In this paper I develop a framework for relating dualities and emergence: two notions that are close to each other but also exclude one another. I adopt the conception of duality as 'isomorphism', from the physics literature, cashing it out in terms of three conditions. These three conditions prompt two conceptually different ways in which a duality can be modified to make room for emergence; and I argue that this exhausts the possibilities for combining dualities and emergence. I apply this (...) framework to gauge/gravity dualities, considering in detail three examples: AdS/CFT, Verlinde's scheme, and black holes. My main point about gauge/gravity dualities is that the theories involved, qua theories of gravity, must be background-independent. I distinguish two senses of background-independence: minimalistic and extended. I argue that the former is sufficiently strong to allow for a consistent theory of quantum gravity; and that AdS/CFT is background-independent on this account; while Verlinde's scheme best fits the extended sense of background-independence. I argue that this extended sense should be applied with some caution: on pain of throwing the baby out with the bath-water. Nevertheless, it is an interesting and potentially fruitful heuristic principle for quantum gravity theory construction. It suggests some directions for possible generalisations of gauge/gravity dualities. The interpretation of dualities is discussed; and the so-called 'internal' vs. 'external' viewpoints are articulated in terms of: epistemic and metaphysical commitments; parts vs. wholes. I then analyse the emergence of gravity in gauge/gravity dualities in terms of the two available conceptualisations of emergence; and I show how emergence in AdS/CFT and in Verlinde's scenario differ from each other. Finally, I give a novel derivation of the Bekenstein-Hawking black hole entropy formula based on Verlinde's scheme; the derivation sheds light on several aspects of Verlinde's scheme and how it compares to Bekenstein's original calculation. (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)

The analysis of the measurement of gravitational fields leads to the Rosenfeld inequalities. They say that, as an implication of the equivalence of the inertial and passive gravitational masses of the test body, the metric cannot be attributed to an operator that is defined in the frame of a local canonical quantum field theory. This is true for any theory containing a metric, independently of the geometric framework under consideration and the way one introduces the metric in it. Thus, (...) to establish a local quantum field theory of gravity one has to transit to non-Riemann geometry that contains (beside or instead of the metric) other geometric quantities. From this view, we discuss a Riemann–Cartan and an affine model of gravity and show them to be promising candidates of a theory of canonical quantum gravity. (shrink)

The analysis of the measurement of gravitational fields leads to the Rosenfeld inequalities. They say that, as an implication of the equivalence of the inertial and passive gravitational masses of the test body, the metric cannot be attributed to an operator that is defined in the frame of a local canonical quantum field theory. This is true for any theory containing a metric, independently of the geometric framework under consideration and the way one introduces the metric in it. Thus, (...) to establish a local quantum field theory of gravity one has to transit to non-Riemann geometry that contains (beside or instead of the metric) other geometric quantities. From this view, we discuss a Riemann–Cartan and an affine model of gravity and show them to be promising candidates of a theory of canonical quantum gravity. (shrink)

Quantum gravity--the marriage of quantum physics with general relativity--is bound to contain deep and important lessons for the nature of physical time. Some of these lessons shall be canvassed here, particularly as they arise from quantum general relativity and string theory and related approaches. Of particular interest is the question of which of the intuitive aspects of time will turn out to be fundamental, and which 'emergent' in some sense.

We give an introductory review of gauge/gravity duality, and associated ideas of holography, emphasising the conceptual aspects. The opening sections gather the ingredients, viz. anti-de Sitter spacetime, conformal field theory and string theory, that we need for presenting, in Sect. 5, the central and original example: Maldacena’s AdS/CFT correspondence. Sections 6 and 7 develop the ideas of this example, also in applications to condensed matter systems, QCD, and hydrodynamics. Sections 8 and 9 discuss the possible extensions of holographic (...) ideas to de Sitter spacetime and to black holes. Section 10 discusses the bearing of gauge/gravity duality on two philosophical topics: the equivalence of physical theories, and the idea that spacetime, or some features of it, are emergent. (shrink)

The paper discusses the philosophical conclusions, which the interrelation between quantum mechanics and general relativity implies by quantum measure. Quantum measure is three-dimensional, both universal as the Borel measure and complete as the Lebesgue one. Its unit is a quantum bit (qubit) and can be considered as a generalization of the unit of classical information, a bit. It allows quantum mechanics to be interpreted in terms of quantum information, and all physical processes to be (...) seen as informational in a generalized sense. This implies a fundamental connection between the physical and material, on the one hand, and the mathematical and ideal, on the other hand. Quantum measure unifies them by a common and joint informational unit. Furthermore the approach clears up philosophically how quantum mechanics and general relativity can be understood correspondingly as the holistic and temporal aspect of one and the same, the state of a quantum system, e.g. that of the universe as a whole. The key link between them is the notion of the Bekenstein bound as well as that of quantum temperature. General relativity can be interpreted as a special particular case of quantum gravity. All principles underlain by Einstein (1918) reduce the latter to the former. Consequently their generalization and therefore violation addresses directly a theory of quantum gravity. Quantum measure reinterprets newly the “Bing Bang” theories about the beginning of the universe. It measures jointly any quantum leap and smooth motion complementary to each other and thus, the jump-like initiation of anything and the corresponding continuous process of its appearance. Quantum measure unifies the “Big Bang” and the whole visible expansion of the universe as two complementary “halves” of one and the same, the set of all states of the universe as a whole. It is a scientific viewpoint to the “creation from nothing”. (shrink)

Quantum gravity is understood as a theory that, in some sense, unifies general relativity (GR) and quantum theory, and is supposed to replace GR at extremely small distances (high-energies). It may be that quantum gravity represents the breakdown of spacetime geometry described by GR. The relationship between quantum gravity and spacetime has been deemed ``emergence'', and the aim of this thesis is to investigate and explicate this relation. After finding traditional philosophical accounts of (...) emergence to be inappropriate, I develop a new conception of emergence by considering physical case studies including condensed matter physics, hydrodynamics, critical phenomena and quantum field theory understood as effective field theory. This new conception of emergence is unconcerned with the ideas of reduction and derivation (i.e. it holds that we may have emergence with reduction or without it). Instead, a low-energy theory (or model) is understood as emergent from a high-energy theory if it is novel and autonomous compared to the high-energy theory, and the low-energy physics is dependent in a particular, minimal sense on the high-energy physics (this dependence is revealed by the techniques of effective field theory and the renormalisation group). While novelty is construed in a broad sense, the autonomy comes essentially from the underdetermination of the high-energy theory by the low-energy theory, which reflects the minimal way in which the emergent, low-energy theory depends on the high-energy one. It results from the scaling behaviour of the theories and the limiting relations between them, and is demonstrated by the renormalisation group and effective field theory techniques, the idea of universality, and the phenomenon of symmetry-breaking. These ideas are important in exploring the relationship between quantum gravity and GR, where GR is understood as an effective, low-energy theory of quantum gravity. Without experimental data or a theory of quantum gravity, we rely on principles and techniques from other areas of physics to guide the way. As well as considering the idea of emergence appropriate to treating GR as an effective field theory, I investigate the emergence of spacetime (and other aspects of GR) in several concrete approaches to quantum gravity, including examples of the condensed matter approaches, the ``discrete approaches'' (causal set theory, causal dynamical triangulations, quantum causal histories and quantum graphity) and loop quantum gravity. (shrink)

Recently there has been a great deal of interest in tabletop experiments intended to exhibit the quantum nature of gravity by demonstrating that it can induce entanglement. In order to evaluate these experiments, we must determine if there is any interesting class of possibilities that will be convincingly ruled out if it turns out that gravity can indeed induce entanglement. In particular, since one argument for the significance of these experiments rests on the claim that they demonstrate (...) the existence of superpositions of spacetimes, it is important to keep in mind that different interpretations of quantum mechanics may make different predictions about superpositions of spacetimes. ψ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\psi$$\end{document}-complete interpretations of quantum mechanics, like the Everett interpretation, almost universally predict the existence of superpositions of spacetimes, whereas in ψ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\psi$$\end{document}-incomplete, ψ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\psi$$\end{document}-nonphysical interpretations it seems more natural to predict that spacetime superpositions are not possible. Meanwhile ψ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\psi$$\end{document}-incomplete, ψ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\psi$$\end{document}-supplemented interpretations present us with a more complex picture where we may or may not end up predicting that spacetime superpositions are possible, depending on the particular way in which the coupling between spacetime and matter is constructed. This line of reasoning suggests that what would be ruled out by a successful result to these tabletop experiments is a class of quantum gravity models that we refer to as ψ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\psi$$\end{document}-incomplete quantum gravity —i.e. models of the interaction between quantum mechanics and gravity in which gravity is coupled to non-quantum beables rather than quantum beables. It follows that the results of tabletop experiments can also be regarded as giving us new evidence about the interpretation of quantum mechanics: roughly speaking, a positive result to these experiments should increase our confidence in ψ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\psi$$\end{document}-complete interpretations, whilst a negative result should instead increase our confidence in ψ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\psi$$\end{document}-incomplete interpretations. We introduce these ideas in Sect. 1, and then in Sect. 2 we make the reasoning more precise by presenting a set of inferences that may be made about the ontology of quantum mechanics based on the results of tabletop experiments. In Sect. 3 we discuss some existing PIQG models and consider what more needs to be done to make these sorts of approaches more appealing. There are two competing paradigms for the interpretation of these experiments, which have been dubbed the ‘Newtonian’ paradigm and the ‘tripartite’ paradigm: here we largely work within the tripartite paradigm, because the tripartite view is specifically concerned with ontological aspects of the mediating gravitational interaction and that makes it a suitable setting for enquiries about the ontology of quantum mechanics, but in Sect. 4 we consider what conclusions can be drawn if one does not presuppose the tripartite view. Finally in Sect. 5 we discuss a cosmological phenomenon which could be regarded as providing evidence for PIQG models. (shrink)

In this paper, I will argue that metaphysicians ought to utilize quantum theories of gravity as incubators for a future metaphysics. I will argue why this ought to be done and will present cases studies from the history of science where physical theories have challenged both the dogmatic and speculative metaphysician. I provide two theories of QG and demonstrate the challenge they pose to certain aspects of our current metaphysics; in particular, how they challenge our understanding of (...) the abstract–concrete distinction. I demonstrate how five different accounts of the distinction each fail to hold under the received interpretations of loop quantum gravity and string theory. The central goal of this paper is to encourage metaphysicians to look to physical theories, especially those involving cosmology such as string theory and loop quantum gravity, when doing metaphysics. (shrink)

In Crull it is argued that, in order to confront outstanding problems in cosmology and quantum gravity, interpretational aspects of quantum theory can by bypassed because decoherence is able to resolve them. As a result, Crull concludes that our focus on conceptual and interpretational issues, while dealing with such matters in Okon and Sudarsky, is avoidable and even pernicious. Here we will defend our position by showing in detail why decoherence does not help in the resolution (...) of foundational questions in quantum mechanics, such as the measurement problem or the emergence of classicality. (shrink)

The physical, mathematical, and philosophical foundations of the quantum theory of free Bose fields in fixed general relativistic spacetimes are examined. It is argued that the theory is logically and mathematically consistent whereas semiclassical prescriptions for incorporating the back-reaction of the quantum field on the geometry lead to inconsistencies. Still, the relations and heuristic value of the semiclassical approach to canonical and covariant schemes of quantum gravity-plus-matter are assessed. Both conventional and rigorous formulations of the theory (...) and of its principal predictions, cosmological particle creation and horizon radiation, are expounded and compared. Special attention is devoted to spacetime properties needed for the existence or uniqueness of the relevant theoretical elements , renormalization of the stress tensor). The emergence of unitarily inequivalent representations in a single dynamical context is used as motivation for the introduction of the abstract $\rm C\sp{\*}$-algebraic axiomatic formalism. The operationalist and conventionalist claims of the original abstract algebraic program are criticized in favor of its tempered outgrowth, local quantum physics. The interpretation of the theory as a wave mechanics of classical field configurations, deriving from the Schrodinger representations of the abstract algebra, is discussed and is found superior, at least on the level of analogy, to particle or harmonic oscillator interpretations. Further, it is argued that the various detector results and the Fulling nonuniqueness problem do not undermine the particle concept in the ways commonly claimed. In particular, arguments are offered against the attribution of particle status to the Rindler quanta, against the physical realizability of the Rindler vacuum, and against the more general notion of observer-dependence as to the definition of 'particle' or 'vacuum'. However, the question of the ontological status of particles is raised in terms of the consistency of quantum field theory with non-reductive realism about particles, the latter being conceived as entities exhibiting attributes of discreteness and localizability. Two arguments against non-reductive realism about particles, one from axiomatic algebraic local quantum theory in Minkowski spacetime and one from quantum field theory in curved spacetime, are developed. (shrink)

It is shown that the one-loop effective action of unimodular gravity is the same as that of ordinary gravity, restricted to unimodular metrics. The only difference is in the treatment of the global scale degree of freedom and of the cosmological term. A constant vacuum energy does not gravitate, addressing one aspect of the cosmological constant problem.

We survey some philosophical aspects of the search for a quantum theory of gravity, emphasising how quantum gravity throws into doubt the treatment of spacetime common to the two `ingredient theories' (quantum theory and general relativity), as a 4-dimensional manifold equipped with a Lorentzian metric. After an introduction (Section 1), we briefly review the conceptual problems of the ingredient theories (Section 2) and introduce the enterprise of quantum gravity (Section 3). We then (...) describe how three main research programmes in quantum gravity treat four topics of particular importance: the scope of standard quantum theory; the nature of spacetime; spacetime diffeomorphisms, and the so-called `problem of time' (Section 4). These programmes are the old particle-physics approach, superstring theory, and canonical quantum gravity. By and large, these programmes accept most of the ingredient theories' treatment of spacetime, albeit with a metric with some type of quantum nature; but they also suggest that the treatment has fundamental limitations. This prompts the idea of going further: either by quantizing structures other than the metric, such as the topology; or by regarding such structures as phenomenological. We discuss this in Section 5. (shrink)

In times of crisis, when current theories are revealed as inadequate to task, and new physics is thought to be required—physics turns to re-evaluate its principles, and to seek new ones. This paper explores the various types, and roles of principles that feature in the problem of quantum gravity as a current crisis in physics. I illustrate the diversity of the principles being appealed to, and show that principles serve in a variety of roles in all stages of (...) the crisis, including in motivating the need for a new theory, and defining what this theory should be like. In particular, I consider: the generalised correspondence principle, UV-completion, background independence, and the holographic principle. I also explore how the current crisis fits with Friedman’s view on the roles of principles in revolutionary theory-change, finding that while many key aspects of this view are not represented in quantum gravity, the view could potentially offer a useful diagnostic, and prescriptive strategy. This paper is intended to be relatively non-technical, and to bring some of the philosophical issues from the search for quantum gravity to a more general philosophical audience interested in the roles of principles in scientific theory-change. (shrink)

In this paper, we argue that what is often discussed under the umbrella of `spacetime emergence' in the philosophy of quantum gravity in fact consists of a plethora of distinct and even highly different problems. We therefore advocate to cast such debates more specifically in terms of the emergent spatiotemporal aspects, as is already done in the physics literature. We first show how ambiguous the notion of spacetime is already in general relativity. We then argue against three (...) ways to reject our call for specificity: the many distinct philosophical problems relating to the emergence of the various spatiotemporal aspects do not suggest any singular, overarching, or exceptional problem of spacetime emergence. We also discuss how the objections are reflected by five conceptions of spacetime. Next, we observe that different spatiotemporal aspects are emergent in the different quantum gravity approaches, whereby investigating emergence in quantum gravity collectively is problematic. Finally, we illustrate how philosophical inquiries that employ notions of spacetime emergence are aided by conducting the investigation at the level of specific spatiotemporal aspects. (shrink)

I argue that quantum decoherence—understood as a dynamical process entailed by the standard formalism alone—carries us beyond conceptual aspects of non-relativistic quantum mechanics deemed insurmountable by many contributors to the recent quantum gravity and cosmology literature. These aspects include various incarnations of the measurement problem and of the quantum -to-classical puzzle. Not only can such problems be largely bypassed or dissolved without default to a particular interpretation, but theoretical work in relativistic arenas stands (...) to gain substantial physical and philosophical insight by incorporating decoherence phenomena. (shrink)

The physical concept of locality is first analyzed in the special relativistic quantum regime, and compared with that of microcausality and the local commutativity of quantum fields. Its extrapolation to quantum general relativity on quantum bundles over curved spacetime is then described. It is shown that the resulting formulation of quantum-geometric locality based on the concept of local quantum frame incorporating a fundamental length embodies the key geometric and topological aspects of this concept. (...) Taken in conjunction with the strong equivalence principle and the path-integral formulation of quantum propagation, quantum-geometric locality leads in a natural manner to the formulation of quantum-geometric propagation in curved spacetime. Its extrapolation to geometric quantum gravity formulated over quantum spacetime is described and analyzed. (shrink)

A recent debate has ensued over the claim in Pikovski et al. that systems with internal degrees of freedom undergo a universal, gravity-induced, type of decoherence that explains their quantum-to-classical transition. Such decoherence is supposed to arise from the different gravitational redshifts experienced by such systems when placed in a superposition of two wave packets at different heights in a gravitational field. Here we investigate some aspects of the discussion with the aid of simple examples. In particular, (...) we first resolve an apparent conflict between the reported results and the equivalence principle by noting that the static and free fall descriptions focus on states associated with different hypersurfaces. Next, we emphasize that predictions regarding the observability of interference become relevant only in the context of concrete experimental settings. As a result, we caution against hasty claims of universal validity. Finally, we dispute the claim that, at least in the scenarios discussed in Pikovski et al., gravitation is responsible for the reported results and we question the alleged ability of decoherence to explain the quantum-to-classical transition. In consequence, we argue against the extraordinary assertion in Pikovski et al. that gravity can account for the emergence of classicality. (shrink)

In this paper I analyse two closely related examples of duality and of emergence of gravity, namely AdS/CFT and Verlinde's scheme. Based on the notion of duality introduced in Dieks et al., I here elaborate on the conditions necessary for AdS/CFT to be a duality, in particular the condition of completeness. I also address what is usually seen as a desideratum for any candidate theory of quantum gravity: the background-independence of the theory and the diffeomorphism invariance of (...) the observables. Then I discuss Verlinde's scheme and the extent to which it gives a clear case of emergence of gravity. Finally, I give a novel derivation of the Bekenstein-Hawking black hole entropy formula based on Verlinde's scheme. (shrink)

continent. 1.3 (2011): 149-155. The world is teeming. Anything can happen. John Cage, “Silence” 1 Autonomy means that although something is part of something else, or related to it in some way, it has its own “law” or “tendency” (Greek, nomos ). In their book on life sciences, Medawar and Medawar state, “Organs and tissues…are composed of cells which…have a high measure of autonomy.”2 Autonomy also has ethical and political valences. De Grazia writes, “In Kant's enormously influential moral philosophy, autonomy (...) , or freedom from the causal determinism of nature, became prominent in justifying the human use of animals.”3 One of the oldest uses of autonomy in English is a description of the French civil war from the late sixteenth century: “Others of the…rebellion entred in counsell, whether they ought to admit the King vpon reasonable conditions, specially hauing their autonomy.”4 Life, and in particular human life, and in particular human politics, is well served by the usages of autonomy . What about the rest of reality, however? Should it be thought of, if it's even considered real and mind-independent, as pure stuff for the manipulation or decorative tastes of truly autonomous beings? We tend to think of things such as paperweights and iPhones as mere tools of human design and human use. To use them is to cause them to exist as fully and properly as they can. But according to Martin Heidegger, when a tool such as a paperweight is used, it disappears, or withdraws ( Entzug ). We are preoccupied with copying the page that the paperweight is holding down. We are concerned with an essay deadline, and the paperweight simply disappears into this general project. If the paperweight slips, or if the iPhone freezes, we might notice it. All of a sudden it becomes vorhanden (present-at-hand) rather than zuhanden (ready-to-hand).5 Yet Heidegger is unable to draw a meaningful distinction between what happens to a paperweight when it slips from the book I'm copying from and what happens to the paperweight when it presses on the still resilient pages of the thick paperback itself. Further still and related to this point, even when I am using the paperweight as part of some general task, I am not using the entirety of the paperweight as such. My project itself selects a thin slice of paperweight-being for the purposes of holding down a book. Even when it is zuhanden the paperweight is withdrawn. Graham Harman is the architect of this way of thinking.6 Harman discovered a gigantic coral reef of withdrawn entities beneath the Heideggerian submarine of Da-sein, which itself is operating at an ontological depth way below the choppy surface of philosophy, beset by the winds of epistemology, and infested with the sharks of materialism, idealism, empiricism and most of the other isms that have defined what is and what isn't for the last several hundred years. At a moment when the term ontology was left alone like a piece of well chewed old chewing gum that no one wants to have anything to do with, object-oriented ontology (OOO) has put it back on the table. The coral reef isn't going anywhere and once you have discovered it, you can't un-discover it. And it seems to be teeming with strange facts. The first fact is that the entities in the reef—we call them “objects” somewhat provocatively—constitute all there is: from doughnuts to dogfish to the Dog Star to Dobermans to Snoop Dogg. People, plastic clothes pegs, piranhas and particles are all objects. And they are all pretty much the same, at this depth. There is not much of a distinction between life and non-life (as there isn't in contemporary life science). And there is not much of a distinction between intelligence and non-intelligence (as there is in contemporary artificial intelligence theory). A lot of these distinctions are made by humans, for humans (anthropocentrism). And the concept autonomy has come into play in policing such distinctions. In this essay I shall to try to liberate autonomy for the sake of nonhumans. I shall do so by parsing carefully the title, which is taken from Hakim Bey's work The Temporary Autonomous Zone .8 First we shall explore the term autonomous . Then we shall explore what the full meaning of zone is. Finally, we shall investigate what temporary means. Each of these terms is of great value. An object withdraws from access. This means that its very own parts can't access it. Since an object's parts can't fully express the object, the object is not reducible to its parts. OOO is anti-reductionist. But OOO is also anti-holist. An object can't be reduced to its “whole” either, “reduced upwards” as it were. The whole is not greater than the sum of its parts. So we have a strange irreductionist situation in which an object is reducible neither to its parts nor to its whole. A coral reef is made of coral, fish, seaweed, plankton and so on. But one of these things on its own doesn't embody part of a reef. Yet the reef just is an assemblage of these particular parts. You can't find a coral reef in a parking lot. In this way, the vibrant realness of a reef is kept safe both from its parts and from its whole. Moreover, the reef is safe from being mistaken for a parking lot. Objects can't be reduced to tiny Lego bricks such as atoms that can be reused in other things. Nor can be reduced upwards into instantiations of a global process. A coral reef is an expression of the biosphere or of evolution, yes; but so is this sentence, and we ought to be able to distinguish between coral reefs and sentences in English. The preceding facts go under the heading of undermining . Any attempt to undermine an object—in thought, or with a gun, or with heat, or with the ravages of time or global warming—will not get at the withdrawn essence of the object. By essence is meant something very different from essentialism . This is because essentialism depends upon some aspect of an object that OOO holds to be a mere appearance of that object, an appearance-for some object. This reduction to appearance holds even if that object for which the appearance occurs is the object itself! Even a coral reef can't grasp its essential coral reefness. In essentialism, a superficial appearance is taken for the essence of a thing, or of things in general. In thinking essentialism we may be able to discern another way of avoiding OOO. This is what Harman has christened overmining .? The overminer decides that some things are more real than others: say for example human perception. Then the overminer decides that other things are only granted realness status by somehow coming into the purview of the more real entity. When I measure a photon, when I see a coral reef, it becomes what it is. But when I measure a photon, I never measure the actual photon. Indeed, since at the quantum scale to measure means “to hit with a photon or an electron beam” (or whatever), measurement, perception ( aisthesis ), and doing become the same. What I “see” are deflections, tracks in a diffusion cloud chamber or interference patterns. Far from underwriting a world of pure illusion where the mind is king, quantum theory is one of the very first truly rigorous realisms, thinking its objects as irreducibly resistant to full comprehension, by anything.9 So far we have made objects safe from being swallowed up by larger objects and broken down into smaller objects—undermining. And so far we have made objects safe from being mere projections or reflections of some supervenient entity—overmining. That's quite a degree of autonomy. Everything in the coral reef, from the fish to a single coral lifeform to a tiny plankton, is autonomous. But so is the coral reef itself. So are the heads of the coral, a community of tiny polyps. So is each individual head. Each object is like one of Leibniz's monads, in that each one contains a potentially infinite regress of other objects; and around each object, there is a potentially infinite progress of objects, as numerous multiverse theories are now also arguing. But the infinity, the uncountability, is more radical than Leibniz, since there is nothing stopping a group of objects from being an object, just as a coral reef is something like a society of corals. Each object is “a little world made cunningly” (John Donne).10 We are indeed approaching something like the political valance of autonomy . The existence of an object is irreducibly a matter of coexistence. Objects contain other objects, and are contained “in” other objects. Let us, however, explore further the ramifications of the autonomy of objects. We will see that this mereological approach (based on the study of parts) only gets at part of the astonishing autonomy of things. Yet there are some more things to be said about mereology before we move on. Consider the fact that since objects can't be undermined or overmined, it means that there is strictly no bottom object . There is no object to which all other objects can be reduced, so that we can say everything we want to say about them, hypothetically at least, based on the behavior of the bottom object. The idea that we could is roughly E.O Wilson's theory of consilience .11 Likewise, there is no object from which all things can be produced, no top object . Objects are not emanations from some primordial One or from a prime mover. There might be a god, or gods. Suppose there were. In an OOO universe even a god would not know the essential ins and outs of a piece of coral. Unlike even some forms of atheism, the existence of god (or nonexistence) doesn't matter very much for OOO. If you really want to be an atheist, you might consider giving OOO a spin. If there is no top object and no bottom object, neither is there a middle object . That is, there is no such thing as a space, or time, “in” which objects float. There is no environment distinct from objects. There is no Nature (I capitalize the word to reinforce a sense of its deceptive artificiality). There is no world, if by world we mean a kind of “rope” that connects things together.12 All such connections must be emergent properties of objects themselves. And this of course is well in line with post-Einsteinian physics, in which spacetime just is the product of objects, and which may even be an emergent property of a certain scale of object larger than 10?¹?cm).13 Objects don't sit in a box of space or time. It's the other way around: space and time emanate from objects. How does this happen? OOO tries to produce an explanation from objects themselves. Indeed, the ideal situation would be to rely on just one single object. Otherwise we are stuck with a reality in which objects require other entities to function, which would result in some kind of undermining or overmining. We shall see that we have all the fuel we need “inside” one object to have time and space, and even causality. We shall discover that rather than being some kind of machinery or operating system that underlies objects, causality itself is a phenomenon that floats ontologically “in front of” them. In so doing, we will move from the notion of autonomy and begin approaching a full exploration of the notion of zone , which was promised at the outset of this essay. Since an object is withdrawn, even “from itself,” it is a self-contradictory being. It is itself and not-itself, or in a slightly more expanded version, there is a rift between essence and appearance within an object (as well as “between” them). This rift can't be the same as the clichéd split between substance and accidents , which is the default ontology. On this view, things are like somewhat boring cupcakes with somewhat less boring sugar sprinkles on them of different colors and shapes. But on the OOO view, what is called substance is just another limited slice of an object, a way of apprehending something that is ontologically fathoms deeper. What is called substance and what is called accidence are just on the side of what this essay calls appearance. The rift (Greek, chorismos ) between essence and appearance means that an object presents us with something like what in logic is known as the Liar: some version of the sentence “This sentence is false.” The sentence is true, which means that it is a lie, which means that it is false. Or the sentence is false, which means that it is telling the truth, which means that it is true. Now logic since Aristotle has tried desperately to quarantine such beasts in small backwaters and side streets so that they don't act too provocatively.14 But if OOO holds, then at least one very significant thing in the universe is both itself and not-itself: the object. An object is p ? ¬p. To cope with this fact, we shall need some kind of paraconsistent or even fully dialetheic logic, one that is not allergic to dialetheias (double-truthed things). Yet if we accept that objects are dialetheic, p ? ¬p, we can derive all kinds of things easily from objects. Consider the fact of motion. If objects only occupy one location “in” space at any “one” time, then Zeno's paradoxes will apply to trying to think how an object moves. Yet motion seems like a basic, simple fact of our world. Either everything is just an illusion and nothing really moves at all (Parmenides). Or objects are here and not-here “at the same time.”15 This latter possibility provides the basic setup for all the motion we could wish for. Objects are not “in” time and space. Rather, they “time” (a verb) and “space.” They produce time and space. It would be better to think these verbs as intransitive rather than transitive, in the manner of dance or revolt . They emanate from objects, yet they are not the object. “How can we know the dancer from the dance?” (Yeats).16 The point being, that for there to be a question, there must be a distinction—or there must not be (p ? ¬p).17 It becomes impossible to tell: “What constitutes pretense is that, in the end, you don't know whether it's pretense or not.”18 In this notion of the emergence of time and space from an object we can begin to understand the term zone . Zone can mean belt , something that winds around something else. We talk of temperate zones and war zones. A zone is a place where a certain action is taking place: the zone winds around, it radiates heat, bullets fly, armies are defeated. To speak of an autonomous zone is to speak of a place that a certain political act has carved out of some other entity. Cynically, Tibet is called TAR, the Tibetan Autonomous Region, for this very reason. In this phrase, Region tries to emulate zone : it sounds as if the place has its own rules, but of course, it is very much under the control of China. What action is taking place? “[N]ot something that just is what it is, here and now, without mystery, but something like a quest…a tone on its way calling forth echoes and responses…water seeking its liquidity in the sunlight rippling across the cypresses in the back of the garden.”19 If as suggested earlier there is no functional difference between substance and accidence; if there is no difference between perceiving and doing; if there is no real difference between sentience and non-sentience—then causality itself is a strange, ultimately nonlocal aesthetic phenomenon. A phenomenon, moreover, that emanates from objects themselves, wavering in front of them like the astonishingly beautiful real illusion conjured in this quotation of Alphonso Lingis. Lingis's sentence does what it says, casting a compelling, mysterious spell, the spell of causality, like a demonic force field. A real illusion: if we knew it was an illusion, if it were just an illusion, it would cease to waver. It would not be an illusion at all. We would be in the real of noncontradiction. Since it is like an illusion, we can never be sure: “What constitutes pretense…” A zone is what Lingis calls a level . A zone is not entirely a matter of “free will”: this concept has already beaten down most objects into abject submission. Objects are far more threateningly autonomous, and sensually autonomous, than the Kantian version of autonomy cited in the first paragraph of this essay. A zone is not studiously decided upon by an earnest committee before it goes into action. One of its predominant features is that it is already happening . We find ourselves in it, all of a sudden, in the late afternoon as the shadows lengthen around a city square, giving rise to an uncanny sensation of having been here before. Objects emit zones. Wherever I find myself a zone is already happening, an autonomous zone. It is the nonautonomous zones that are impositions on what is already the case. Or rather, these zones are autonomous zones that exclude and police. They are brittle. Every object is autonomous, but some objects try to maintain themselves through rigidity and brittleness, like (and such as) a police state. Paradoxically, the more rigidly one tries to exclude contradiction, the more virulent become the dialetheias that are possible. I can get around “This sentence is false” by imagining that there are metalanguages that explain what counts as a sentence. Then I can decide that this isn't a real sentence. This is basically Alfred Tarski's strategy, since he invented the notion of metalanguage specifically to cope with dialetheias.20 For example we might claim that sentences such as “This sentence is false” are neither true nor false. But then you can imagine a strengthened version of the Liar such as: “This sentence is not true”; or “This sentence is neither true nor false.” And we can go on adding to the strengthened Liar if the counter-attack tries to build immunity by specifying some fourth thing that a sentence can be besides true, false, and neither true nor false: “This sentence is false, or neither true nor false, or the fourth thing.” And so on.21 It seems as if language becomes more brittle the more it tries to police the Liars of this world. Why? I believe that this increasing brittleness is a symptom of a deep fact about reality. What is this deep fact? Simply that there are objects, that these objects are withdrawn, and that they are walking contradictions. This means indeed that (as Lacan put it) “there is no metalanguage,” since a metalanguage would function as a “middle object” that gave coherency and evenness to the others.22 Since there is no metalanguage, there is no rising above the disturbing illusory play of causality. This may even have political implications: no global critique is therefore possible, and attempts to smooth out or totalize are doomed to fail. To think the zone is to think the notion of temporary , which we shall now begin to discuss in greater detail. The zone is not in time: rather it “times.” But because a zone is an emanation of an object, it is based on a wavering fragility, since objects are p ? ¬p. When an object is born, that means that it has broken free of some other object. An object can be born because it and other objects are fragile. If not, no movement would be possible. Objects contain the seeds of their own destruction, a dialetheic sentence that says something like “This sentence cannot be proved.” Kurt Gödel argues that every true system of propositions contains at least one sentence that the system cannot prove. In order to be true, the system must have a minimum incoherence. To be real, it has to be fragile. Imagine a record player. Now imagine a record called I Cannot Be Played on This Record Player . When you play it on this record player, it produces sympathetic vibrations that cause the record player to shudder apart. No matter how many defense mechanisms you build in, there will always be the possibility of at least one record that destroys the record player.23 That is what being physical is. An object is inherently fragile because it is both itself and not-itself. When the rift between appearance and essence collapses, that is called destruction, ending, death. When an object breaks, several new objects are born. An opera singer sings a loud note in tune with the resonant frequency of a wine glass. (See the movie included below.) The singing is a zone, an autonomous level of intensity, opening a rift between appearance and essence. The glass ripples—for a moment it is nakedly a glass and a not-glass—almost as if it were having an orgasm, a little death. It is caught in the rift of the singing. Then its structure can't handle the coherence of the sound waves, and it breaks. It is incoherence and inconsistency that is the mark of existence, not consistency and noncontradiction. When things break or die, they become coherent. Essence disappears into appearance. I become the memories of friends. A glass becomes a dancing wave. Instantly, there are glass fragments, new temporary autonomous zones. The fragments have broken free from the glass. They are no longer its parts, but emanate their own time and space, becoming perhaps accidental weapons as they bury themselves in my flesh. Thus Hakim Bey's instructions on creating temporary autonomous zones oscillate disturbingly between performance art and politics, circus clowning and revolution. To play with the aesthetic is to play with causality, to rip from the sensual ether emanating from things new regions, new zones. Anarchist politics is the creation of fresh objects in a reality without a top or a bottom object, or for that matter a middle object: Everything in nature is perfectly real including consciousness, there's absolutely nothing to worry about. Not only have the chains of the Law been broken, they never existed; demons never guarded the stars, the Empire never got started, Eros never grew a beard. … There is no becoming, no revolution, no struggle, no path; already you're the monarch of your own skin—your inviolable freedom waits to be completed only by the love of other monarchs: a politics of dream, urgent as the blueness of sky.24 Bey imagines that this is because chaos is a primordial “undifferentiated oneness-of-being.” A Parmenides or a Spinoza or a Laruelle would read this a certain way. Individual objects, or decisions to talk about this rather than that, are just maggot-like things crawling around on the surface of the giant cheese of oneness.25 Yet he also describes chaos as “Primordial uncarved block, sole worshipful monster, inert & spontaneous, more ultraviolet than any mythology.” This image is of an inconsistent object, not of an undifferentiated field. An object, indeed, that can be distinguished from other things. If not, then the first part of The Temporary Autonomous Zone , subtitled “The Broadsheets of Ontological Anarchism,” is a kind of onto-theology. Onto-theology proclaims that some things are more real than others. Bey, however, is writing poetically, and thus ambiguously. We are at liberty to read “undifferentiated oneness-of-being” as something like the irreducibility of a thing to its parts and so forth (undermining and overmining). This certainly seems closer to the language in the following paragraph: “There is no becoming … already you're the monarch of your own skin.”26 On this view, there is no difference between art and politics: “When ugliness, poor design & stupid waste are forced upon you, turn Luddite, throw your shoe in the works, retaliate.” Since Romanticism this has been the war cry of the vanguard artist.27 To say to is to fall prey to the tired axioms of the avant-garde, and we think we know how the game goes. But OOO is not simply a way to advocate “new and improved” versions of this shock-the-bourgeoisie boredom. Bey's text is certainly full enough of that. Rather, since causality as such is aesthetic, and since nonhumans are not that different from humans, the new approach would be to form aesthetic–causal alliances with nonhumans. These alliances would have to resist becoming brittle, whether that brittleness is right wing (authoritarianism) or left wing (the endless maze of critique). No “ism,” especially not the ultimate forms, nihilism and cynicism, is in any sense effective at this point. All forms of brittleness are based on the mistaken assumption that there is a metalanguage and that therefore “Anything you can do, I can do meta.” I will not be listing any approaches here, as Bey does. Such lists and manifestos belong to the vanguardism that no longer works. Why? Not because of some marvelous revolution in human consciousness, but because nonhumans have so successfully impinged upon human social, psychic and aesthetic space. It is the time after the end of the world. That happened in 1945, when a thin layer of radioactive materials was deposited in Earth's crust. Geology now calls it this era the Anthropocene . Ironically, this period, named after humans, is the moment at which even the most thick headed of us make decisive contact with nonhumans, from mercury in our blood to manta rays to magnesium. Richard Dawkins, Pat Robertson and Lady Gaga all have to deal with global warming and mass extinction, somehow. We now live in an Age of Asymmetry marked by a skewed, spiraling relationship between vast knowledge and vast nonhuman things—both become vaster and vaster because of one another and for the same reasons.28 This means that coming up with the perfect attitude or the perfect aesthetic prescription just won't work any more. Even the most hardened anthropocentrist now has to pay through the nose for basic food supplies, and has to use more sunscreen. Whether he knows it or acknowledges it, he is already acting with regard towards nonhumans. There is nothing special to think, no special critique that will get rid of the stains of coexistence. The problem won't fit into the well-established modern boxes, which is why the “mystical,” “spiritual” quality of Bey's prose is welcome. Of course, when I put it this way, you may immediately close off and decide that I am talking about perfect attitudes after all, or something outside of politics, or other ways that the radical left marshals to police its thinking of the nonhuman. Because that is what is really at stake in all this: the nonhuman in its coexistence with the human—bosons, gods, clouds, spirits, lifeforms, experiences, the sunlight rippling across the cypresses. Bey begins to get at this in a Latour litany in the second part of The Temporary Autonomous Zone , “The Assassins”: Pomegranate, mulberry, persimmon, the erotic melancholy of cypresses, membrane-pink shirazi roses, braziers of meccan aloes & benzoin, stiff shafts of ottoman tulips, carpets spread like make-believe gardens on actual lawns—a pavilion set with a mosaic of calligrammes—a willow, a stream with watercress—a fountain crystalled underneath with geometry— the metaphysical scandal of bathing odalisques, of wet brown cupbearers hide-&-seeking in the foliage—“water, greenery, beautiful faces.”29 This will be conveniently dismissed as orientalism. If we're never allowed to escape the crumbling prison of modernity for fear of imperialism there is truly no hope. In a similar way, the fear of anthropocentrism and anthropomorphism is very often staged from a place that just is anthropocentrism .30 Critique turns into ressentiment . An object radiates a zone that is aesthetic and therefore causal. Because objects “time” they are temporary. Not because they exist “in” time that eventually gets the better of them. Their very existence implies the possibility of their non-existence. Since objects are not consistent, they can cease to exist. But nothing, no one, will ever be able to insert a blade between appearance and existence, even thought there is a rift there. Now that's what I call autonomy. NOTES 1. John Cage, Silence: Lectures and Writings (Middletown, CT: Wesleyan University Press, 1973), 96. 2. P. B. Medawar and J. S. Medawar, The Life Science: Current Ideas in Biology (London: Wildwood House, 1977), 8. 3. David DeGrazia, Animal Rights: A Very Short Introduction (Oxford: Oxford University Press, 2002), 5. 4. Antony Colynet, A True History of the Civil Warres in France (London, 1591), 480. 5. Martin Heidegger, Being and Time , tr. Joan Stambaugh (Albany, N.Y: State University of New York Press, 1996) 62–71. 6. Graham Harman, Tool-Being: Heidegger and the Metaphysics of Objects (Peru, IL: Open Court, 2002). 7. Hakim Bey, The Temporary Autonomous Zone (Brooklyn: Autonomedia, 1991). 8. Graham Harman, The Quadruple Object (Ripley: Zero Books, 2011), 7–18. 9. This is not the place to get into an argument about quantum theory, but I have argued that quanta also do not endorse a world that I can't speak about because it is only real when measured. This world is that of the reigning Standard Model proposed by Niels Bohr and challenged by De Broglie and Bohm (and now the cosmologist Valentini, among others). See Timothy Morton, “Here Comes Everything: The Promise of Object-Oriented Ontology,” Qui Parle 19.2 (Spring–Summer, 2011), 163–190. 10. John Donne, Holy Sonnets 15, in The Major Works: Including Songs and Sonnets and Sermons , ed. John Carey (Oxford: Oxford University Press, 2009). 11. Edward O. Wilson, Consilience: The Unity of Knowledge (New York: Knopf, 1998). 12. Martin Heidegger, What Is a Thing? (Washington: Regnery, 1968), 243. 13. Albert Einstein, Relativity: The Special and the General Theory (London: Penguin, 2006); Petr Horava, “Quantum Gravity at a Lifshitz Point,” arXiv:0901.3775v2 [hep-th]. 14. Graham Priest, In Contradiction (Oxford University Press, 2006), passim: the most notable recent quarantine officers have been Tarski, Russell, and Frege. 15. Priest, In Contradiction , 172–181. 16. William Butler Yeats, “Among School Children,” Collected Poems , ed. Richard J. Finneran (New York: Scribner, 1996). 17. Paul de Man, “Semiology and Rhetoric,” Diacritics 3.3 (Autumn, 1973), 27–33 (30). 18. Jacques Lacan, Le seminaire, Livre III: Les psychoses (Paris: Editions de Seuil, 1981), 48. See Slavoj Zizek, The Parallax View (Cambridge, Mass.: MIT Press, 2006), 206. 19. Alphonso Lingis, The Imperative (Bloomington: Indiana University Press, 1998), 29. 20. Priest, In Contradiction , 9–27. 21. See Graham Priest and Francesco Berto, “ Dialetheism ,” The Stanford Encyclopedia of Philosophy (Summer 2010 Edition), ed. Edward N. Zalta. 22. Jacques Lacan, Écrits: A Selection , tr. Alan Sheridan (London: Tavistock, 1977), 311. 23. The analogy can be found at length in Douglas Hofstadter, “Contracrostipunctus,” Gödel, Escher, Bach: An Eternal Golden Braid (New York: Basic Books, 1999), 75–81. 24. Bey, “ Chaos: The Broadsheets of Ontological Anarchism ,” Temporary Autonomous Zone . 25. This is closest to the language of François Laruelle in Philosophies of Difference: A Critical Introduction to Non-Philosophy (New York: Continuum, 2011) 179. 26. Bey, “ Chaos: The Broadsheets of Ontological Anarchism ,” Temporary Autonomous Zone . 27. Peter Bürger, Theory of the Avant Garde (Minneapolis: University of Minnesota Press, 1984). 28. For further discussion see Timothy Morton, “From Modernity to the Anthropocene: Ecology and Art in the Age of Asymmetry,” The International Social Science Journal 209 (forthcoming). 29. Bey, “ The Assassins ,” Temporary Autonomous Zone . 30. Timothy Morton, The Ecological Thought (Cambridge, Mass.: Harvard University Press, 2010), 75–76. (shrink)

Wolfgang Pauli referred to him as 'my discovery,' Robert Oppenheimer described him as 'one of the most gifted theorists' and Niels Bohr found him enormously stimulating. Who was the man in question, Gunnar Källén (1926-1968)? His appearance in the physics sky was like a shooting star. His contributions to the scientific debate caused excitement among young and old. Similar to his friend and mentor, Wolfgang Pauli, he demanded honesty and rigor in physics - a distinct dividing line between fact and (...) speculation. In his obituary, Arthur S. Wightman would write: 'Gunnar Källén was a proud continuer of the tradition in quantum field theory established by Wolfgang Pauli. His papers on quantum electrodynamics in the period 1950-1954 carried the non-perturbative approach to quantum electrodynamics forward to a point beyond which very little essential progress has been made up to the present day. At the time I was trying to puzzle out the grammar of the language of quantum field theory, and here was Källén already writing poetry in the language!'. In addition to being a remarkable scientist, Källén had a very interesting personality, well worth exploring. In her book, physicist Cecilia Jarlskog traces both the personal and scientific trajectory of this unsung hero of the early days of high-energy physics and quantum field theory. A number of invited contributions by members of the Källén family and distinguished researchers from the field, all of them personally acquainted with Källén, combine to form an authentic portrait of the researcher and the man. Last but not least, the reader will become acquainted with some aspects of the history of particle physics in those days, as related by Källén and those who corresponded with him. A commented selection of his most important and not easily accessible papers is included as an added bonus for specialists. (shrink)

These lecture notes present a concise and introductory, yet as far as possible coherent, view of the main formalizations of quantum mechanics and of quantum field theories, their interrelations and their theoretical foundations. The "standard" formulation of quantum mechanics (involving the Hilbert space of pure states, self-adjoint operators as physical observables, and the probabilistic interpretation given by the Born rule) on one hand, and the path integral and functional integral representations of probabilities amplitudes on the other, are (...) the standard tools used in most applications of quantum theory in physics and chemistry. Yet, other mathematical representations of quantum mechanics sometimes allow better comprehension and justification of quantum theory. This text focuses on two of such representations: the algebraic formulation of quantum mechanics and the "quantum logic" approach. Last but not least, some emphasis will also be put on understanding the relation between quantum physics and special relativity through their common roots - causality, locality and reversibility, as well as on the relation between quantum theory, information theory, correlations and measurements, and quantum gravity. Quantum mechanics is probably the most successful physical theory ever proposed and despite huge experimental and technical progresses in over almost a century, it has never been seriously challenged by experiments. In addition, quantum information science ha s become an important and very active field in recent decades, further enriching the many facets of quantum physics. Yet, there is a strong revival of the discussions about the principles of quantum mechanics and its seemingly paradoxical aspects: sometimes the theory is portrayed as the unchallenged and dominant paradigm of modern physical sciences and technologies while sometimes it is considered a still mysterious and poorly understood theory, waiting for a revolution. This volume, addressing graduate students and seasoned researchers alike, aims to contribute to the reconciliation of these two facets of quantum mechanics. (shrink)

The AdS/CFT duality has been a source of several strong conceptual claims in the physics literature that have yet to be explored by philosophers. In this paper I focus on one of these: the extent to which spacetime geometry and locality can be said to emerge from this duality, so that neither is fundamental. I argue: that the kind of emergence in question is relatively weak, involving one kind of spacetime emerging from another kind of spacetime; inasmuch as there is (...) something conceptually interesting to say about the emergence of spacetime and locality , it is no different from that already well known to those within canonical quantum gravity; that at the core of AdS/CFT is an issue of representation and redundancy in representation. (shrink)

Recent developments in quantum theory have focused attention on fundamental questions, in particular on whether it might be necessary to modify quantum mechanics to reconcile quantum gravity and general relativity. This book is based on a conference held in Oxford in the spring of 1984 to discuss quantum gravity. It brings together contributors who examine different aspects of the problem, including the experimental support for quantum mechanics, its strange and apparently paradoxical features, (...) its underlying philosophy, and possible modifications to the theory. (shrink)

Features of consciousness difficult to understand in terms of conventional neuroscience have evoked application of quantum theory, which describes the fundamental behavior of matter and energy. In this paper we propose that aspects of quantum theory (e.g. quantum coherence) and of a newly proposed physical phenomenon of quantum wave function "self-collapse"(objective reduction: OR -Penrose, 1994) are essential for consciousness, and occur in cytoskeletal microtubules and other structures within each of the brain's neurons. The particular characteristics (...) of microtubules suitable for quantum effects include their crystal-like lattice structure, hollow inner core, organization of cell function and capacity for information processing. We envisage that conformational states of microtubule subunits (tubulins) are coupled to internal quantum events, and cooperatively interact (compute) with other tubulins. We further assume that macroscopic coherent superposition of quantum-coupled tubulin conformational states occurs throughout significant brain volumes and provides the global binding essential to consciousness. We equate the emergence of the microtubule quantum coherence with pre-conscious processing which grows (for up to 500 milliseconds) until the mass-energy difference among the separated states of tubulins reaches a threshold related to quantum gravity. According to the arguments for OR put forth in Penrose (1994), superpositioned states each have their own space-time geometries. When the degree of coherent mass-energy difference leads to sufficient separation of space-time geometry, the system must choose and decay (reduce, collapse) to a single universe state. In this way, a transient superposition of slightly differing space-time geometries persists until an abrupt quantum classical reduction occurs. Unlike the random, "subjective reduction"( SR, or R) of standard quantum theory caused by observation or environmental entanglement, the OR we propose in microtubules is a self-collapse and it results in particular patterns of microtubule-tubulin conformational states that regulate neuronal activities including synaptic functions. (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)

In conceptual debates involving the quantum gravity community, the literature discusses the so-called “emergence of space–time”. However, which interpretation of quantum mechanics (QM) could be coherent with such claim? We show that a modification of the Copenhagen Interpretation of QM is compatible with the claim that space–time is emergent for the macroscopic world of measurements. In other words, pure quantum states do not admit space–time properties until we measure them. We call this approach “Achronotopic” (ACT) Interpretation (...) of QM, which yields a simple and natural interpretation of the most puzzling aspects of QM, such as particle-wave duality, wave function collapse, entanglement, and quantum superposition. Our interpretation yields the same results in all measurements as the Copenhagen Interpretation, but provides clues toward the sub-Planckian physics. In particular, it suggests the non-existence of quantum gravity in the conventional sense understood as the quantization of a classical theory. (shrink)

Analogue Gravity Phenomenology is a collection of contributions that cover a vast range of areas in physics, ranging from surface wave propagation in fluids to nonlinear optics. The underlying common aspect of all these topics, and hence the main focus and perspective from which they are explained here, is the attempt to develop analogue models for gravitational systems. The original and main motivation of the field is the verification and study of Hawking radiation from a horizon: the enabling feature (...) is the possibility to generate horizons in the laboratory with a wide range of physical systems that involve a flow of one kind or another. The years around 2010 and onwards witnessed a sudden surge of experimental activity in this expanding field of research. However, building an expertise in analogue gravity requires the researcher to be equipped with a rather broad range of knowledge and interests. The aim of this book is to bring the reader up to date with the latest developments and provide the basic background required in order to appreciate the goals, difficulties and success stories in the field of analogue gravity. Each chapter of the book treats a different topic explained in detail by the major experts for each specific discipline. The first chapters give an overview of black hole spacetimes and Hawking radiation before moving on to describe the large variety of analogue spacetimes that have been proposed and are currently under investigation. This introductory part is then followed by an in-depth description of what are currently the three most promising analogue spacetime settings, namely surface waves in flowing fluids, acoustic oscillations in Bose-Einstein condensates and electromagnetic waves in nonlinear optics. Both theory and experimental endeavours are explained in detail. The final chapters refer to other aspects of analogue gravity beyond the study of Hawking radiation, such as Lorentz invariance violations and Brownian motion in curved spacetimes, before concluding with a return to the origins of the field and a description of the available observational evidence for horizons in astrophysical black holes. (shrink)

One of the most challenging and fascinating issue in mathematical and theoretical physics concerns the possibility of identifying the logic underlying the so-called quantum universe, i.e., Quantum Mechanics and Quantum Gravity. Besides the sheer difficulty of the problem, inherent in the actual formulation of Quantum Mechanics—and especially of Quantum Gravity—to be used for such a task, a crucial aspect lies in the identification of the appropriate axiomatic logical proposition calculus to be associated to (...) such theories. In this paper the issue of the validity of the conventional principle of non-contradiction is called into question and is investigated in the context of non-relativistic Quantum Mechanics. In the same framework a modified form of the principle, denoted as 3-way PNC is shown to apply, which relates the axioms of quantum logic with the physical requirements placed by the Heisenberg Indeterminacy Principle. (shrink)

[To be presented at PSA 2018] -/- The gauge/gravity duality and its relation to the possible emergence of gravity from quantum physics has been much discussed. Recently, however, Sebastian De Haro has argued that the very notion of a duality precludes emergence, given what he calls the internal view of dualities, on which the dual theories are physically equivalent. However, I argue that De Haro's argument for the internal view is not convincing, and we do not have (...) good reasons to adopt it. In turn, I propose we adopt the external view, on which dual theories are not physically equivalent, instead. (shrink)

continent. 1.1 (2011): 60-67. At the beginning of Martin Heidegger’s lecture “Time and Being,” presented to the University of Freiburg in 1962, he cautions against, it would seem, the requirement that philosophy make sense, or be necessarily responsible (Stambaugh, 1972). At that time Heidegger's project focused on thinking as thinking and in order to elucidate his ideas he drew comparisons between his project and two paintings by Paul Klee as well with a poem by Georg Trakl. In front of Klee's (...) Saints from the Window and Death of Fire —though we wouldn’t absolutely understand what we were seeing—he writes, “we should want to stand…a long while.” In a similar manner, of Trakl’s poem “Septet of Death”—although it is likely we are unsure in what we hear—Heidegger states that, “we should want to hear…[it] often.” Heidegger further states that in appreciating these, “we “should abandon any claim that [they] be immediately intelligible” (1). So also we must we approach, Heidegger continues, the realm of theoretical physics, in which the difficult work of Werner Heisenberg, be listened to “without protest” and without “any claim that he be immediately understood.” These works, like his own project, merit the time they take to be originally (mis)understood. But this is not necessarily true for philosophy, Heidegger advises, because, “That thinking is supposed to offer ‘worldly wisdom’ and perhaps even a ‘way to a blessed life’” (1). Philosophy is in the unique position of being both abstract (what do we talk about when we talk?) and at the same moment, useful. There are demands that it make sense, that it be, grounded, immediate, and most importantly, rational. Heidegger draws these comparisons between the works of Klee and Trakl and Heisenberg not to claim that philosophy is totally irresponsible. He does not claim that the poet, the painter, nor the physicist have acted irresponsibly. Rather, he would say, they are rising to the highest levels of intelligibility, though it is perhaps an intelligibility that is commonly unavailable to us. In Trakl’s case, as we shall see, mastery is the end result of difficult words. Instead, Heidegger seems be making pleas: for a period of uninterrupted unintelligibility (pure unintelligibility); and that there is a time (that time is now) when, “thinking is…placed in a position which demands of it reflections that are far removed from any useful, practical wisdom” (1-2). Heidegger argues that philosophy requires a period of time in which, instead of focusing on the practical—or even on the worldly—the discipline draw its “determination” instead from the place of painting and poetry and physics. In doing so, “we should have to abandon any claims to immediate intelligibility” (2). But Heidegger doesn’t offer this as a way out. We still have to turn up, we “still have to listen, because we must think what is inevitable, but preliminary” (2). The point for Heidegger, is not to listen to a series of propositions, but instead to “follow the movement of showing” (2). I. … Maybe we're here only to say: house, bridge, well, gate, jug, olive tree, window— at most: pillar, tower … but to say them, remember, oh, to say them in a way that the things themselves never dreamed of existing so intensely.… Rainer Maria Rilke, “The Ninth Elegy” There is little more fundamental, preliminary, in the world than language. We use language, in the form of speech, constantly, whether we are saying anything or not. “Man speaks,” Heidegger writes, and goes on to describe in his essay “Language” (2001) the constant speaking that we do. “We are always speaking, even when we do not utter a single word aloud, but merely listen or read, and even when we are not particularly speaking or listening but are attending to some work or taking a rest” (187). Speaking is expression, an utterance of something internal. It is a recognition of a world. It is a way of communicating thought and it is an activity that we all do, inevitably. Speaking separates the human from the animal world, and despite advances in primatology that seek to give ‘voice’ to primates and other non-human animals, it can safely be said that our form of communication—what we call speech and know as language—is the most advanced, the most complicated. We use it to present and represent the world around us; through actual utterances (vocalization) or through the written word or through ‘unvoiced thoughts’ and dreams. We use language, but more specifically speech—naming—to transmit moods, thoughts, desires, aversions, and feelings. These expressions, mere utterances, nearly always find a source in words, whether spoken or not. Heidegger writes that this common view of language means “that only speech enables man to be the living being he is as man. It is as the one who speaks that man is—man” (187). Speaking then—utterance—surrounds us constantly, whether in the form of careful thought—in the form of an academic paper, say—or in the half mutterings and forgotten thoughts of a nearly remembered dream. Like scaffolding, the apparatus of speech sustains and explains the world, making, in a sense, the world rational, making it apparent. When we speak, we describe, and in doing so, name the world. We use words, through this process of naming, to interpret and sustain the world we see, and the world we imagine. Like Rilke’s naming of jug, and bridge, and window, and stream, we describe—and inscribe upon—the world through an activity of naming. Are we here, perhaps, to name? Is it possible not to name? Is it possible to regard and to view and to look around without naming what we see? Is it possible to feel—to experience—world without giving utterance to that feeling, that process? Sadness, grief, joy, ecstasy, hunger, thirst. Desk, light, room, pen, book, world. White, black, tomorrow, today. Each of these words is a name given to a thing I see in front of me, or a concept that I imagine (in the case of tomorrow or world). What arises in my mind has already existed. If I imagine it, it is named. The word for ‘tomorrow’ and ‘desk’ and ‘light’ precedes me, and precedes my concept of it. The idea of it is already pre-informed, and I must, in a certain sense, bend my ideas to it. When I imagine a table, I imagine my own table (or I imagine an idea of table) but that imagining must follow certain general rules; while, perhaps, it might not always require four legs and a horizontal surface, it must, at least not be, say, a pool of water, or a pile of excrement. It must have some tableness to it to be a table. It must, with Heidegger, table. Otherwise, speech is reduced to gibberish. For Heidegger however, the discussion of language points to something deeper than its “scientific and analytic” study as a communicative device. Indeed, Heidegger seeks to understand language not in reference to man or woman, not as an utterance of humanity, but in reference to itself. In doing so he abandons the conversation—that is, he casts away the traditional arguments surrounding philosophy of language; that it is a means of expression; that it is a human activity; and that it is somehow a representation of something that is—in order to seek to understand language as language, on its own terms. Heidegger is not a philosopher of language, but a philosopher of world, of being. Despite these “correct ideas” holding sway “over the whole field of the varied scientific perspectives on language…they ignore completely the oldest natural cast of language” (191). What is this “oldest natural cast of language? It is the act of language itself. Language is language and language speaks. “Most often,” Heidegger writes, “and too often, we encounter what is spoken only as the residue of a speaking long past” (195). Speech, as we normally encounter it, is like Echo herself calling out to Narcissus, doomed to repeat what has already been said, a mere remnant of what was once language, a trace left behind in the gathering silence of becoming. In both the essay “Language” and in his three lecture course “The Nature of Language” (1982), Heidegger attempts to unpack the seeming tautology of language as language. In each, he focuses on poetry as a way out, or into, a true discussion of the oldest natural cast of language. Poetry is pure speech. In poetry, language is brought to language and language speaks ( Die Sprach spricht ). In the act of poetry, the act of pure speech, the poet names (on the surface not different from how I name this table, this computer) but in the poet naming, the naming does not “hand out titles,” “apply terms,” but rather the naming is a call, a calling forth of entities that bring them into their own, allow them to take their place purely, without compromise. This calling, Heidegger (2001) states, “here calls into a nearness. But even so the call does not wrest what it calls away from the remoteness, in which it is kept by the calling there. The calling calls into itself and therefor always here and there—here into presence, there into absence” (196). II. Window with falling snow is arrayed, Long tolls the vesper bell, The house is provided well, The table is for many laid. Wandering ones, more than a few, Come to the door on darksome courses. Golden blooms the tree of graces Drawing up the earth’s cool dew. Wanderer quietly steps within; Pain has turned the threshold to stone. There lie, in limpid brightness shown, Upon the table bread and wine. Georg Trakl “A Winter Evening” Heidegger is often given short shrift as an abysmally difficult writer, as one that makes no sense and is needlessly difficult. In doing this though, we forget sometimes his eloquence, his simple beauty in writing. Of the above opening stanza, “Window with falling snow is arrayed/ Long tolls the vesper bell.” he writes (2001), This speaking names the snow that soundlessly strikes the window late in the waning day, while the vesper bell rings. In such a snowfall, everything lasts longer. Therefore the vesper bell, which daily rings for a strictly fixed time, tolls long. The speaking names the winter evening time (197). The speaking names the winter evening time. It is almost impossible to comment on that one line by Heidegger. It is as though it must exist on its own completely, without elucidation—as though in front of it we must stand as we do in front of a painting by Klee, that is, we must abandon any claim . Silent and devoted. The speaking of the poem here is not clearly different from common speech ( rede ) yet there is, via Heidegger, an invitation to experience that auracular quality of light and stillness that a gentle, dusk tinged snowfall gives; words evoking a quality so clear, so poignant that, in a sense, Heidegger’s work, at this moment, has been done. But what does this naming accomplish? What does the call call? Remember, it is not the poet that calls, but the naming which calls. The poet has only brought the words forward; it is now the words— snow, vesper bell, window— that take new life in the pure language of the poem. Entities are called forth into presence, like the speaking that names the winter evening time. Not to be present amongst us now, however; naming ‘table’ in the poem does not place it in front of us in this room. Rather, the naming places entities into a gathering which is also a sheltering. The naming brings them to be. In an act of appropriation, things come to be purely as their own, unimpeded by a predetermined expectation. They are called to themselves into an arrival. In Being and Time (1962), Heidegger famously describes the movement between present-at-hand and ready-to-hand in his analysis of the hammer, and of equipment in general. This analysis is already known, if not always clear, to most readers of Heidegger. Briefly, a hammer is ordinarily zuhanden or ready-to-hand; it is part of the background of the world, equipment used and never thought about, like this desk, this sheet of paper, this room. Our interaction with it is temporary and it is historically different for each entity and each relation. We need a hammer, we use a hammer. If all goes according to plan, the hammer remains ready-to-hand; it remains, in a sense, undisclosed and certainly unobtrusive. Our world is undisturbed by the hammer. Only when the hammer or the car or the computer is broken (or sometimes unused or unrecognized or missing) does it intrude into our world, become conspicuous as an object present-at-hand, or vorhanden . In this case, we reach for the hammer, it is broken and we suddenly notice it’s being, broken though it is. The thing which was always ready to hand—handy—is suddenly abstract, something to be examined, if only in its absence or disfunction. This can be exhibited for all entities, and it is important to note that in this analysis the zuhanden / vorhanden split is not restricted to a specific form of constructed material; zuhanden does not refer to the car, and vorhanden the sunset. No entity is ever exclusively ready-to-hand or present-at-hand; they are instead, interpenetrated with each others mode of being, one informing the other in a way that both brings things forth into the world—discloses is the word Heidegger chooses—and at the same time conceals them. As one mode is coming to be so another mode is withdrawing. This flux and movement between modes is precisely what brings the world forward, and what makes it manifest. It exists beyond where we tread and before man took dubious control of the world. We go to find a book or turn on the computer and it is missing or broken and we become aware of the object, as though for the first time. We walk to the water to glimpse the sunset and miss it, or it is less than stellar; in the sunset’s grayness, we become aware of it’s being sunset. The thing is disclosed in its withdrawal. Echoing Heraclitus, we can say that as something is coming to be, it is already becoming something other. Of similar importance to the fact that things are never all of one, or all of the other, they are also never alone. The hammer is never a single object, but is in relation always to the whole. Heidegger (1962) states, Equipment—in accordance with its equipmentality—always is in terms of its belonging to other equipment: ink-stand, pen, ink, paper, blotting pad, table, lamp, furniture, windows, doors, room. These ‘Things’ never show themselves proximally as they are for themselves…What we encounter as closest to us…is the room; and we encounter it not as something ‘between four walls’ in a geometrical, spatial sense, but as equipment for residing…it is in this that any ‘individual’ item of equipment shows itself. Before its does so, a totality of equipment has already been discovered (97). Equipment resides—dwells—in its relations, in its proximal being to other beings. Within the structure of totality, a series of relations is always occurring. The hammer is on the workbench in the carpenter’s hand in the workshop in the village under the sky and under the sun. It doesn’t stop there. Equipment surrounds us and the focus is not on what it does, or what one does with it—the carpenter with the hammer, the writer with laptop—but with the fact that it is. Equipment occurs in relation and is always occurring around us overhead, underfoot, by the stream and in the city. There is a constant exchange of relations happening, and as this occurs, so the world occurs, so the world both discloses and withdraws, into and out of itself. In a very real sense, language is also equipment. It is the thing that we use most often without thought, it is ready-to-hand (except when it’s not.) As we re- cognize the world around us, as we offer names for things and make lists, we are using language much like we might use a hammer, that is, bluntly. Most of the time it is invisible and we draw on it without wondering how we are going to say something. When language does intrude, it does so in an awkward moment, that moment when we can’t remember the right word, when we forget a phrase. At that second, it “speaks itself as language,” it reveals itself as malfunctioning equipment, and we “undergo” an experience with language, in Heidegger’s famous formulation. Language is not a tool anymore that we use to bludgeon an object, but something instead that we submit to, that we experience. In “The Nature of Language,” Heidegger (1982) writes, But when does language speak to us as language? Curiously enough, when we cannot find the right word for something that concerns us, carries us away, oppresses or encourages us. Then we leave unspoken what we have in mind and, without rightly giving it a thought, undergo moments in which language itself has distantly and fleetingly touched us with its essential being (59). The poet’s words become themselves, become appropriate, only when they no longer function in the prosaic world; they instead intrude as they come to be. Language itself brings itself to language. Names, like the entities they indicate, are always becoming something else. As noted above, language, through the poet, has brought forth entities from words previously “known.” I thought that I knew snow, but through Trakl’s re- presentation of the word, language calls forth a new image of snow, indeed calls forth snow itself. The vesper bell tolls longer, the table is for many laid. In bringing forth things , language has brought the world to presence. In everyday naming, word occludes world, preventing, in its everydayness, its coming forth, its disclosing. But what is this world that word has been brought forth into? In the same way that language speaks, world worlds. World, left alone, un-interfered with, comes into itself. It worlds. Again, this sounds like a tautology, but it is essential to Heidegger’s thought (and in my mind is more of a “god killer” than Nietzsche.) One of the most overlooked (and under-appreciated) aspects of Heidegger is his later examination and enthusiasm for the “fourfold,” or the system through which things come to be, through which things thing in a world worlding. The fourfold is the interaction of earth and sky, mortals and gods. Things come to be in the interstices and gathering of the fourfold. The fourfold provides both a place of being, and a sheltering, a place to dwell. Heidegger writes that “the things that were named, thus called, gather to themselves sky and earth, mortals and divinities. The four are united primally in being toward one another, a fourfold.” The poet has called, through the act of pure naming, things to come forth. In the purity of the fourfold—that is, when that is all that there is, when there are no other distractions, definitions, things—entities themselves can come to be. It is important to note that Heidegger is not saying that there are four formal things in the world, autonomous entities unto themselves. He is not evoking a pre-Socratic formula as to what makes up the world; instead, the four mirror each other constantly. (Heidegger calls this the ‘mirror-play.’) They interpenetrate in the same way that the modes of being of things interpenetrate themselves. There is no discrete exclusivity in being or the fourfold. What makes up things is not a precise recipe of the four main components; what makes up things is the action of the fourfold coming together, the movement of the fourfold which is a becoming. Heidegger (2001) writes that “this gathering, assembling, letting stay is the thinging of things.” And he later adds that “thinging, things are things. Thinging, they gesture—gestate—world” (197). Language brings the world to be. It works not again as a recipe added to things, but instead it is a bridge, or more precisely, a relation. Language relates world to thing, brings world to thing. In a sense, it does not say anything; rather it allows, or calls in its movement. Heidegger (2001) writes that, The intimacy of world and thing is not a fusion. Intimacy obtains only where the intimate—world and thing—divides itself cleanly and remains separated. In the midst of the two, in the between of world and thing, in their inter, division prevails: a dif-ference (199). It is in this inter that language prevails. Language is difference, it is the differential aspect between world and thing that brings world to thing. In the final stanza of Trakl’s poem “The Winter Evening,” Trakl evokes this difference in the second line when he writes, “Pain has turned the threshold to stone.” Christopher Fynsk, in his essay “Noise at the Threshold,” draws attention to this point when he writes “it is the figure of the threshold that is language itself, inasmuch as language is defined as the articulation of difference by which difference comes about” (25). Language, as used in the pure language of the poem, draws together world and thing, bridging relation between entity and world. The calling of language calls world to thing, world to being. Heidegger (2001) describes this difference as unique; “of itself, it holds apart the middle in and through which world and things are at one with each other” (200). III. Neither reading nor writing, nor speaking—and yet it is by those paths that we escape what has been said already, and knowledge, and reciprocity, and enter the unknown space, the space of distress where what is given is perhaps not received by anyone (99). Maurice Blanchot The Writing of Disaster So far, we have allowed Heidegger to put forward what language does, how it functions as a relation and how it operates as a threshold, as a bridge. What interests me is what happens beyond language, beyond the relation. What happens to the thing without the naming, without the poet, or even without the everyday chatter—Fynsk calls this ‘noise’—intruding on being? If language allows things to become by bringing thing to world, what happens when we remove this bringing, this threshold turned to pain? In “The Nature of Language,” Heidegger examines the work of the poet Stefan George, specifically “The Word”: Wonder or dream from distant land I carried to my county’s strand And waited till the twilight norn Had found the name within her bourn— Then I could grasp it close and strong It blooms and shines now the front along… Once I returned from happy sail, I had a prize so rich and frail, She sought for long and tidings told: “No like of these depths unfold.” And straight it vanished from my hand, The treasure never graced my land… So I renounced and sadly see: Where word breaks off no thing may be. That final line, “Where word breaks off no thing may be” is evoked on nearly every page of Heidegger’s essay. It is the line to which he returns over and over and bears repeating. Where word breaks off no thing may be. Where naming ends, no thing. We can interpret this in two ways (at least.) Where word—naming—breaks off, then there is nothing . Or, as I choose to read it, where word breaks off no thing may be. In this I see a hint forward, a marker left behind by Heidegger. What could this look like? What does no thing look like? Like a zen koan ( there is no mirror ) it is as thrilling and horrifying as contemplating what preceded the Big Bang. Because language as naming wasn’t always here; we weren’t always here. One or maybe two aspects of the fourfold (depending on your view of gods) were not always here, and there is no guarantee that we will always be around. What then? Heidegger (1982) describes the landscape that the poet finds, “It names the realm into which the renunciation must enter: it names the call to enter into that relation between thing and word which has now been experienced” (65). The poet, in renouncing, allows for the “may be” of “where word breaks off no thing may be.” This “may be” becomes “a kind of imperative, a command which the poet follows, to keep it from then on.” No thing is lacking. Where word breaks off, there may be, a totality, a completion. If we place the emphasis on may be , we make it affirmative, make it positive. One allows it. No thing is where the word, that is the name, is lacking. If we remove then (if we can remove) the word, the name, than that is where no thing is, that is where no thing may blossom, enrich, belong, become. What is no thing? Heidegger writes that “thing is anything that in any way is.” And just after this he writes that the “world alone gives being to the thing.” But what happens if there is no word? Word, in this formulation can be seen as an enframing, a challenging of language. By naming, by drawing a perimeter around an object, we hold it, by its definition (that is a brick) to an ordered future. If we borrow from Heidegger’s essay “The Question Concerning Technology” (1993) the idea of this standing-reserve of an ordered future, we see that “everywhere everything is ordered to stand by, to be immediately on hand, indeed to stand there just so that it may be on call for a further ordering” (322). What happens if there is no naming of the thing? Silence perhaps. Stillness. We can name—and do name—that which we know. We equate knowledge with knowing the name of something. A brick is a brick, a hammer is a hammer, the universe is the universe. By naming a thing, we create, and draw its parameters, the parameters of the thing, not as thing thinging in the fourfold, but as blunt object apparent. In the four dimensions relatively available to us, we observe (and name) that the brick takes up possibly six by four by two inches and is, in the sense that it currently occupies this time slot. It fulfills its destiny, its being, its brickness, it bricks . But what happens when we remove the name for this brick. We no longer know what to call this no-thing (if indeed we can even arrive at the point of uncalled calling.) In fact the it (this brick) is no longer a thing in the sense that by not naming—by removing the name—it still occupies the same dimension but is indiscernible from the world. It simply is , un-reliant, un- needed by me. By removing the subject (me) from it (the brick) do I not then also remove the object—or at least the duality objectifying it? Why is this important? Why does this matter? I have not really removed anything. I have not changed any thing , per se . The brick still occupies the same space in geographic and temporal dimensions. I have literally not even touched the brick sitting on my desk. But what I have done is removed the name, removed the word (the bridge, according to Heidegger) and in this (again, if this is even possible) there is something vertiginously liberating, not only for me (and my way of thinking) but also for the brick itself. Like the poet who calls the thing forward, by refusing to name, by avoiding any thing that demands me to name it, I release the thing into the fourfold. I am no longer challenging the thing to be there for me ; I do not en frame it through language. Rather I, in an act of extreme responsibility, am refusing the challenge. By refusing the name (refusing to name) one allows, (or no one allows no thing) the brick to be all things , to manifest its manifold being, to incorporate all things into its thinging . It becomes, quite literally, every thing . Because, in its infinite manifestness, it incorporates everything; the mud that gave it its current being, the water that formed the mud, the sun, the stars, the universe and it also allows it to become mud again, to become landfill, to become again, water and sun and stars and universe in an endless, infinite cycle of coming to be some thing (else). Perhaps this is what Heidegger is suggesting when he talks about the stillness at the end of his essay, “Language” (2001): The dif-ference stills particularly in two ways: it stills the things in thinging and the world in worlding. Thus stilled, thing and world never escape from the dif-ference. Rather, they rescue it in the stilling, where the dif-ference is itself the stillness (206). It is in this stillness that I can imagine a gellasenheit (here I mean both “releasement in the Heideggarean sense, as well as Meister Eckhart’s use of the term meaning “letting the world go and giving oneself to God”) of thing and world, a releasing into the stillness and silence of no thing beyond where word breaks off. It is here where I may no longer be, and yet no thing is, but may be. (shrink)

Research in quantum gravity strongly suggests that our world in not fundamentally spatiotemporal, but that spacetime may only emerge in some sense from a non-spatiotemporal structure, as this paper illustrates in the case of causal set theory and loop quantum gravity. This would raise philosophical concerns regarding the empirical coherence and general adequacy of theories in quantum gravity. If it can be established, however, that spacetime emerges in the appropriate circumstances and how all its (...) relevant aspects are explained in fundamental non-spatiotemporal terms, then the challenge is fully met. It is argued that a form of spacetime functionalism offers the most promising template for this project. (shrink)

Some aspects of the Schrödinger equation in quantum field theory are considered in this article. The emphasis is on the Schrödinger functional equation for Yang-Mills theory, arising mainly out of Feynman's work on (2+1)-dimensional Yang-Mills theory, which he studied with a view to explaining the confinement of gluons. The author extended Feynman's work in two earlier papers, and the present article is partly a review of Feynman's and the author's work and some further extension of the latter. The (...) primary motivation of this article is to suggest that considering the Schrödinger functional equation in the context of Yang-Mills theory may contribute significantly to the solution of the confinement and related problems, an aspect which, in the author's opinion, has not received the attention it deserves. The relation of this problem with certain others such as those of quarks, superconductivity, and quantum gravity is considered briefly, together with certain basic aspects of the formalism that may be of interest in their own right, especially for the beginner. (shrink)

The various physical aspects of the general relativistic principles of covariance and strong equivalence are discussed, and their mathematical formulations are analyzed. All these aspects are shown to be present in classical general relativity, although no contemporary formulation of canonical or covariant quantum gravity has succeeded to incorporate them all. This has, in part, motivated the recent introduction of a geometro-stochastic framework for quantum general relativity, in which the classical frame bundles that underlie the formulation (...) of parallel transport in classical general relativity are replaced by quantum frame bundles. It is shown that quantum frames can take over the role played by complete sets of observables in conventional quantum theory, so that they can mediate the natural transference of the general covariance and the strong equivalence principles from the classical to the quantum general relativistic regime. This results in a geometrostochastic mode of quantum propagation in general relativistic quantum bundles, which is mathematically implemented by path integration methods based on parallel transport along horizontal lifts of geodesics for the vacuum expectation values of a quantum gravitational field in a quantum spacetime supermanifold. The covariance features of this field are embedded in a quantum gravitational supergroup, which incorporates Poincaré as well as diffeomorphism invariance, and resolves the issue of time in quantum gravity. (shrink)

Metaphysics of Quantum Gravity The metaphysics of quantum gravity explores metaphysical issues related to research programs in theoretical physics clustered under the term quantum gravity. These research programs aim at the formulation of a theory that reconciles the theory of general relativity with quantum theory. The goal is not necessarily to come up with a … Continue reading Metaphysics of Quantum Gravity →.

This paper engages with the following closely related questions that have recently received some attention in the literature: what is the status of the equivalence principle in general relativity?; how does the metric field obtain its property of being able to act as a metric?; and is the metric of GR derivative on the dynamics of the matter fields? The paper attempts to complement these debates by studying the spin-2 approach to gravity. In particular, the paper argues that three (...) lessons can be drawn from the spin-2 approach: different from what is sometimes claimed in the literature, central aspects of the non-linear theory of GR are already derivable in classical spin-2 theory; in particular, ‘universal coupling’ can be considered a derived ‘theorem’ in both the classical and the quantum spin-2 approach; this provides new insights for the investigation of the equivalence principle; the ‘second miracle’ that Read et al. argue characterises GR is explained in the classical as well as in the quantum version of the spin-2 approach; the spin-2 approach allows for an ontological reduction of the metrical part of spacetime to the dynamics of matter fields. (shrink)

Prevailing theories of consciousness may be characterized as either a physicalist view of mind with material building blocks that grow in complexity unto an emergent conscious experience, or as a dualistic model in which mind-body interaction is taken as the interface of conscious intent and unconscious bodily processing. Roger Penrose supports a model of consciousness that goes beyond dualism by adding a third domain [19]. The Three World model describes interconnected yet independent aspects of consciousness: Physical, Mental & Platonic. (...) These three worlds are grounded in the three axioms of quantum mechanics: measurement, superposition and entanglement. The Mental World corresponds to the superposition principle in which all possible future realities are superposed as potentials before a choice is made. The superposition is analogous to the choices we make everyday. In the Physical World, the measurement principles states that the quantum system must collapse the superposed possibilities into a single actuality. The most peculiar phenomenon in quantum mechanics is entanglement. Quantum systems may be entangled in a timeless and spaceless way such that they will still be connected despite separation in space or time. The Platonic World is akin to entanglement, because mathematics and conceptual forms are unchanging regardless of space or time. Finally, a new model called Fractal Trialism is proposed which describes how there is a nested trialism within each of the three worlds in order to elaborate their interconnectedness. This model describes digital computers, quantum computers and shared experience. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}. (shrink)

The central thesis of this paper is that contemporary theoretical physics is grounded in philosophical presuppositions that make it difficult to effectively address the problems of subject-object interaction and discontinuity inherent to quantum gravity. The core objectivist assumption implicit in relativity theory and quantum mechanics is uncovered and we see that, in string theory, this assumption leads into contradiction. To address this challenge, a new philosophical foundation is proposed based on the phenomenology of Maurice Merleau-Ponty and Martin (...) Heidegger. Then, through the application of qualitative topology and hypernumbers, phenomenological ideas about space, time, and dimension are brought into focus so as to provide specific solutions to the problems of force-field generation and unification. The phenomenological string theory that results speaks to the inconclusiveness of conventional string theory and resolves its core contradiction. (shrink)

The quest for a theory of quantum gravity is usually understood to be driven by philosophical assumptions external to physics proper. It is suspected that specifically approaches in the context of particle physics are rather based on metaphysical premises than experimental data or physical arguments. I disagree. In this paper, I argue that the quest for a theory of quantum gravity sets an important example of physics’ internal unificatory practice. It is exactly Weinberg’s and others’ particle (...) physics stance that reveals the issue of quantum gravity as a genuine physical problem arising within the framework of quantum field theory. (shrink)

'Holographic' relations between theories have become a main theme in quantum gravity research. These relations entail that a theory without gravity is equivalent to a gravitational theory with an extra spatial dimension. The idea of holography was first proposed in 1993 by Gerard 't Hooft on the basis of his studies of evaporating black holes. Soon afterwards the holographic 'AdS/CFT' duality was introduced, which since has been heavily studied in the string theory community and beyond. Recently, Erik (...) Verlinde has proposed that even Newton's law of gravitation can be related holographically to the thermodynamics of information on screens. We discuss inter-theoretical relations in these scenarios: what is the status of the holographic relation in them and in what sense is gravity, or spacetime, emergent? (shrink)

It has been suggested in the literature that spatial coherence of the wave function can be dynamically suppressed by fluctuations in the spacetime geometry. These fluctuations represent the minimal uncertainty that is present when one probes spacetime geometry with a quantum probe. Two similar models have been proposed, one by Diósi and one by Karolyhazy and collaborators, based on apparently unrelated minimal spacetime bounds. The two models arrive at somewhat different expressions for the dependence of the localization coherence length (...) on the mass and size of the quantum object. In the present article we compare and contrast the two models from three aspects: comparison of the spacetime bounds, method of calculating decoherence time, comparison of noise correlation. We show that under certain conditions the minimal spacetime bounds in the two models can be derived one from the other. We argue that the methods of calculating the decoherence time are equivalent. We re-derive the two-point correlation for the fluctuation potential in the K-model, and confirm the earlier result of Diósi and Lukács that it is non-white noise, unlike in the D-model, where the corresponding correlation is white noise in time. This seems to be the origin of the different results in the two models. We derive the non-Markovian master equation for the K-model. We argue that the minimal spacetime bound cannot predict the noise correlation uniquely, and additional criteria are necessary to accurately determine the effects of gravitationally induced decoherence. (shrink)

We consider a theory in which spacetime is a 4-dimensional manifold V4 embedded in an N-dimensional space VN. The dynamics is given by a first-order action which is a straightforward generalization of the well-known Nambu-Gotto string action. Instead of the latter action we then consider an equivalent action, a generalization of the Howe-Tucker action, which is a functional of the (extrinsic) embedding variables ηa(x) and of the (intrinsic) induced metric gυv (x) on V4. In the quantized theory we can define (...) an effective action by means of the Feynman path integral in which we functionally integrate over the embedding variables. What remains is functionally dependent solely on the induced metric. It is well known that the effective action so obtained contains the Ricci scalar R and its higher orders. But due to our special choice of a quantity, the so-called “matter” density ω(η) in VN entering the original first-order action, it turns out that the effective action contains also the source term. The latter is in general that of a p-dimensional membrane (p-brane). In particular we consider the case of bosonic point particles. Finally we discuss and clarify certain interpretational aspects of quantum mechanics from the viewpoint of our embedding model. (shrink)

A number of recent theories of quantum gravity lack a one-dimensional structure of ordered temporal instants. Instead, according to many of these views, our world is either best represented as a single three-dimensional object, or as a configuration space composed of such three-dimensional objects, none of which bear temporal relations to one another. Such theories will be empirically self-refuting unless they can accommodate the existence of conscious beings capable of representation. For if representation itself is impossible in a (...) timeless world, then no being in such a world could entertain the thought that a timeless theory is true, let alone believe such a theory or rationally believe it. This paper investigates the options for understanding representation in a three-dimensional, timeless, world. Ultimately it concludes that the only viable option is one according to which representation is taken to be deeply non-naturalistic. Ironically then we are left with two seemingly very unattractive options. Either a very naturalistic motivation—taking seriously a live view in fundamental physics—leads us to a very non-naturalistic view of the mental, or else views in the philosophy of mind partly dictate what is an acceptable theory in physics. (shrink)

Quantum field theory provides the framework for many fundamental theories in modern physics, and over the last few years there has been growing interest in its historical and philosophical foundations. This anthology on the foundations of QFT brings together 15 essays by well-known researchers in physics, the philosophy of physics, and analytic philosophy.Many of these essays were first presented as papers at the conference?Ontological Aspects of Quantum Field Theory?, held at the Zentrum fr interdisziplin„re Forschung, Bielefeld, Germany. (...) The essays contain cutting-edge work on ontological aspects of QFT, including: the role of measurement and experimental evidence, corpuscular versus field-theoretic interpretations of QFT, the interpretation of gauge symmetry, and localization.This book is ideally suited to anyone with an interest in the foundations of quantum physics, including physicists, philosophers and historians of physics, as well as general readers interested in philosophy or science. (shrink)

In the author’s previous contribution to this journal (Rosen 2015), a phenomenological string theory was proposed based on qualitative topology and hypercomplex numbers. The current paper takes this further by delving into the ancient Chinese origin of phenomenological string theory. First, we discover a connection between the Klein bottle, which is crucial to the theory, and the Ho-t’u, a Chinese number archetype central to Taoist cosmology. The two structures are seen to mirror each other in expressing the psychophysical (phenomenological) action (...) pattern at the heart of microphysics. But tackling the question of quantum gravity requires that a whole family of topological dimensions be brought into play. What we find in engaging with these structures is a closely related family of Taoist forebears that, in concert with their successors, provide a blueprint for cosmic evolution. Whereas conventional string theory accounts for the generation of nature’s fundamental forces via a notion of symmetry breaking that is essentially static and thus unable to explain cosmogony successfully, phenomenological/Taoist string theory entails the dialectical interplay of symmetry and asymmetry inherent in the principle of synsymmetry. This dynamic concept of cosmic change is elaborated on in the three concluding sections of the paper. Here, a detailed analysis of cosmogony is offered, first in terms of the theory of dimensional development and its Taoist (yin-yang) counterpart, then in terms of the evolution of the elemental force particles through cycles of expansion and contraction in a spiraling universe. The paper closes by considering the role of the analyst per se in the further evolution of the cosmos. (shrink)

Despite its long history and stunning experimental successes, the mathematical foundation of perturbative quantum field theory is still a subject of ongoing research. This book aims at presenting some of the most recent advances in the field, and at reflecting the diversity of approaches and tools invented and currently employed. Both leading experts and comparative newcomers to the field present their latest findings, helping readers to gain a better understanding of not only quantum but also classical field theories. (...) Though the book offers a valuable resource for mathematicians and physicists alike, the focus is more on mathematical developments. This volume consists of four parts: The first Part covers local aspects of perturbative quantum field theory, with an emphasis on the axiomatization of the algebra behind the operator product expansion. The second Part highlights Chern-Simons gauge theories, while the third examines (semi-)classical field theories. In closing, Part 4 addresses factorization homology and factorization algebras. (shrink)