Institute of Theoretical Physics, Exact Sciences Sidlerstrasse 5, University of Bern, CH-3012 Bern Switzerland portmann{at}itp.unibe.ch' + u + '@' + d + ''//--> awuethr{at}itp.unibe.ch' + u + '@' + d + ''//--> John Bell showed that a big class of local hidden-variable models stands in conflict with quantum mechanics and experiment. Recently, there were suggestions that empirically adequate hidden-variable models might exist which presuppose a weaker notion of local causality. We will show that a Bell-type inequality can be derived also (...) from these weaker assumptions. Introduction The EPR-Bohm experiment Local causality Bell's inequality from separate common causes 4.1 A weak screening-off principle 4.2 Perfect correlation and ‘determinism’ 4.3 A minimal theory for spins 4.4 No conspiracy Discussion. (shrink)

I give a brief introduction to how Feynman diagrams are used. I review arguments to the effect that they are only used as calculation tools and should not be interpreted as representations of physical processes. Against these arguments, I propose to regard Feynman diagrams as visual models that explain, in some respects, how elementary particles interact.

In 1949, Richard Feynman published the essentials of his solution to the recalcitrant problems that plagued quantum theories of electrodynamics of his days. The main problem was that the theory, that was considered to be correct and often led to correct observable consequences, also implied that some quantities should be infinite, while by common sense or empirical evidence they were finite. Feynman devised a method of solving the relevant theoretical equations in which particular combinations of elementary solutions yielded empirically adequate (...) results even when applied to complex problems. The combination of the basic solutions was guided by relatively simple graphical considerations... (shrink)

I reconstruct the discovery of the Higgs boson by the ATLAS collaboration at CERN as the application of a series of inferences from effects to causes. I show to what extent such diagnostic causal inferences can be based on well established knowledge gained in previous experiments. To this extent, causal reasoning can be used to infer the existence of entities, rather than just causal relationships between them. The resulting account relies on the principle of causality, attributes only a heuristic role (...) to the theory’s predictions, and shows how, and to what extent, data selection can be used to exclude alternative causes, even “unconceived” ones. (shrink)

A fair amount of recent scholarship has been concerned with correcting a supposedly wrong, but wide-spread, assessment of the consequences of the empirical falsification of Bell-type inequalities. In particular, it has been claimed that Bell-type inequalities follow from “locality tout court” without additional assumptions such as “realism” or “hidden variables”. However, this line of reasoning conflates restrictions on the spatio-temporal relation between causes and their effects (“locality”) and the assumption of a cause for every event (“causality”). It thus fails to (...) recognize a substantial restriction of the class of theories that is falsified through Bell-type inequalities. (shrink)

Arguably, the development of Feynman diagrams not only resulted in a useful tool for calculations but also brought about deep conceptual changes in the theory of quantum electrodynamics. Starting from this thesis, I try to bring to the fore a particular aspect of it. I maintain that the function of Feynman diagrams is not exhausted by their use in the application of the finished theory to concrete cases. Rather, Feynman diagrams are one of the results of Feynman's more general search (...) for appropriate means of representation. Accordingly, the development of Feynman diagrams is a characteristic example of Feynman's heuristics. (shrink)

I present first results of my analysis of a collection of about 24,000 email messages from internal mailing lists of the ATLAS collaboration, at CERN, the particle physics laboratory, during the years 2010–2013. I represent the communication on these mailing lists as a network in which the members of the collaboration are connected if they reply to each other’s messages. Such a network allows me to characterize the collaboration from a bird’s eye view of its communication structure in epistemically relevant (...) terms. I propose to interpret established measures such as the density of the network as indicators for the degree of “collaborativeness” of the collaboration and the presence of “communities” as a sign of cognitive division of labor. Similar methods have been used in philosophical and historical studies of collective knowledge generation but mostly at the level of information exchange, cooperation and competition _between_ individual researchers or small groups. The present article aims to take initial steps towards a transfer of these methods and bring them to bear on the processes of collaboration _inside_ a “collective author.”. (shrink)

In this note, I briefly review Lyre's analysis and interpretation of the Higgs mechanism. Contrary to Lyre, I maintain that, on the proper understanding of the term, the Higgs mechanism refers to a physical process in the course of which gauge bosons acquire a mass. Since also Lyre's worries about imaginary masses can be dismissed, a realistic interpretation of the Higgs mechanism seems viable.

John Bell showed that a big class of local hidden-variable models stands in conflict with quantum mechanics and experiment. Recently, there were suggestions that empirically adequate hidden-variable models might exist which presuppose a weaker notion of local causality. We will show that a Bell-type inequality can be derived also from these weaker assumptions.

This white paper outlines the plans of the History Philosophy Culture Working Group of the Next Generation Event Horizon Telescope Collaboration.

In the light of recent discussions we present the main results of our project, the aim of which was to derive a Bell-type inequality from the weakest possible assumptions. A principal outcome of the project is that a Bell-type inequality can be derived from the assumption of separate common causes (Graßhoff, Portmann and Wüthrich 2005), even without the assumption of perfectly anticorrelating event types (Portmann and Wüthrich 2007). We also address the critique that in Graßhoff et al. (2005) we implicitly (...) assume a common common cause (Hofer-Szabó forthcoming). (shrink)

I give a response to Adrian Wüthrich’s critical review of my analysis of the Higgs mechanism, in which I try to clarify some possible misunderstandings. I concede that, as Wüthrich points out, many physicists see the Higgs mechanism as the roll-over from a symmetrical potential in the initial Lagrangian to a symmetry-breaking potential, while my former analysis had basically focused on the gauge-invariant transformation of the initial Lagrangian into the intended form. My main contention, however, still is that neither (...) Higgs story has (as yet) much explanatory power. (shrink)

Feynman diagrams: conceptual tools for theoretical physicists Content Type Journal Article Category Book Review Pages 1-4 DOI 10.1007/s11016-011-9580-y Authors Laurie M. Brown, Department of Physics and Astronomy, Northwestern University, Evanston, IL 60201, USA Journal Metascience Online ISSN 1467-9981 Print ISSN 0815-0796.

Philosophy Beyond Spacetime assesses the state of play in the philosophy of quantum gravity. Research in this field aims at a unified theory in which quantum matter is related dynamically to relativistic spacetime. This volume highlights the conceptual questions involved, showing how physics and metaphysics can illuminate each other.

Spacetime as we know and love it is lost in most approaches to quantum gravity. For many of these approaches, as inchoate and incomplete as they may be, one of the main challenges is to relate what they take to be the fundamental non-spatiotemporal structure of the world back to the classical spacetime of GR. The present essay investigates how spacetime is lost and how it may be regained in one major approach to quantum gravity, loop quantum gravity.

ABSTRACT Unlike the relativity theory it seeks to replace, causal set theory has been interpreted to leave space for a substantive, though perhaps ‘localized’, form of ‘becoming’. The possibility of fundamental becoming is nourished by the fact that the analogue of Stein’s theorem from special relativity does not hold in CST. Despite this, we find that in many ways, the debate concerning becoming parallels the well-rehearsed lines it follows in the domain of relativity. We present, however, some new twists and (...) challenges. In particular, we show that a novel and exotic notion of becoming is compatible with causal sets. In contrast to the localized becoming considered compatible with the dynamics of CST by its advocates, our novel kind of becoming, while not answering to the typical A-theoretic demands, is global and objective. _1_ Introduction _2_ The Basics of Causal Set Theory _3_ Facing the Same Dilemma? _4_ Taking Growth Seriously _5_ Conclusion. (shrink)

This is a chapter of the planned monograph "Out of Nowhere: The Emergence of Spacetime in Quantum Theories of Gravity", co-authored by Nick Huggett and Christian Wüthrich and under contract with Oxford University Press. (More information at www<dot>beyondspacetime<dot>net.) This chapter introduces causal set theory and identifies and articulates a 'problem of space' in this theory.

Inspired by the writings of J. M. Hinton (1967a, 1967b, 1973), but ushered into the mainstream by Paul Snowdon (1980–1, 1990–1), John McDowell (1982, 1986), and M. G. F. Martin (2002, 2004, 2006), disjunctivism is currently discussed, advocated, and opposed in the philosophy of perception, the theory of knowledge, the theory of practical reason, and the philosophy of action. But what is disjunctivism?

This dictionary, the first dedicated to the work of Gilles Deleuze, offers an in-depth and lucid introduction to one of the most influential figures in continental philosophy. It defines and contextualizes more than 150 terms relating to Deleuze's philosophy, including "becoming," "body without organs," "deterritorialization," "difference," "repetition," and "rhizome." The entries also explore Deleuze's intellectual influences and the ways in which his ideas have shaped philosophy, feminism, cinema studies, postcolonial theory, geography, and cultural studies. More than just defining and describing (...) specific terms, the dictionary elaborates on Deleuze's ideas to reveal the varied applications of his philosophy. The contributors, who include some of the most prominent Deleuze scholars, bring their expert knowledge and critical opinion to bear on the entries. Their work provides a range of theoretical, historical, and aesthetic contexts for anyone interested in Deleuzian thought. Contributors include: Ronald Bogue, University of Georgia; Rosi Braidotti, Utrecht University; Claire Colebrook, University of Edinburgh; Tom Conley, Harvard University; Eugene Holland, Ohio State University; Tamsin Lorraine, Swarthmore College; Paul Patton, University of New South Wales; Kenneth Surin, Duke University; Alberto Toscano, Goldsmiths College. (shrink)

Recent epistemology has reflected a growing interest in issues about the value of knowledge and the values informing epistemic appraisal. Is knowledge more valuable that merely true belief or even justified true belief? Is truth the central value informing epistemic appraisal or do other values enter the picture? Epistemic Value is a collection of previously unpublished articles on such issues by leading philosophers in the field. It will stimulate discussion of the nature of knowledge and of directions that might be (...) taken by the theory of knowledge. The contributors are Jason Baehr, Michael Brady, Berit Brogaard, Michael DePaul, Pascal Engel, Catherine Elgin, Alvin Goldman, John Greco, Stephen Grimm, Ward Jones, Martin Kusch, Jonathan Kvanvig, Michael Lynch, Erik Olsson, Wayne Riggs and Matthew Weiner. (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)

Recent epistemology has reflected a growing interest in issues about the value of knowledge and the values informing epistemic appraisal. Is knowledge more valuable that merely true belief or even justified true belief? Is truth the central value informing epistemic appraisal or do other values enter the picture? Epistemic Value is a collection of previously unpublished articles on such issues by leading philosophers in the field. It will stimulate discussion of the nature of knowledge and of directions that might be (...) taken by the theory of knowledge. The contributors are Jason Baehr, Michael Brady, Berit Brogaard, Michael DePaul, Pascal Engel, Catherine Elgin, Alvin Goldman, John Greco, Stephen Grimm, Ward Jones, Martin Kusch, Jonathan Kvanvig, Michael Lynch, Erik Olsson, Wayne Riggs and Matthew Weiner. (shrink)

Defining ‘presentism’ in a way that saves it from being trivially false yet metaphysically substantively distinct from eternalism is no mean feat, as the first part of this collection testifies. In Wuthrich (forthcoming), I have offered an attempt to achieve just this, arguing that this is best done in the context of modern spacetime theories. Here, I shall refrain from going through all the motions again and simply state the characterization of an ersatzist version of presentism as it has (...) emerged from considerations there. Any acceptable formulation of presentism should remain neutral among competing spacetime theories in order to enable the present project of assessing the compatibility of presentism with various theories of modern physics, including both spacetime theories and theories of physical processes situated in a spatiotemporal setting. (shrink)

A Brief History of the Philosophy of Time is a concise and accessible survey of the history of philosophical and scientific developments in understanding time and our experience of time. It discusses prominent ideas about the nature of time, plus many subsidiary puzzles about time, from the classical period through the present.

This paper is an enquiry into the logical, metaphysical, and physical possibility of time travel understood in the sense of the existence of closed worldlines that can be traced out by physical objects. We argue that none of the purported paradoxes rule out time travel either on grounds of logic or metaphysics. More relevantly, modern spacetime theories such as general relativity seem to permit models that feature closed worldlines. We discuss, in the context of Gödel's infamous argument for the ideality (...) of time based on his eponymous spacetime, what this apparent physical possibility of time travel means. Furthermore, we review the recent literature on so-called time machines, i.e., of devices that produce closed worldlines where none would have existed otherwise. Finally, we investigate what the implications of the quantum behaviour of matter for the possibility of time travel might be and explicate in what sense time travel might be possible according to leading contenders for full quantum theories of gravity such as string theory and loop quantum gravity. (shrink)

Approaches to quantum gravity often involve the disappearance of space and time at the fundamental level. The metaphysical consequences of this disappearance are profound, as is illustrated with David Lewis's analysis of modality. As Lewis's possible worlds are unified by the spatiotemporal relations among their parts, the non-fundamentality of spacetime---if borne out---suggests a serious problem for his analysis: his pluriverse, for all its ontological abundance, does not contain our world. Although the mere existence---as opposed to the fundamentality---of spacetime must be (...) recovered from the fundamental structure in order to guarantee the empirical coherence of the non-spatiotemporal fundamental theory, it does not suffice to salvage Lewis's theory of modality from the charge of rendering our actual world impossible. (shrink)

Information theory presupposes the notion of an epistemic agent, such as a scientist or an idealized human. Despite that, information theory is increasingly invoked by physicists concerned with fundamental physics, physics at very high energies, or generally with the physics of situations in which even idealized epistemic agents cannot exist. In this paper, I shall try to determine the extent to which the application of information theory in those contexts is legitimate. I will illustrate my considerations using the case of (...) black hole thermodynamics and Bekenstein's celebrated argument for his formula for the entropy of black holes. This example is particularly pertinent to the theme of the present collection because it is widely accepted as `empirical data' in notoriously empirically deprived quantum gravity, even though the laws of black hole thermodynamics have so far evaded direct empirical confirmation. (shrink)

Does the need to find a quantum theory of gravity imply that the gravitational field must be quantized? Physicists working in quantum gravity routinely assume an affirmative answer, often without being aware of the metaphysical commitments that tend to underlie this assumption. The ambition of this article is to probe these commitments and to analyze some recently adduced arguments pertinent to the issue of quantization. While there exist good reasons to quantize gravity, as this analysis will show, alternative approaches to (...) gravity challenge the received wisdom. These renegade approaches do not regard gravity as a fundamental force, but rather as effective, i.e. as merely supervening on fundamental physics. I will urge that these alternative accounts at least prove the tenability of an opposition to quantization. (shrink)

Aesthetics is thought of as not only a theory of art or beauty, but also includes sensibility, experience, judgment, and relationships. This paper is a study of Bernard Stiegler’s notion of Aesthetic War (stasis) and symbolic misery. Symbolic violence is ensued through a loss of individuation and participation in the creation of symbols. As a struggle between market values against spirit values human life and consciousness within neoliberal hyperindustrial society has become calculable, which prevents people from creating affective and meaningful (...) attachments to symbols in relation to our retentional apparatuses, technology and memory. Such tension can be thought of as a dissonance between overlapping domains of social life, private and public. New Media is a reflection of aesthetic dissonance, an experience such as being bored and entertained at the same time, between antagonistic experiences, values, and behavior. Moreover, new media is at once a medium of customizing aesthetic experience individually as well as the threat and practice of prioritizing calculability and modeling of consumer behavior in favor of capitalistic effectiveness, which results in the simultaneous categorization of an individual as a data point, putting those who do not fit an algorithm’s premises at a disadvantage. (shrink)

Historical sciences like paleontology and archaeology have uncovered unimagined, remarkable and mysterious worlds in the deep past. How should we understand the success of these sciences? What is the relationship between knowledge and history? In Scientific Knowledge and the Deep Past: History Matters, Adrian Currie examines recent paleontological work on the great changes that occurred during the Cretaceous period - the emergence of flowering plants, the splitting of the mega-continent Gondwana, and the eventual fall of the dinosaurs - to (...) analyse the knowledge of historical scientists, and to reflect upon the nature of history. He argues that distinctively historical processes are 'peculiar': they have the capacity to generate their own highly specific dynamics and rules. This peculiarity, Currie argues, also explains the historian's interest in narratives and stories: the contingency, complexity and peculiarity of the past demands a narrative treatment. Overall, Currie argues that history matters for knowledge. (shrink)

The character of computational modelling of cognition depends on an underlying theory of representation. Classical cognitive science has exploited the syntax/semantics theory of representation that derives from logic. But this has had the consequence that the kind of psychological explanation supported by classical cognitive science is " _conceptualist_: " psychological phenomena are modelled in terms of relations that hold between concepts, and between the sensors/effectors and concepts. This kind of explanation is inappropriate for the Proper Treatment of Connectionism.

Kuhn claimed that several algorithms can be defended to select the best theory based on epistemic values such as simplicity, accuracy, and fruitfulness. In a recent paper, Okasha :83–115, 2011) argued that no theory choice algorithm exists which satisfies a set of intuitively compelling conditions that Arrow had proposed for a consistent aggregation of individual preference orderings. In this paper, we put forward a solution to avoid this impossibility result. Based on previous work by Gaertner and Xu, we suggest to (...) view the theory choice problem in a cardinal context and to use a general scoring function defined over a set of qualitative verdicts for every epistemic value. This aggregation method yields a complete and transitive ranking and the rule satisfies all Arrovian conditions appropriately reformulated within a cardinal setting. We also propose methods that capture the aggregation across different scientists. (shrink)

Theories of quantum gravity generically presuppose or predict that the reality underlying relativistic spacetimes they are describing is significantly non-spatiotemporal. On pain of empirical incoherence, approaches to quantum gravity must establish how relativistic spacetime emerges from their non-spatiotemporal structures. We argue that in order to secure this emergence, it is sufficient to establish that only those features of relativistic spacetimes functionally relevant in producing empirical evidence must be recovered. In order to complete this task, an account must be given of (...) how the more fundamental structures instantiate these functional roles. We illustrate the general idea in the context of causal set theory and loop quantum gravity, two prominent approaches to quantum gravity. (shrink)

This paper argues that recent arguments to the effect that the debate between presentism and eternalism lacks any metaphysical substance ultimately fail, although important lessons can be gleaned from them in how to formulate a non-vacuous version of presentism. It suggests that presentism can best be characterized in the context of spacetime theories. The resulting position is an ersatzist version of presentism that admits merely non-present entities as abstracta deprived of physical existence. Ersatzist presentism both escapes the charges of triviality (...) and promises to offer a route to solving the grounding problem which befalls its more traditional cousins. (shrink)

John Scottus Eriugena (d. ca. 877) is regarded as the most important philosopher and theologian in the Latin West from the death of Boethius until the thirteenth century. He incorporated his understanding of Latin sources, Ambrose, Augustine, Boethius and Greek sources, including the Cappadocian Fathers, Pseudo-Dionysius, and Maximus Confessor, into a metaphysics structured on Aristotle's Categories, from which he developed Christian Neoplatonist theology that continues to stimulate 21st-century theologians. This collection of essays provides an overview of the latest scholarship on (...) various aspects of Eriugena's thought and writings, including his Irish background, his use of Greek theologians, his Scripture hermeneutics, his understanding of Aristotelian logic, Christology, and the impact he had on contemporary and later theological traditions. Contributors: David Albertson, Joel Barstad, John Contreni, Christophe Erismann, John Gavin, Adrian Guiu, Michael Harrington, Catherine Kavanagh, A. Kijewska, Stephen Lahey, Elena Lloyd-Sidle, Bernard McGinn, Ernesto Sergio Mainoldi, Dermot Moran, Giulio D'Onofrio, Willemien Otten, and Alfred Siewers. (shrink)

This volume will be an essential resource for anyone working in the central areas of philosophy, and the starting point for future research in this fascinating ...

This volume is a wide-ranging examination of denial and ideological denialism. It offers a readable overview of the psychology and social science of bias, self-deception, and denial, and examines the role of ideological denialism in conflicts over science and public policy, politics, and culture.

Ciencia y lógica de mundos posibles indaga en un aspecto negativo de la visión positivista de la historia del pensamiento. Según esta interpretación, determinante dentro del pensamiento contemporáneo, existe una oposición irredimible entre la metodología del conocimiento científico y la metafísica. El estudio de los supuestos ontológicos de la epistemología aristotélica y de la nueva metodología galileana evidencia, sin embargo, que históricamente la ciencia moderna no nace en oposición a la metafísica, sino que surge a partir de una concepción metafísica (...) determinada. Resulta imposible comprender a fondo el fenómeno de la revolución galileana sin tener en cuenta los aportes lógicos de pensadores medievales que tuvieron una actitud crítica frente a las implicaciones ontológicas de la epistemología aristotélica. Con el advenimiento del idealismo trascendental - a diferencia de Descartes, Leibniz o Newton - la filosofía se separa de la ciencia experimental. Esto se debe a que con Kant la filosofía se aleja de la postura filosófica de los origenes de la ciencia moderna, y retorna a una concepción de la naturaleza en cierto modo similar a la aristotélica. Así mismo, la interpretación propuesta en el manifiesto del Círculo de Viena con respecto a algunas de las revoluciones científicas de los siglos XIX y XX, supone que la ciencia moderna se ha desarrollado en la dirección señalada por la concepción metafísica del mundo que se encuentra en el origen de la revolución galileana. (shrink)