Die Deutsche Forschungsgemeinschaft (DFG) hat ab 2016 eine neue Forschergruppe unter Leitung der Bergischen Universität Wuppertal eingerichtet. Sie untersucht die Forschungen an der „größten Forschungsmaschine der Welt“, dem Large Hadron Collider (LHC) am Europäischen Zentrum für Teilchenphysik CERN in Genf, aus philosophischer, historischer und soziologischer Sicht. Wissenschaftsphilosophisch sind diese Forschungen vor allem aus drei Gründen relevant: Die Philosophie interessiert sich für den Ursprung und die grundlegenden Strukturen der Welt, für die Bedingungen des Erkenntniserfolges der Elementarteilchenphysik und nicht zuletzt für die (...) mit den Erfolgen mitunter eng verbundenen theoretischen und praktischen Probleme. Die Diskussion dieser Gründe zeigt die Elementarteilchenphysik als eine lebensweltferne, zugleich aber weltbildrelevante, theoretisch wie praktisch äußerst erfolgreiche Disziplin, die dennoch nicht frei von gewichtigen offenen Fragen ist. Sie könnte ein Typus für die Gewinnung von Wissen an den Grenzen unserer Erkenntnis sein. (shrink)

In this paper a few facts about Feynman diagrams and the perturbation expansion of the S-matrix are reviewed and discussed in connection with the question of the ontological status of virtual particles.

A virtual particle is an elementary particle in a quantum field theory that serves to symbolise the interaction of its counterparts, the so called real particles. In the last 20 years, philosophers of physics have put forth several arguments for and against an interpretation of virtual particles as being like ordinary objects in space and time. In this article, I will attempt to systematise the major arguments and argue that no pro-argument is ultimately satisfactory, and that (...) only one contra-argument—that of superposition—is sufficient to deny the realistic interpretation of virtual particles. The secondary aim of this paper is to argue that even the philosophical considerations of virtual particles overestimate their role in that these entities are merely pictorial descriptions of a mathematical approximation method. This description, while helpful, is not necessary to understand particle interactions. In the end, quantum field theory is not the place to explain what actually happens in the very centre of an individual particle interaction. (shrink)

First the “frame problem” is sketched: The motion of an isolated particle obeys a simple law in Galilean frames, but how does the Galilean character of the frame manifest itself at the place of the particle? A description of vacuum as a system of virtual particles will help to answer this question. For future application to such a description, the notion of global particle is defined and studied. To this end, a systematic use of the Fourier (...) transformation on the Poincaré group is needed. The state of a system of n free particles is represented by a statistical operator W, which defines an operator-valued measure on ^Pn (^P is the dual of the Poincaré group). The inverse Fourier–Stieltjes transform of that measure is called the characteristic function of the system; it is a function on Pn. The main notion is that of global characteristic function: it is the restriction of the characteristic function to the diagonal subgroup of Pn; it represents the state of the system, considered as a single particle. The main properties of characteristic functions, and particularly of global characteristic functions, are studied. A mathematical Appendix defines two functional spaces involved. (shrink)

Examining the process of action at a distance, we arrive at the following conclusions: (a) The virtual photons and mesons transmitting Coulomb and nuclear forces, respectively, do not arise from “temporary violations of energy conservation,” but, on the contrary, exactly embody the potential energy corresponding to the relevant forceF that they transmit on their collision with the charged particles or nucleons via the formula Δp=FΔt. (b) In the case of an attractive force, the energy of these photons and mesons (...) is negative. The way this comes about is made clear by a more detailed investigation of Feynman's notion of “traveling backward in time.” (c) The action corresponding to, e.g., a virtual photon's appearance is exactly one quantumh, which fact is responsible for the unobservability of such photons. Some consequences of the revised conception of potential energy for, e.g., the tunnel and the Bohm-Aharonov effect are mentioned. (shrink)

The question of the relation between the amplitude of the photon vector potential and its angular frequency is analyzed. The analogy between the relativistic quantum mechanical equations for a massles particle and those governing the photon vector potential appears clearly. Finally, the virtual electromagnetic waves associated with the photon and predicted by de Broglie, Bohr, and other appear naturally as a result of the photon vector potential quantification.

Cet article examine certains aspects sociocognitifs et sémiotiques des jeux virtuels. Il commence par rappeler quelques travaux sociocognitifs fondamentaux relatifs au cheminement du joueur dans un espace virtuel et présente des acquis récents à la lumière de travaux en neurosciences. Ces acquis concernent le codage commun des fonctions relatives à l’espace, notamment la perception d’un espace virtuel ainsi que du mouvement et de la rotation dans celui-ci. Un résultat important est que ces jeux virtuels améliorent les performances du joueur. La (...) contribution aborde ensuite le contrôle sémiotique du processus et insiste sur l’instrumentalisation de la fonction abductive comme balisage de la construction du sens du jeu par le joueur. Elle se termine par un retour sur le jeu virtuel en tant que dispositif sociocognitif et sémiotique de communication et sur sa nécessaire prise en compte lors de la phase de conception.This contribution explores some of the sociocognitive and semiotic aspects of virtual games. We begin by reviewing a number of fundamental studies on the way players move through virtual space, describing recent findings in the light of neuroscientific research. These concern the common mental coding of functions relating to space, and especially perceptions of virtual space and mental motion and rotation within it. One important finding is that these virtual games improve the performance of players. We then look into semiotic control of the game, highlighting the instrumentalisation of the abductive function to provide reference points in the construction of meaning by the game player. We conclude with a discussion on virtual games as a socio- cognitive and semiotic means of communication and on the need to take this into account in the early stages of game design. (shrink)

A macroscopic realization of the peculiar virtual particles is presented. The classical Helmholtz and the Schrödinger equations are differential equations of the same mathematical structure. The solutions with an imaginary wave number are called evanescent modes in the case of elastic and electromagnetic fields. In the case of non-relativistic quantum mechanical fields they are called tunneling solutions. The imaginary wave numbers point to strange consequences: The waves are non-local, they are not observable, and they are described as virtual (...) particles. During the last two decades QED calculations of the solutions with an imaginary wave number have been experimentally confirmed for phonons, photons, and electrons. The experimental proofs of the predictions of non-relativistic quantum mechanics and the Wigner phase time approach for the elastic, electromagnetic and Schrödinger fields will be presented in this article. The results are zero time in the barrier and an interaction time (i.e. a phase shift) at the barrier interfaces. The measured tunneling time scales approximately inversely with the particle energy. Actually, the tunneling time is given only by the barrier boundary interaction time, as zero time is spent inside a barrier. (shrink)

David Chalmers a récemment soutenu que la réalité virtuelle est réelle, plutôt que fictionnelle. Dans cet article, j’examine les implications ontologiques de ce « réalisme virtuel ». Comme je le suggère, cette position s’associe naturellement à une ontologie algorithmique, qui identifie les objets virtuels à des structures de données comprises de manière fonctionnelle. Je présente ensuite plusieurs objections à cette ontologie algorithmique. Tant que celles-ci ne sont pas réglées, la question de l’identité des mondes et des objets virtuels reste (...) encore en suspens. (shrink)

This article presents a phenomenological perspective on the “virtual organisation” where people are obliged to work at a distance and where contact with others is limited to that of an electronic network. Drawing on Husserl, we see that when the “as-if ” presence is contrived in such a way, the organisation obstructs the life of consciousness. Furthermore, relying on Michel Henry’s writings, we explain how removing the parameter of “flesh” as a factor structuring encounters, this organizational form profoundly restricts (...) the dynamism of the acting, subjective life. (shrink)

Paper on the metaphysics of virtual worlds, the problem of other minds, and the origins of ethical behavior.

This paper aims to determine the ontology of virtual reality from a historical and systematic point of view. The term “virtual reality” is often used synonymously with “illusion”, “immersion”, “simulation” or “fiction”. Against this anti-realistic view, the paper argues that virtual reality is a genuine kind of reality that has always been part of our life. To this end, I will analyze the ontology of virtual reality by using the example of banknotes and referring to Lynne (...) Baker’s “constitution view”. Finally, I shall attempt to define the term “virtual reality” from a philosophical point of view by distinguishing it from the concepts of simulation and illusion. (shrink)

It is with good reason that the name Rutherford is closely linked with the early history of the alpha particle. He discovered them, determined their nature, and from 1909 used them to probe the structure of the atom. From 1898 to 1902 Rutherford construed alpha radiation as a type of non-particulate Röntgen radiation. On his theory of the locomotion of radioactive particles Rutherford proposed that alpha radiation consisted of negatively charged particles. During 1902 he confirmed the particulate nature of (...) alpha radiation but discovered that these alpha particles were positively charged. Although Rutherford suspected from 1903 that these alpha particles were related somehow with helium, the proof required six long years of investigation. By mid-1908 it seemed certain that the alpha particle possessed two units of the elementary charge. Since the e/m ratio had already been determined for alpha particles, this evidence enhanced the suspected connection with helium. However, this gain and loss of charge was still construed as an ionization effect. Since as late as 1908 gaseous ionization was assumed to involve the gain or loss of a single unit of charge, Rutherford's alleged case of doubly ionized alpha particles was presumably an exception. Yet helium was known to be an inert gas and thus hardly a likely candidate for such exceptional ionization behaviour. To establish the connection, therefore, Rutherford resorted to a spectroscopic test. He collected spent alpha particles shot into a thin glass tube and gradually observed the spectrum of helium. Rutherford had thus been correct in his assumption, but a proper explanation was possible only after the confirmation of the nuclear structure of the atom. (shrink)

Il s’agit ici d’analyser un objet urbain, la caméra de vidéosurveillance, et de saisir de quelle manière cet objet segmente virtuellement – mais effectivement – l’espace urbain et affecte intimement les individus. Dans un contexte de brouillage entre sphère publique et privée, nous montrerons comment les dispositifs de caméras, tout en participant à la dislocation de la masse, peuvent être considérés comme les nouveaux murs de nos individuations.This article analyses an urban object, the video surveillance camera, and attempts to show (...) how it segments city spaces – virtually but effectively – and closely affects individuals. In a context of blurred boundaries between the public and private spheres, we show how video camera systems, while contributing to the dislocation of urban masses, can also be seen as a new way of ring-fencing human individuation. (shrink)

This article discusses the meaning of the notion of virtuality in modern physics. To this end, it develops considerations on the introduction and establishment in nuclear physics of two independent concepts at the turn of the 1920s and 1930s: that of the virtual state, used in the context of neutron scattering studies, and that of the virtual transition, useful for the theoretical understanding of strong nuclear forces, which forms the basis of what are now called virtual particles. (...) Their comparative analysis highlights the theoretical nature of virtual entities and processes in modern physics. It also shows how the virtual has been associated with various purely physical attributes, leading to a form of polysemy of the term, from the beginning of the application of these concepts. (shrink)

Les mondes virtuels sont issus des MMORPG, Massively Multiplayer Online Role-Playing Games qui sont eux-mêmes issus du monde du jeu vidéo. À ce titre, il existe une filiation « ludique » entre ces différents dispositifs. Les travaux de Steinkuehler suggèrent que les mécanismes de l’apprentissage générés par les jeux issus des mondes virtuels dépendent « certes de la nature du jeu mais aussi des pratiques sociales qu’ils engendrent ». Dans cette continuité, nous avons démontré dans nos travaux que ces environnements (...) immersifs permettaient de créer du lien social et donnaient lieu à des formes de rites numériques entre sphère privée et publique. Dans cet article nous nous intéressons aux controverses des environnements immer- sifs en questionnant la place du corps virtuel au sein de ces dispositifs qui pourraient se situer selon nous, entre lieux de spectacle, de loisir et d’apprentissage médiatisé. Le cas des serious games sera évoqué à titre d’illustration.Virtual worlds started with the MMORPG who emerged from the video gaming world, thus indicating their play-related origins. Steinkuehler’s work suggests that the learning mechanisms triggered by games in the virtual world depend “on the nature of the game obviously, but also on the social practices they give rise to”. Continuing this line of study, our work shows that these immersive environments actually forge social ties and generate digital rites of various kinds between the public and private spheres. In this article, we explore the controversies around immersive environments through an investigation of the virtual body within these systems, which we believe function as venues partly for entertainment, partly for leisure and partly as mediated learning spaces. The case of “serious games” is discussed here as an illustration. (shrink)

Fictif, artificiel, imaginaire, trompeur, immatériel, irréel, impalpable, invisible, mystérieux... Lorsque l'on pense au virtuel, une foule d'idées nous submerge. Concept aux valeurs sémantiques multiformes et aux différents usages, sa signification reste floue et son sens en perpétuel mouvement. Qu'est-ce " réellement " que le virtuel? Quel rapport entre le sens philosophique et son emploi dans le domaine du numérique? Quelles sont ses implications politiques? Quelle conception de la réalité en découle?Ce livre se veut une cartographie offrant des repères stables pour (...) s'orienter et naviguer à travers le concept de virtuel. L'effet d'un phare en plein brouillard... Ainsi, le présent ouvrage expose et analyse plusieurs aspects de la cryptographie et leurs interactions avec les avancées théoriques et pratiques de plusieurs disciplines scientifiques et techniques. (shrink)

Les technologies de l'information et le e-learning sont souvent invoqués par les grands organismes internationaux de coopération comme l'unique moyen de sauver de ses faiblesses l'enseignement supérieur en Afrique. Le renforcement des universités traditionnelles, la modernisation de leurs laboratoires, les dotations en faveur de leurs bibliothèques ne semblent jamais être proposés comme solution. Ce positivisme technologique trouve l'une de ses principales manifestations dans le lancement par la Banque mondiale, en 1997, de l'Université virtuelle africaine . Près de dix ans (...) après sa création, elle se situe encore au coeur des stratégies des institutions financières internationales concernant l'enseignement à distance en Afrique. Etudier l'UVA conduit à s'interroger sur les objectifs éducatifs et politiques de ses commanditaires. Contribue-t-elle à améliorer la situation des établissements d'enseignement supérieur africains?The information technology and e-learning are often used by major international cooperation as the only way to save weaknesses of higher education in Africa. Strengthening of traditional universities to modernize their laboratories, allocations for their libraries never seem to be offered as a solution. This technology is positivism one of its main events in the launch of the World Bank, in 1997, the African Virtual University . Nearly ten years after its creation, it is still at the heart of the strategies of international financial institutions for distance education in Africa. UVA Study raises questions about educational goals and policies of its sponsors. She contributes to improving the situation of African higher education institutions? (shrink)

Las comunidades en línea han sido vistas como una nueva esfera social que coadyuva al surgimiento de procesos democráticos de forma más rápida y óptima, de lo que sucede en las relaciones del mundo físico. Sin embargo, los alcances y características de estas interacciones sociales aún están por verse. El propósito de este documento es discutir hasta qué punto la acción de los individuos en estas comunidades difiere del funcionamiento tradicional de cualquier comunidad ¿Hasta dónde los espacios virtuales cumplen con (...) las aspiraciones y promesas con las que han sido investidos? Un primer punto versará sobre las complejidades del establecimiento de comunidades en línea, para después pasar a determinar la forma en que se establecen las normas en estos espacios. Por último el trabajo se enfocará al estudio de caso de una comunidad virtual argentina denominada Taringa! (shrink)

The significance of the de Broglie/Bohm hidden-particle position in the relativistic regime is addressed, seeking connection to the single-particle Newton–Wigner position. The effect of non-positive excursions of the ensemble density for extreme cases of positive-energy waves is easily computed using an integral of the equations of motion developed here for free spin-0 particles in 1 + 1 dimensions and is interpreted in terms of virtual-like pair creation and annihilation beneath the Compton wavelength. A Bohm-theoretic description of the (...) acausal explosion of a specific Newton–Wigner-localized state is presented in detail. The presence of virtual pairs found is interpreted as the Bohm picture of the spatial extension beyond single point particles proposed in the 1960s as to why space-like hyperplane dependence of the Newton–Wigner wavefunctions may be needed to achieve Lorentz covariance. For spin-1/2 particles the convective current is speculatively utilized for achieving parity with the spin-0 theory. The spin-0 improper quantum potential is generalized to an improper stress tensor for spin-1/2 particles. (shrink)

Sorti exsangue de la Seconde Guerre mondiale, le Japon s'est superbement redressé grâce à ses innovations techniques, d'abord destinées à améliorer le quotidien du peuple. Aujourd'hui, face à de nouveaux maux sociaux, dont l'inéluctable vieillissement rapide de la population et l'anxiété croissante face à un monde chamboulé, le recours à des solutions scientifiques et techniques est, pour les Japonais, une évidence. À tort ou à raison, les machines ne leur font pas peur. Mieux, elles les émerveillent. Et lorsque les Japonais (...) usent de moyens de télécommunications toujours plus puissants et omniprésents, ou fréquentent des mondes irréels, n'est-ce pas un moyen d'éviter la confrontation directe avec autrui ou soi-même, en choisissant la représentation virtuelle de l'être idolâtré ou en se recréant sous une forme idéalisée ?Out bloodless WWII, Japan has recovered superbly thanks to its technical innovations, all aimed at improving the lives of the people. Today, faced with new social ills, including the inevitable rapid aging of the population and the growing anxiety in a world turned upside down, the use of scientific and technical solutions is for the Japanese evidence. Wrongly or rightly, the machines do not scare them. Best, they all marveled. And when the Japanese wear of telecommunications increasingly powerful and ubiquitous, or attend unreal worlds, is not this a way to avoid direct confrontation with others or yourself, choosing the virtual representation of the be idolized or by recreating an idealized form? (shrink)

Variable particle masses have sometimes been invoked to explain observed anomalies in low energy nuclear reactions (LENR). Such behavior has never been observed directly, and is not considered possible in theoretical nuclear physics. Nevertheless, there are covariant off-mass-shell theories of relativistic particle dynamics, based on works by Fock, Stueckelberg, Feynman, Greenberger, Horwitz, and others. We review some of these and we also consider virtual particles that arise in conventional Feynman diagrams in relativistic field theories. Effective Lagrangian models (...) incorporating variable mass particle theories might be useful in describing anomalous nuclear reactions by combining mass shifts together with resonant tunneling and other effects. A detailed model for resonant fusion in a deuterium molecule with off-shell deuterons and electrons is presented as an example. Experimental means of observing such off-shell behavior directly, if it exists, is proposed and described. Brief explanations for elemental transmutation and formation of micro-craters are also given, and an alternative mechanism for the mass shift in the Widom–Larsen theory is presented. If variable mass theories were to find experimental support from LENR, then they would undoubtedly have important implications for the foundations of quantum mechanics, and practical applications may arise. (shrink)

Considering the highly complex structure of quantum chaos and the nonstationary characteristics of speech signals, this paper proposes a quantum chaotic encryption and quantum particle swarm extraction method based on an underdetermined model. The proposed method first uses quantum chaos to encrypt the speech signal and then uses the local mean decomposition method to construct a virtual receiving array and convert the underdetermined model to a positive definite model. Finally, the signal is extracted using the Levi flight strategy (...) based on kurtosis and the quantum particle swarm optimization optimized by the greedy algorithm. The bit error rate and similarity coefficient of the voice signal are extracted by testing the source voice signal SA1, SA2, and SI943 under different SNR, and the similarity coefficient, uncertainty, and disorder of the observed signal and the source voice signal SA1, SA2, and SI943 verify the effectiveness of the proposed speech signal extraction method and the security of quantum chaos used in speech signal encryption. (shrink)

In this contribution in honour of Paul Busch, we criticise the claims of many expositions that the time-energy uncertainty principle allows both a violation of energy conservation and particle creation, provided that this happens for a sufficiently short time. But we agree that there are grains of truth in these claims: which we make precise and justify using perturbation theory.

El artículo ofrece un análisis crítico del impacto contemporáneo que está teniendo la proliferación de una Educación Ambiental (EA) de nueva generación apoyada por herramientas tecnológicas virtuales en la construcción de una renovada identidad profesional, de un sujeto ecológico postmoderno en continua reconstrucción, reciclado por la influencia que ejerce la tecnología en su práctica laboral ordinaria y en su vida cotidiana como ciudadano ambientalmente comprometido. A los treinta años de Tbilisi se reconstruyen algunos patrones de cambio significativo valorando las limitaciones (...) y oportunidades de los nuevos modelos. Desde los presupuestos de la investigación fenomenológica nos acercamos a los diferentes rasgos del nuevo sujeto ecológico de nuestro tiempo, donde un nuevo concepto de educador ambiental y de EA se perfila empujado por los avances tecnológicos al albur de realidades virtuales, redes sociales y medios de comunicación. (shrink)

Le campus virtuel de la filière TIC de Limoges propose depuis 1998, via Internet, des formations diplômantes pour les TIC et par les TIC. Les 600 étudiants sont organisés en communautés virtuelles d'apprentissage. Les communautés virtuelles sont une forme de socialisation propre à Internet. Le travail de groupe évite le sentiment d'isolement et facilite les apprentissages. Les étudiants et les enseignants échangent et partagent au niveau de la communauté globale, au niveau des communautés de promotion et d'unité d'enseignement qui sont (...) des communautés de pratique. Ils pratiquent le travail collaboratif au niveau des communautés de travail, c'est-à-dire qu'ils mutualisent leurs compétences et coordonnent leurs actions pour mener à bien les apprentissages. Pour réussir ce travail collaboratif il ya des règles et une « nétiquette » à respecter. L'intelligence collective naît du travail en commun des étudiants en réseau.The virtual campus of the ICT sector offers Limoges since 1998, via the Internet, diploma courses for ICT and ICT. 600 students are organized in virtual learning communities. Virtual communities are a form of socialization own Internet. Group work prevents isolation and facilitates learning. Students and teachers exchange and share in the global community, community-level promotion and teaching unit which are communities of practice. They practice in collaborative working communities, that is to say, they pool their expertise and coordinate their actions to carry out learning. To achieve this collaboration there are rules and "netiquette" to follow. Collective intelligence born of students working together in a network. (shrink)

In the standard formalism of quantum gravity, black holes appear to form statistical distributions of quantum states. Now, however, we can present a theory that yields pure quantum states. It shows how particles entering a black hole can generate firewalls, which however can be removed, replacing them by the ‘footprints’ they produce in the out-going particles. This procedure can preserve the quantum information stored inside and around the black hole. We then focus on a subtle but unavoidable modification of the (...) topology of the Schwarzschild metric: antipodal identification of points on the horizon. If it is true that vacuum fluctuations include virtual black holes, then the structure of space-time is radically different from what is usually thought. (shrink)

The digitally generated worlds of the virtual are not antagonistic to the usual reality, but increasingly develop into homologous alternatives within ordinary reality. The use of technopractices such as virtual reality and communication with algorithm-based virtual entities, which are more and more turning into a (proto-)social element of our society, not only makes the contingency of our world apparent, but also allows us to observe the reflexivity of our own observation of this contingency. Hence, acting and experiencing (...) in virtual worlds and with virtual communication partners does not necessarily imply a loss of reality, but on the contrary, it may bring us multifarious enrichments of reality. However, the cultural process of digitalization also brings in its wake a new narcissistic insult to mankind: Reflected by self-learning machines that reproduce human intelligence to an unimagined degree, we painfully learn that the human self is always merely socially formatted and can operate only within the confnes, and by the standards, of habituation and socialization. (shrink)

We describe vacuum as a system of virtual particles, some of which have negative energies. Any system of vacuum particles is a part of a keneme, i.e., of a system of n particles which can, without violating the conservation laws, annihilate in the strict sense of the word (transform into nothing). A keneme is a homogeneous system, i.e., its state is invariant by all transformations of the invariance group. But a homogeneous system is not necessarily a keneme. In the (...) simple case of a spin system, where the invariance group is SU(2), a homogeneous system is a system whose total spin is unpolarized; a keneme is a system whose total spin is zero. The state of a homogeneous system is described by a statistical operator with infinite trace (von Neumann), to which corresponds a characteristic distribution. The characteristic distributions of the homogeneous systems of vacuum are defined and studied. Finally it is shown how this description of vacuum can be used to solve the frame problem posed in paper (I). (shrink)

Résumé David Chalmers maintient que la réalité virtuelle est une véritable réalité. Une version de ce « réalisme virtuel » affirme que les entités virtuelles dépendent ontologiquement d'entités numériques réelles. Nous explorons ici cette suggestion, en proposant un nouveau modèle pour décrire la dépendance du virtuel à l’égard du numérique. En nous appuyant sur la théorie de la constitution de Lynne Rudder Baker, nous défendons que les objets virtuels sont constitués par des objets numériques, lorsque ceux-ci se trouvent dans (...) certaines circonstances favorables. Nous explorons les motivations et les implications de cette approche, que nous considérons comme une forme prometteuse de réalisme virtuel. (shrink)

Dans La structure du comportement Merleau-Ponty introduit le concept d' « espace virtuel », dans la Phénoménologie de la perception ceux de « mouvement virtuel » et de « corps virtuel ». L'objectif de cet article est d'établir les liens entre ces trois notions que Merleau-Ponty emprunte à la littérature psychologique de son temps et de montrer pourquoi elles constituent des éléments-clés de sa philosophie de la perception.

This paper will not present a case study of the historical development of a virtual entity. Rather, I will develop an outlook on virtual entities in the sciences and propose a corresponding method for studying them (historically). In essence, my presentation can be considered a synthesis of different observations from the history and philosophy of science and has its roots in my dissertational research on the development of the virtual particle. Starting with a reflection on the (...) role of presentism for the study of concept formation and development processes, I will show, through the example of the virtual particle, how current debates and interpretations can inform our access to a historical reconstruction. Following these reflections, I will argue for a pragmatist account of concepts as tools for the scientific practitioners. According to the approach presented in my article, concepts perform their functions through representations, and I will lay special focus on verbal representations and their different functions within scientific reasoning. In conclusion, I will frame the outcome of my discussion in terms of a proposal that might, through further research, enrich our understanding of virtual entities in the sciences. (shrink)

Proceedings of SPIE present the original research papers presented at SPIE conferences and other high-quality conferences in the broad-ranging fields of optics and photonics. These books provide prompt access to the latest innovations in research and technology in their respective fields. Proceedings of SPIE are among the most cited references in patent literature.

L'article se propose d'étudier le rôle important que Bergson fait jouer à la notion de « virtuel » dans la théorie de la « perception pure » exposée dans le premier chapitre de Matière et mémoire. Cette théorie fait en effet intervenir successivement les concepts de « perception virtuelle », d'« action virtuelle », d' « image virtuelle ». Malgré les similarités qui apparaissent entre les mécanismes de la perception et de la mémoire qui s'ordonnent toutes deux (...) autour de la sélection, décrite comme une actualisation, d'éléments préalablement donnés (images ou souvenirs), la fonction du virtuel apparaît différente ; il faut donc conclure qu'il ne constitue pas un concept unifié et cohérent, d'autant plus que Bergson emploie également ce terme pour caractériser des systèmes philosophiques ou scientifiques dont il cherche à se démarquer. (shrink)

An analysis of the physical implications of abstractness reveals the reality of three interconnected modes of existence: abstract, virtual and concrete, corresponding in physics to information, energy and matter. This triple-aspect monism clarifies the ontological status of subatomic quantum particles. It also provides a non-spooky solution to the weirdness of quantum physics and a new outlook for the mind-body problem. The ontological implications are profound for both physics and philosophy.

The success of particle detection in high energy physics colliders critically depends on the criteria for selecting a small number of interactions from an overwhelming number that occur in the detector. It also depends on the selection of the exact data to be analyzed and the techniques of analysis. The introduction of automation into the detection process has traded the direct involvement of the physicist at each stage of selection and analysis for the efficient handling of vast amounts of (...) data. This tradeoff, in combination with the organizational changes in laboratories of increasing size and complexity, has resulted in automated and semi-automated systems of detection. Various aspects of the semi-automated regime were greatly diminished in more generic automated systems, but turned out to be essential to a number of surprising discoveries of anomalous processes that led to theoretical breakthroughs, notably the establishment of the Standard Model of particle physics. The automated systems are much more efficient in confirming specific hypothesis in narrow energy domains than in performing broad exploratory searches. Thus, in the main, detection processes relying excessively on automation are more likely to miss potential anomalies and impede potential theoretical advances. I suggest that putting substantially more effort into the study of electron–positron colliders and increasing its funding could minimize the likelihood of missing potential anomalies, because detection in such an environment can be handled by the semi-automated regime—unlike detection in hadron colliders. Despite virtually unavoidable excessive reliance on automated detection in hadron colliders, their development has been deemed a priority because they can operate at currently highest energy levels. I suggest, however, that a focus on collisions at the highest achievable energy levels diverts funds from searches for potential anomalies overlooked due to tradeoffs at the previous energy thresholds. I also note that even in the same collision environment, different research strategies will opt for different tradeoffs and thus achieve different experimental outcomes. Finally, I briefly discuss current searches for anomalous process in the context of the previous analysis. (shrink)

En 1819, Maine de Biran rédige une Exposition du système de Leibniz. Ce texte accorde une place centrale à la virtualité en l'associant à trois éléments-clés du système leibnizien : la monade miroir représentant « virtuellement » l'univers ; la conception dynamique de la substance constituée par une tendance virtuelle ; l'innéité des idées qui résulterait, aux yeux de Biran, d'une application de la dynamique et plus précisément du concept de la « force considérée comme virtuelle ». Ces (...) trois références à la virtualité comportent donc un aspect problématique que l'article tente d'éclairer en s'appuyant sur le rôle que Maine de Biran lui-même fait jouer à la virtualité dans son propre itinéraire philosophique. En particulier, le Mémoire sur la décomposition de la pensée fait jouer un rôle central à la « force virtuelle » (virtual force) en tant que force préexistant au moi, et permettant d'échapper au substantialisme. La force virtuelle apparaît comme un concept malléable permettant de concilier deux concepts initialement antinomiques pour Biran, celui de substance et celui d'activité. Or c'est précisément aussi ce que fait la dynamique leibnizienne à ses yeux. La tentation est dès lors très forte d'attribuer ce concept-clé à Leibniz lui-même, d'autant plus que Jean Bernoulli, Emilie du Chatelet, D'Alembert, avaient déjà introduit la virtualité dans le lexique de la dynamique leibnizienne pour qualifier la force morte (dead force). Biran est ainsi conduit à reconstituer l'itinéraire intellectuel de Leibniz et à considérer que ce dernier a puisé son concept de force dans l'expérience de l'aperception (apperception), au sens biranien du terme. (shrink)

Contrary to his original plans, Alexander Pfänder's "Zur Psychologie der Gesinnungen, I. und II. Teil" has remained a fragment, and does not include, the chapter on the virtual sentiments with an addition referring to the virtual psyche in general. Sixty-seven pages of Pfänder's posthumous writings, located at the Bavarian State Library in Munich, deal with the virtual psyche in general and the virtual sentiments in specific. These manuscripts contain the only passages where Pfänder is concerned with (...) the virtual psyche in detail and are preliminary studies for the above-mentioned chapter. (shrink)

Two luminaries of 20th century astrophysics were Sir James Jeans and Sir Arthur Eddington. Both took seriously the view that there is more to reality than the physical universe and more to consciousness than simply brain activity. In his Science and the Unseen World Eddington speculated about a spiritual world and that "conscious is not wholly, nor even primarily a device for receiving sense impressions." Jeans also speculated on the existence of a universal mind and a non-mechanical reality, writing in (...) his The Mysterious Universe "the universe begins to look more like a great thought than like a great machine." In his book QED Feynman discusses the situation of photons being partially transmitted and partially reflected by a sheet of glass: reflection amounting to four percent. In other words one out of every 25 photons will be reflected on average, and this holds true even for a "one at a time" flux. The four percent cannot be explained by statistical differences of the photons nor by random variations in the glass. Something is "telling" every 25th photon on average that it should be reflected back instead of being transmitted. Other quantum experiments lead to similar paradoxes. To explain how a single photon in the two-slit experiment can "know" whether there is one slit or two, Hawking and Mlodonow write: In the double-slit experiment Feynman's ideas mean the particles take paths that thread through the first slit, back out though the second slit, and then through the first again; paths that visit the restaurant that serves that great curried shrimp, and then circle Jupiter a few times before heading home; even paths that go across the universe and back. This, in Feynman's view, explains how the particle acquires the information about which slits are openŠ. It is hard to imagine a more absurd physical explanation. We can think of no way to hardwire the behavior of photons in the glass reflection or the two-slit experiments into a physical law. On the other hand, writing a software algorithm that would yield the desired result is really simple. A digital reality whose laws are software is an idea that has started to gain traction in large part thanks to an influential paper in Philosophical Quarterly by Oxford professor Nick Bostrom. Writing in the New York Times John Tierney had this to say: Until I talked to Nick Bostrom, a philosopher at Oxford University it never occurred to me that our universe might be somebody else's hobby. But now it seems quite possible. In fact, if you accept a pretty reasonable assumption of Dr. Bostrom's, it is almost a mathematical certainty that we are living in someone else's computer simulation. An alternate view is that there exists a great consciousness whose mind is the hardware, and whose thoughts are the software creating a virtual universe in which we as beings of consciousness live. 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)

In this article, we demonstrate a sense in which the one-particle quantum mechanics and the classical electromagnetic four-potential arise from the quantum field theory. In addition, the classical Maxwell equations are derived from the QFT scattering process, while both classical electromagnetic fields and potentials serve as mathematical tools to approximate the interactions among elementary particles described by QFT physics. Furthermore, a plausible interpretation of the Aharonov–Bohm effect is raised within the QFT framework. We provide a quantum treatment of the (...) source of electromagnetic potentials and argue that the underlying mechanism in the AB effect can be understood via interactions among electrons described by QFT theory where the interactions are mediated by virtual photons. (shrink)

Graham Harman’s Object-Oriented Ontology has employed a variant of occasionalist causation since 2002, with sensual objects acting as the mediators of causation between real objects. While the mechanism for living beings creating sensual objects is clear, how nonliving objects generate sensual objects is not. This essay sets out an interpretation of occasionalism where the mediating agency of nonliving contact is the virtual particles of nominally empty space. Since living, conscious, real objects need to hold sensual objects as sub-components, but (...) nonliving objects do not, this leads to an explanation of why consciousness, in Object-Oriented Ontology, might be described as doubly withdrawn: a sensual sub-component of a withdrawn real object. (shrink)

Physical vacuum is a special superfluid medium. Its motion is described by the Navier–Stokes equation having two slightly modified terms that relate to internal forces. They are the pressure gradient and the dissipation force because of viscosity. The modifications are as follows: the pressure gradient contains an added term describing the pressure multiplied by the entropy gradient; time-averaged viscosity is zero, but its variance is not zero. Owing to these modifications, the Navier–Stokes equation can be reduced to the Schrödinger equation (...) describing behavior of a particle into the vacuum, which looks like a superfluid medium populated by enormous amount of virtual particle–antiparticle pairs. (shrink)

This article explores the relationships between the philosophical foundations of quantum field theory, the currently dominant form of quantum physics, and Deleuze's concept of the virtual, most especially in relation to the idea of chaos found in Deleuze and Guattari's What is Philosophy?. Deleuze and Guattari appear to derive this idea partly from the philosophical conceptuality of quantum field theory, in particular the concept of virtual particle formation. The article then goes on to discuss, from this perspective, (...) the relationships between philosophy and science, and between their respective ways of confronting chaos, a great enemy but also a great friend of thought, and its greatest ally in its struggle against opinion. (shrink)