Relational Spacetime Ontology

In the aftermath of the rediscovery of Einstein’s hole argument by Earman and Norton (1987), we hear that the ontological relational/substantival debate over the status of spacetime seems to have reached stable grounds. Despite Einstein’s early intention to cast GR’s spacetime as a relational entity à la Leibniz-Mach, most philosophers of science feel comfortable with the now standard sophisticated substantivalist (SS) account of spacetime. Furthermore, most philosophers share the impression that although relational accounts of certain highly restricted models of GR are viable, at a deep down level, they require substantival spacetime structures. SS claims that although manifold spacetime points do not enjoy the sort of robust existence provided by primitive identity, it is still natural to be realistic about the existence of spacetime as an independent entity in its own right. It is argued that since the bare manifold lacks the basic spacetime structures –such as geometry and inertia- one should count as an independent spacetime the couple manifold +metric (M, g). The metric tensor field of GR encodes inertial and metrical structure so, in a way, it plays the explanatory role that Newtonian absolute space played in classical dynamics. In a nutshell, according to the SS account of spacetime, one should view the metric field of GR as the modern version of a realistically constructed spacetime since it has the properties –or contains the structures- that Newtonian space had. I will try to dismantle the widespread impression that a relational account of full GR is implausible. To do so, I will start by highlighting that when turning back to the original Leibniz-Newton dispute one sees that substantivalism turns out prima facie triumphant since Newton was able to successfully formulate dynamics. However, to give relationalism a fair chance, one can also put forward the following hypothetical questions: What if Leibniz –or some leibnizian- had had a good relational theory? What role would geometry play in this type of theory? Would it be natural to view geometry and inertia as intrinsic properties of substantival space –if not spacetime? Would it still seem natural to interpret the metric field of GR along substantival lines regardless of the fact that it also encodes important material properties such as energy-momentum? After bringing these questions out into the light I will cast some important doubts on the substantival (SS) interpretation of the metric field. Perhaps the metric turns out to be viewed as a relational matter field. Finally, to strengthen the relational account of spacetime I expect to remove the possible remaining interpretative tension by briefly discussing the relevance of two important facts: i) Dynamical variables are usually linked to material objects in physical theories. The metric field of GR is a dynamical object so, I claim, it should be viewed as a matter field. ii) Barbour and Bertotti (BB2, 1982) have provided and alternative formulation of classical dynamics. They provide a “genuinely relational interpretation of dynamics” (Pooley & Brown 2001). Geometry and inertia become –contra SS- relational structures in BB2

Relational Spacetime Ontology

In the aftermath of the rediscovery of Einstein’s hole argument by Earman and Norton (1987), we hear that the ontological relational/substantival debate over the status of spacetime seems to have reached stable grounds. Despite Einstein’s early intention to cast GR’s spacetime as a relational entity à la Leibniz-Mach, most philosophers of science feel comfortable with the now standard sophisticated substantivalist (SS) account of spacetime. Furthermore, most philosophers share the impression that although relational accounts of certain highly restricted models of GR are viable, at a deep down level, they require substantival spacetime structures. SS claims that although manifold spacetime points do not enjoy the sort of robust existence provided by primitive identity, it is still natural to be realistic about the existence of spacetime as an independent entity in its own right. It is argued that since the bare manifold lacks the basic spacetime structures –such as geometry and inertia- one should count as an independent spacetime the couple manifold +metric (M, g). The metric tensor field of GR encodes inertial and metrical structure so, in a way, it plays the explanatory role that Newtonian absolute space played in classical dynamics. In a nutshell, according to the SS account of spacetime, one should view the metric field of GR as the modern version of a realistically constructed spacetime since it has the properties –or contains the structures- that Newtonian space had. I will try to dismantle the widespread impression that a relational account of full GR is implausible. To do so, I will start by highlighting that when turning back to the original Leibniz-Newton dispute one sees that substantivalism turns out prima facie triumphant since Newton was able to successfully formulate dynamics. However, to give relationalism a fair chance, one can also put forward the following hypothetical questions: What if Leibniz –or some leibnizian- had had a good relational theory? What role would geometry play in this type of theory? Would it be natural to view geometry and inertia as intrinsic properties of substantival space –if not spacetime? Would it still seem natural to interpret the metric field of GR along substantival lines regardless of the fact that it also encodes important material properties such as energy-momentum? After bringing these questions out into the light I will cast some important doubts on the substantival (SS) interpretation of the metric field. Perhaps the metric turns out to be viewed as a relational matter field. Finally, to strengthen the relational account of spacetime I expect to remove the possible remaining interpretative tension by briefly discussing the relevance of two important facts: i) Dynamical variables are usually linked to material objects in physical theories. The metric field of GR is a dynamical object so, I claim, it should be viewed as a matter field. ii) Barbour and Bertotti (BB2, 1982) have provided and alternative formulation of classical dynamics. They provide a “genuinely relational interpretation of dynamics” (Pooley & Brown 2001). Geometry and inertia become –contra SS- relational structures in BB2

La vida desde una perspectiva física

¿Qué es la vida? Cualquier intento por definir la vida como fenómeno natural ha resultado controversial. Hay quienes incluso hoy consideran, como lo hiciera Aristóteles, que la cuestión carece de sentido ya que la vida es un hecho irreducible de la naturaleza. En los libros de texto de bióloga básica, la vida se suele definir en función de una serie de propiedades que en conjunto permiten distinguir sistemas vivos u organismos de sistemas inertes. Aunque algunas de estas propiedades –el movimiento, por ejemplo– pueden ser observadas en materia inerte, se argumenta que lo no-vivo no satisface el listado completo de propiedades

MECÁNICA CUÁNTICA ACAUSAL SOCIALMENTE DETERMINADA: REVISIÓN CRÍTICA

In his article entitledWeimar Culture; Causality and Quantum Theory, 1918-1927: Adaptation by German Physicists to a Hostile Intellectual Environment,Paul Forman intended to depict a history of the old quantum mechanicsaccording to which contemporary cultural influence turned out to bedecisive in the introduction, acceptance and assimilation of acausality withinthe theory. These statements known as the Forman thesis are placed inhistoriographic perspective; i.e. their importance is shown using the frameworkprovided by the characteristic tensions of historiography and philosophy of science. It is argued that the dilemma of determinism is essential inthis discussion. Finally, a brief critical review of the Forman thesis is offeredemphasizing some of its major weaknesses not previously discussed in theliterature.En su artículo titulado Weimar Culture; Causality and Quantum Theory,1918-1927: Adaptation by German Physicists to a Hostile IntellectualEnvironment, Paul Forman intentó dibujar una historia de la vieja mecánicacuántica según la cual la influencia cultural de la época resultó determinanteen la introducción, aceptación y asimilación de la acausalidad en esta teoría.Estas afirmaciones conocidas como las tesis de Forman, son puestas enperspectiva historiográfica, es decir, desde el panorama ofrecido por lastensiones propias de la historiografía y la filosofía de la ciencia contemporá-nea se perfila su importancia. Se argumenta que el dilema del determinismoes central en esta discusión y finalmente se presenta una breve revisióncrítica de las tesis de Forman revelando sus principales debilidades

El aumento de la masa inercial: Einstein y las coordenadas

While creating his General Theory of Relativity (GR) an the subsequent Relativistic Cosmology, Einstein hoped that his new theory of gravitation would conform to Mach¿s ideas on inertia. In doing so, he calculated two important effects that should ensure GR¿s accordance with the material origin of inertia. These effects were: (A) the increase of the inertial mass of a body when matter is piled up in its neighbourhood and (B) the dragging of inertial frames. A historical and conceptual survey of (A) is presented. While frame dragging is considered a real prediction of GR, the increase of inertial mass has been rejected as a coordinate effect. A technical survey with conceptual insights is presented.Durante los años de gestación de la Teoría General de la Relatividad (TGR) y de la subsiguiente cosmología relativista, Albert Einstein esperaba que su teoría de gravitación satisficiera las ideas de Mach sobre la inercia. Para esto calculó un par de efectos que debían garantizar la consonancia de TGR con el origen material de la inercia à la Mach. Estos efectos fueron: (A) El aumento de la masa inercial cuando se aglomera materia en su vecindad y (B) el arrastre de los marcos inerciales. En este articulo se hace un estudio histórico-conceptual del primero(A). Mientras que el arrastre es considerado como una predicción real de TGR, el aumento de la masa inercial ha llegado a desecharse como un artificio de coordenadas no impugnable a la variedad espacio-temporal estudiada. Se presenta una revisión técnica con clarificaciones conceptuales es presentada

La cuestión 31 de la Óptica o el programa de las fuerzas en la filosofía mecánica

In its final form, Newton's Optics closes its third book with 31 queries. The last one - the most extensive - is intended, among other things, to picture a universe submited to several forces. In this way, the success achieved by introducing a force acting at distance between material bodies such as universal gravitation was projected to be extended to the general set of phenomena delimited by natural philosophy. It is argued that the difficulty of this enterprise is justified by the premature condition shared by the new experimental or Baconian sciences that, unlike Principia's dynamics, would resist a rapid mathematical formalism following the Newtonian style. This is: the mediation of a force acting at distance as the key for the general synthesis of natural phenomena. A glance at Newton's query 31 allows us to follow him in his intention to investigate and to install an unifying program of the possible forces of nature.En su forma definitiva, la Óptica de Newton concluye su libro tercero con 31 cuestiones. La Cuestión 31, la más extensa, pretende, entre otras cosas, dibujar un universo sometido a la acción de fuerzas. De esta manera, el éxito que significó la introducción de una fuerza de acción a distancia entre cuerpos materiales, como la gravitación universal, pretendía ser extendido al curso del conjunto general de los fenómenos que la filosofía mecánica delimitaba como suyos. Se argumenta que la dificultad de esta empresa es justificada por el prematuro estado de gestación de las nuevas ciencias experimentales o baconianas que, a diferencia de la dinámica de los Principia, se resistirían a un rápido formalismo matemático al estilo newtoniano; esto es, a la mediación de una fuerza a distancia como clave para la síntesis general de fenómenos naturales. Una mirada, desde las palabras legadas por Newton en su cuestión 31, permite seguirle en su intención de investigar e instalar un programa de unificación de las posibles fuerzas de la naturaleza

Sobre la dinámica relacional del espaciotiempo y la conservación de la energía en la Teoría General de la Relatividad

En este artículo pretendo desmantelar la opinión generalizada según la cual una interpretación relacional del espaciotiempo no es posible. Centro mi atención en el hecho de que las variables dinámicas usualmente están asociadas a objetos materiales en las teorías físicas. El tensor métrico de la Teoría General de la Relatividad (TGR) es un objeto dinámico así que —sostengo— este debe ser mejor entendido como un campo material en toda regla. Este argumento me lleva a vincular la naturaleza relacional del espaciotiempo a las dificultades para formular una genuina ley de conservación de energía-momento en la TGR.I will try to dismantle the widespread impression that a relational account of spacetime is not possible. I concentrate on the fact that dynamical variables are usually linked to material objects in physical theories. The metric tensor field of GR is a dynamical object so, I claim, it should be viewed as a matter field. The argument links the relational ontological status of spacetime to the failure to provide a genuine law of energy-momentum conservation within General Relativity

Discos relativistas magnetostáticos contra-rotantes

Se presenta en forma detallada el modelo de contra-rotación para el estu­dio de discos delgados magnetostáticos, axialmente simétricos sin presión radial. Se encuentra una condición general para las velocidades tangen­ciales de contra-rotación, indispensable para evaluar el tensor de energía-momento superficial del disco como la superposición de dos fluidos per­fectos cargados en contra-rotación, así como expresiones para la den­sidad de energía, la presión y la densidad de corriente de los fluidos contra-rotantes. Se muestra que esta condición se satisface cuando los fluidos contra-rotantes circulan con velocidades iguales y opuestas si­guiendo electro-geodésicas. Se presentan tres ejemplos específicos donde se obtienen modelos de contra-rotación bien comportados, basados en soluciones simples de las ecuaciones de Einstein-Maxwell

DIGITAL TRANSFORMATION POLICIES: A comparative view between Chile and Colombia from a human rights perspective

The purpose of this article is to analyze comparatively the progress of the digital transformation policy of Chile and Colombia concerning international guidelines to visualize difficulties, challenges, and prospects for the implementation of public policy in Colombia. For the development of this objective, it is important to consider that the policy processes derived or adjusted after the 4.0 or digital revolution, postulate as a problem the incorporation of digitization in the concrete actions of the State and the adaptability, sensitization to government processes, an element that represents a challenge in terms of guaranteeing human rights in a highly technified context. In effect of the above, the present work is approached from a comparative methodological approach, in which the Atlas.ti and Nodexl software are used to establish the identification of patterns or differential factors between the two countries under study, allowing the correlation of characteristic elements of the policies focused on addressing the new normality or "neonormality". This allows concluding that, within the perspective raised, Colombia has not yet developed a full exercise of guarantee of rights articulated to the digitization policies, which is a challenge for the State management, as well as a strategic approach to consolidating good practices that contribute to the improvement of administrative management in the field of digitization and the generation of public value