number of common pitfalls to be avoided before analysing in detail some concrete proposals, including the radical quantum Bayesian programme of Caves, Fuchs, and Schack. One central moral which is drawn is that, for all the interest that the quantum information-inspired approaches hold, no cheap resolutions to the traditional problems of quantum mechanics are to be had. (shrink)

A quantum state represents neither properties of a physical system nor anyone’s knowledge of its properties. The important question is not what quantum states represent but how they are used—as informational bridges. Knowing about some physical situations, an agent may assign a quantum state to form expectations about other possible physical situations. Quantum states are objective: only expectations based on correct state assignments are generally reliable. If a quantum state represents anything, it is the objective probabilistic relations between its backing (...) conditions and its advice conditions. This paper offers an account of quantum states and their function as informational bridges, in quantum teleportation and elsewhere. (shrink)

We propose partial measurements as a conceptual tool to understand how to operate with counterfactual claims in quantum physics. Indeed, unlike standard von Neumann measurements, partial measurements can be reversed probabilistically. We first analyze the consequences of this rather unusual feature for the principle of superposition, for the complementarity principle, and for the issue of hidden variables. Then we move on to exploring non-local contexts, by reformulating the EPR paradox, the quantum teleportation experiment, and the entanglement-swapping protocol for the (...) situation in which one uses partial measurements followed by their stochastic reversal. This leads to a number of counter-intuitive results, which are shown to be resolved if we give up the idea of attributing reality to the wavefunction of a single quantum system. (shrink)

We present a toy theory that is based on a simple principle: the number of questions about the physical state of a system that are answered must always be equal to the number that are unanswered in a state of maximal knowledge. Many quantum phenomena are found to have analogues within this toy theory. These include the noncommutativity of measurements, interference, the multiplicity of convex decompositions of a mixed state, the impossibility of discriminating nonorthogonal states, the impossibility of a universal (...) state inverter, the distinction between bipartite and tripartite entanglement, the monogamy of pure entanglement, no cloning, no broadcasting, remote steering, teleportation, entanglement swapping, dense coding, mutually unbiased bases, and many others. The diversity and quality of these analogies is taken as evidence for the view that quantum states are states of incomplete knowledge rather than states of reality. A consideration of the phenomena that the toy theory fails to reproduce, notably, violations of Bell inequalities and the existence of a Kochen-Specker theorem, provides clues for how to proceed with this research program. (shrink)

It is argued that those who accept the psychological criterion of personal identity, such as Parfit and Shoemaker, should accept what I call the 'series' view of a person, according to which a person is a unified aggregate of mental events and states. As well as defending this view against objections, I argue that it allows the psychological theorist to avoid the two lives objection which the 'animalist' theorists have raised against it, an objection which causes great difficulties for the (...) conception of a person that most psychological theorists favour, the constitution view. It is also argued that the series view allows that people can body swap and teleport, which the constitution view—which takes a person to be a physical object (but a distinct physical object from the human being)—has great trouble with. (shrink)

It is argued that those who accept the psychological criterion of personal identity, such as Parfit and Shoemaker, should accept what I call the ‘series’ view of a person, according to which a person is a unified aggregate of mental events and states. As well as defending this view against objections, I argue that it allows the psychological theorist to avoid the two lives objection which the ‘animalist’ theorists have raised against it, an objection which causes great difficulties for the (...) conception of a person that most psychological theorists favour, the constitution view. It is also argued that the series view allows that people can body swap and teleport, which the constitution view–which takes a person to be a physical object (but a distinct physical object from the human being)–has great trouble with. (shrink)

For many physicists quantum theory contains strong conceptual difficulties, while for others the apparent conclusions about the reality of our physical world and the ways in which we discover that reality remain philosophically unacceptable. This book focuses on recent theoretical and experimental developments in the foundations of quantum physics, including topics such as the puzzles and paradoxes which appear when general relativity and quantum mechanics are combined; the emergence of classical properties from quantum mechanics; stochastic electrodynamics; EPR experiments and Bell's (...) Theorem; the consistent histories approach and the problem of datum uniqueness in quantum mechanics; non-local measurements and teleportation of quantum states; quantum non-demolition measurements in optics and matter wave properties observed by neutron, electron and atomic interferometry. Audience: This volume is intended for graduate students of physics and those interested in the foundations of quantum theory. (shrink)

We revisit the EPR problem and make clear what is a correct comprehension of its problem. When one applies the quantum mechanics correctly, it will be shown that there is no paradox. According to these lines of thought, a quantum teleportation scheme without resort to the von Neumann projection postulate is presented.

It is widely believed that the semantic contents of some linguistic and mental representations are determined by factors independent of a person’s bodily makeup. Arguments derived from Hilary Putnam’s seminal Twin Earth thought experiment have been especially influential in establishing that belief. I claim that there is a neglected version of the mind-body relation which undermines those arguments and also excludes the possibility of zombies. It has been neglected because it is counterintuitive but I show that it can nonetheless be (...) intelligibly worked out in detail and all obvious objections met. This suggests that we may be faced with a choice between embracing a counterintuitive interpretation of the mind-body relation or accepting that a currently very promising theory in cognitive science, Prediction Error Minimization, faces a fundamental problem. Furthermore, blocking that threat entails that any physicalist/materialst theory of mind is freed from the spectre of zombie worlds. The proposal also makes the ideas of personal teleportation of mind uploading more plausible. (shrink)

Get the science facts, not science fiction, on the cutting-edge developments that are already changing the course of our future. Every day, scientists conduct pioneering experiments with the potential to transform how we live. Yet it isn’t every day you hear from the scientists themselves! Now, award–winning author Jim Al–Khalili and his team of top-notch experts explain how today’s earthshaking discoveries will shape our world tomorrow—and beyond. Pull back the curtain on: genomics robotics AI the “Internet of Things” synthetic biology (...) transhumanism interstellar travel colonization of the solar system teleportation and much more And find insight into big–picture questions such as: Will we find a cure to all diseases? The answer to climate change? And will bionics one day turn us into superheroes? The scientists in these pages are interested only in the truth—reality-based and speculation-free. The future they conjure is by turns tantalizing and sobering: There’s plenty to look forward to, but also plenty to dread. And undoubtedly the best way to for us to face tomorrow’s greatest challenges is to learn what the future looks like—today. Praise for What the Future Looks Like “A collection of mind-boggling essays that are just the thing for firing up your brain cells.” —Saga Magazine “The predictions and impacts are global... [and] the book contains far more fascinating information than can be covered in this review.” —Choice “This book is filled with essays from experts offering their informed opinions on what the science and technology of today will look like in the future, from smart materials to artificial intelligence to genetic editing.” —Popular Science “Fun is an understatement. This is a great collection to get the summer book season started.” —Forbes.com “The focus on sincere, factual presentation of current and future possibilities by leading experts is particularly welcome in this era of fake news and anti-science rhetoric.” —Library Journal. (shrink)

In this book, Mark P. Fusco offers a historical, philosophical and theological review and appraisal of current research into quantum, post-modern, atheistic, mathematical, and philosophical theories that engage our interpretation of Hans Urs von Balthasar and Ferdinand Ulrich’s accounts of Ur-Kenosis. This cross-disciplinary approach inspires a new speculative metaphysical theory based on the representation of being as a holo-somatic ontology. Holocryptic metaphysics gives us a novel interpretation of transubstantiation as it is founded on the findings of quantum mechanical theory. The (...) quantum object and black hole’s properties present a new way to explain physical matter based on its holographic identity. This scientific theory for representing physical matter’s identity is recognized, for example, in the symmetry existing between a subatomic particle and its orbital shell, a single particle’s identity in relationship to its thermodynamic system, Hawking radiation, and black hole entropy. Further, the properties of quantum non-locality and teleportation signpost a new way to understand the Eternal Logos’ relationship to Jesus Christ and the Eucharist. (shrink)

It is said what it is to persist in time, and on that basis it is shown that time-travel, teleportation, and other mainstays of science fiction are impossible.

Quantum mechanics is certainly a strange place to start an investigation into the nature of the relationship between science and society. However, this article begins by integrating its history and proceeds through current conceptions of it by some physicists to examine quantum mechanics as an intersection of both science and knowledge. A famous thought experiment by Einstein, Podolsky, and Rosen pointed to an area that few physicists still research–a paradigm gone awry. Yet the vast majority of physiciststoday do not agonize (...) over this uncertainty. Physics today presses forward with indominable speed and precision. But by questioning a small sample of physicists doing physics about their practice, this study aims at an everyday physicist’s understanding of the matter; a paradox that lies between the results of experiment and their interpretation or place as knowledge in society. For Einstein, Podolsky, and Rosen, the paradox was that we can only determine the spin of an entangled particle–it only becomes real–after measuring the spin of its partner particle. For a few contemporary physicists, the problem is how to understand the fact that a measured particle “teleports” its state instantaniously to another point in space. Practicing physicist resolve this, to put it simply, by just using it. Quantum mechanics, as with physics, is incredibly accurate–accepting it as truth yields results that physicists and society can use. By interrogating this process in its historicity and current formulation, this article sheds some light on the way physics works as knowledge. It provides a possibility for turning the scientific eye toward the very meaning of science. (shrink)

When Ken Malone investigates a case of something causing mental static across the United States, he is teleported to a world that doesn't exist.

In this paper I consider the problem of interpreting quantum mechanics. I argue that this problem has evolved in part into the problem of selecting tenable interpretations from a set of available interpretations. We lack the means to make this selection. There is consensus that interpretations should be consistent and empirically adequate. But these conditions are not particularly discriminative. Other conditions may be discriminative but are not generally accepted. I propose two new conditions for selecting tenable interpretations, motivated by the (...) use of quantum mechanics in technology. The first requires that interpretations ascribe the physical properties to technical artefacts that are entailed by the ascription of technical functions to those artefacts. The second requires that they ascribe the physical properties represented by engineering sketches of those artefacts. I consider the example of quantum teleportation in some detail. Introduction The problem of interpreting quantum mechanics Technical functions Decoders in quantum teleportation Engineering sketches Conclusions Appendix: Quantum teleportation. (shrink)

Christopher G. Timpson provides the first full-length philosophical treatment of quantum information theory and the questions it raises for our understanding of the quantum world. He argues for an ontologically deflationary account of the nature of quantum information, which is grounded in a revisionary analysis of the concepts of information.

Two recently proposed quantum experiments are analyzed. The first allows to find an object without "touching" it. The second allows to teleport quantum states, transmitting a very small amount of information. It is shown that in the standard approach these experiments are in conflict with the intuitive notions of causality and locality. It is argued that the situation is less paradoxical in the framework of the many-worlds interpretation of quantum theory.

The paper investigates the understanding of quantum indistinguishability after quantum information in comparison with the “classical” quantum mechanics based on the separable complex Hilbert space. The two oppositions, correspondingly “distinguishability / indistinguishability” and “classical / quantum”, available implicitly in the concept of quantum indistinguishability can be interpreted as two “missing” bits of classical information, which are to be added after teleportation of quantum information to be restored the initial state unambiguously. That new understanding of quantum indistinguishability is linked to (...) the distinction of classical (Maxwell-Boltzmann) versus quantum (either Fermi-Dirac or Bose-Einstein) statistics. The latter can be generalized to classes of wave functions (“empty” qubits) and represented exhaustively in Hilbert arithmetic therefore connectible to the foundations of mathematics, more precisely, to the interrelations of propositional logic and set theory sharing the structure of Boolean algebra and two anti-isometric copies of Peano arithmetic. (shrink)

After rejecting substance dualism, some naturalists embrace patternism. It states that persons are bodies and that bodies are material machines running abstract person programs. Following Aristotle, these person programs are souls. Patternists adopt four-dimensionalist theories of persistence: Bodies are 3D stages of 4D lives. Patternism permits at least six types of life after death. It permits quantum immortality, teleportation, salvation through advanced technology, promotion out of a simulated reality, computational monadology, and the revision theory of resurrection.

Some physicists seem to believe that quantum information theory requires a new concept of information (Jozsa, 1998, Quantum information and its properties. In: Hoi-Kwong Lo, S. Popescu, T. Spiller (Eds.), Introduction to Quantum Computation and Information, World Scientific, Singapore, (pp. 49-75); Deutsch & Hayden, 1999, Information flow in entangled quantum subsystems, preprint quant-ph/9906007). I will argue that no new concept is necessary. Shannon's concept of information is sufficient for quantum information theory. Properties that are cited to contrast quantum information and (...) classical information (i.e., Shannon information) actually point to differences in our ability to manipulate, access, and transfer information depending on whether quantum systems, opposed to classical systems, are used in a communication system. I also demonstrate that conceptually puzzling phenomena in quantum information theory, such as dense coding, teleportation, and Schumacher coding, all of which are cited as evidence that a new concept of information is required, do not have to be regarded as such. (shrink)

The surprising aspects of quantum information are due to two distinctly non-classical features of the quantum world: first, different quantum states need not be orthogonal and, second, quantum states may be entangled. Non-orthogonality leads to the blurring of classical distinctions. On the other hand, entanglement leads via non-locality to teleportation and other ``entanglement-assisted'' forms of communication that go beyond what is classically possible. In this article we attempt to understand these new possibilities via an analysis of the significance of (...) entanglement for the basic physical concepts of a ``particle'' and a ``localized physical system''. Classical particles can be individuated on the basis of qualitative differences in their sets of properties. But in entangled states the ``particle labels'' of the quantum formalism usually do not pick out such sets of individuating particle properties. It is sometimes nevertheless possible to think in terms of individual particles, which may be localized; but we argue that in general the structure of quantum mechanics is at odds with such a particle interpretation. This finally leads us to the conclusion that quantum mechanics is best seen as not belonging to the category of space-time theories, in which physical quantities are functions on space-time points. The resulting picture of the quantum world is relevant for our understanding of the way in which quantum theory is non-local, and it sheds light on the novel aspects of quantum information. (shrink)

Since the 20th century the quantum physics has shown various phenomena, judged as “seldom and not easily understandable” by the theories of classic physics. From the beginning of the “Kopenhagener Deutung,” Einstein claimed against Heisenberg, Bohr, etc. that the particle physics lacks “physical reality.” A number of physicists have tried to clarify the labyrinth of particle as a minimal substance in the phenomena of the micro world. The entanglement of the “double particle” emitted from a π-meson in its teleportation (...) is one of those phenomena. However, a successful new thesis has also become a target for the antithesis by deputies. Even if the “uncertainty” of an emitted light quantum that is received by the detector “either as a particle or as wave” has been reduced in our time by using probability calculations and new experimental physical facilities, the principal character of particles based on the “uncertainty relation” has not been changed. Although Heisenberg’s formula of the uncertainty relation could be “renewed” by completing certain operational components substituted by some physicists, the fundamental reality of phenomena of particle physics remain: The “physical reality” manifested by Einstein based on his glorious success of the Special and General Theory of Relativity cannot be valid in the micro-world phenomena.Pietschmann, a well-known theoretical physicist in Vienna, and Hashi, a philosopher teaching and researching interdisciplinary philosophy in Vienna, highlight the essential problems of particle physics and clarify them in regards to ontological and epistemological aspects. The dialogue has its origin in the hypothesis that the particle physics needs a logical interpretation with completely new ontological principles. In addition, the fundamental ontology of Mahayana Buddhist philosophy and its further development to rational philosophy of East Asia has various indications and contributions for an ontological epistemology of particle physics. (shrink)

Some physicists seem to believe that quantum information theory requires a new concept of information , Introduction to Quantum Computation and Information, World Scientific, Singapore, ; Deutsch & Hayden, 1999, Information flow in entangled quantum subsystems, preprint quant-ph/9906007). I will argue that no new concept is necessary. Shannon's concept of information is sufficient for quantum information theory. Properties that are cited to contrast quantum information and classical information actually point to differences in our ability to manipulate, access, and transfer information (...) depending on whether quantum systems, opposed to classical systems, are used in a communication system. I also demonstrate that conceptually puzzling phenomena in quantum information theory, such as dense coding, teleportation, and Schumacher coding, all of which are cited as evidence that a new concept of information is required, do not have to be regarded as such. (shrink)

The possibility of algorithmic consciousness depends on the assumption that conscious states can be copied or repeated by sufficiently duplicating their underlying physical states, leading to a variety of paradoxes, including the problems of duplication, teleportation, simulation, self-location, the Boltzmann brain, and Wigner’s Friend. In an effort to further elucidate the physical nature of consciousness, I challenge these assumptions by analyzing the implications of special relativity on evolutions of identical copies of a mental state, particularly the divergence of these (...) evolutions due to quantum fluctuations. By assuming the supervenience of a conscious state on some sufficient underlying physical state, I show that the existence of two or more instances, whether spacelike or timelike, of the same conscious state leads to a logical contradiction, ultimately refuting the assumption that a conscious state can be physically reset to an earlier state or duplicated by any physical means. Several explanatory hypotheses and implications are addressed, particularly the relationships between consciousness, locality, physical irreversibility, and quantum no-cloning. (shrink)

This article considers recent arguments against the proposition that one and the same object cannot go out of existence and then come into existence again (so that, e.g., teleportation would involve change of identity.). It argues that these arguments can be evaded by adopting a four-dimensional ontology, according to which human beings, trees, etc., have temporal as well as spatial parts.

We present a logical calculus for reasoning about information flow in quantum programs. In particular we introduce a dynamic logic that is capable of dealing with quantum measurements, unitary evolutions and entanglements in compound quantum systems. We give a syntax and a relational semantics in which we abstract away from phases and probabilities. We present a sound proof system for this logic, and we show how to characterize by logical means various forms of entanglement (e.g. the Bell states) and various (...) linear operators. As an example we sketch an analysis of the teleportation protocol. (shrink)

Building on Peres’ idea of “Delayed-choice for entanglement swapping” we show that even the degree to which quantum systems were entangled can be defined after they have been registered and may even not exist any more. This does not arise as a paradox if the quantum state is viewed as just a representative of information. Moreover such a view gives a natural quantification of the complementarity between the measure of information about the input state for teleportation and the amount (...) of entanglement of the resulting swapped entangled state. (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)

Gotthold Ephraim Lessing’s “dramatic poem” Nathan the Wise (1779) stood out at the time because it showed a Jew, Nathan, in a good light—a better light than the average Christian. Nathan is presented as a figure of wisdom largely on account of his approach to religious difference, especially among the religions represented by the three main protagonists: the Sultan Saladin (Islam), the Knight Templar (Christianity) and Nathan himself (Judaism). In the context of the conflicts of early modern Europe, his message—on (...) the nature of religious difference and the need for toleration—might well seem to earn him the epithet “wise.” This message, which is also the message of the play as a whole, is reinforced by the fact that it is a Jew who delivers it. But, on closer examination, is he the person that at first sight he appears to be? Furthermore, if he were teleported to the here and now, would his take on difference and toleration have enough heft? The essay interrogates the figure of Nathan and answers both questions in the negative. It argues that we need a new Nathan for our globalised, post-colonial, post-Shoah world: a Nathan who is wise in a different fashion. (shrink)

Drawing on compelling material from research interviews with former hostages and political prisoners, Guy Saunders reworks three classic thought experiment stories: Parfit's 'Teleporter', Nagel's 'What is it like to be a bat?' and Jackson's 'Mary the colour scientist' to form a fresh look at the study of consciousness. By examining consciousness from a social psychology perspective, Saunders develops a 'cubist psychology of consciousness' through which he challenges the accepted wisdom of mainstream approaches by arguing that people can act freely. What (...) makes 'cubist psychology' is both the many examples taken from different viewpoints and the multiple ways of looking at the key issues of person, mind and world. This is a unique and engaging book that will appeal to students and academics in the field of consciousness studies and other readers with an interest in consciousness. (shrink)

This article explores the geographical outlook of the late antique author Ausonius of Bordeaux (c.310–395 c.e.). It offers close readings of his poems on roads, oysters and cities, and situates him within the vibrant geographical debates of his day. Section I, on roads, argues that an overlooked passage in Epistula 24 reflects attested routes through Gaul, and that other passages in Ausonius’ letters are similarly influenced by ‘hodological’ ways of thinking. Section II, on oysters, identifies a new geographic mode, ‘teleports’, (...) in Epistula 3, a poem in a long tradition of works that use oysters to chart imperial space and map cultural landscapes. Section III, on cities, brings the recent paradigm of ‘landmarks’ to bear on the Ordo nobilium urbium, arguing that Ausonius uses the catalogue form both to articulate imperial unity and to express pride in his homeland of Gaul. This article thus advances our understanding of three related aspects of late antique geography: it demonstrates the importance of literary texts for discussions of cultural geography; shows how conceptions of space were influenced by provincial identity; and provides further evidence of the great diversity of Roman understandings of space. (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)

This chapter discusses problems for informational patternism and the popular soul theory of personal identity, suggests that they are incoherent, and urges that the self does not really exist. It employs the science fiction pseudotechnology of a teleporter and presents the example of split brains from actual neuroscience cases. There are two theories about what persons are, and what is involved in a person's continued existence over time. On the Ego Theory, a person's continued existence cannot be explained except as (...) the continued existence of a particular Ego, or subject of experiences. According to the Bundle Theory we must claim that there are long series of different mental states and events, each series being what we call one life. The split‐brain cases provide one argument for one view about the nature of persons. In the other, a person's brain is divided, and the halves are transplanted in two different bodies. (shrink)