scholarly journals Fundamental and Emergent Geometry in Newtonian Physics

2020 ◽  
Vol 71 (1) ◽  
pp. 1-32 ◽  
Author(s):  
David Wallace
Keyword(s):  
Newtonian Physics ◽  
Emergent Geometry

Big Decisions: Opting, Converting, Drifting

2006 ◽  
Vol 58 ◽  
pp. 157-172 ◽  
Author(s):  
Edna Ullmann-Margalit
Keyword(s):  
Decision Theory ◽  
Rational Choice ◽  
Practical Reasoning ◽  
Outer Space ◽  
Atomic Level ◽  
Social Scientists ◽  
Newtonian Physics ◽  
The Social ◽  
Separate Treatment ◽  
The One

I want to focus on some of the limits of decision theory that are of interest to the philosophical concern with practical reasoning and rational choice. These limits should also be of interest to the social-scientists' concern with Rational Choice.Let me start with an analogy. Classical Newtonian physics holds good and valid for middle-sized objects, but not for the phenomena of the very little, micro, sub-atomic level or the very large, macro, outer-space level: different theories, concepts and laws apply there. Similarly, I suggest that we might think of the theory of decisionmaking as relating to middle-sized, ordinary decisions, and to them only. There remain the two extremes, the very ‘small’ decisions on the one hand and the very ‘big’ decisions on the other. These may pose a challenge to the ordinary decision theory and may consequently require a separate treatment.

scholarly journals Gauging the higher-spin-like symmetries by the Moyal product

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
M. Cvitan ◽  
P. Dominis Prester ◽  
S. Giaccari ◽  
M. Paulišić ◽  
I. Vuković
Keyword(s):  
Linear Connection ◽  
Covariant Formulation ◽  
Formal Similarity ◽  
Commutative Field ◽  
Gauge Transformations ◽  
Yang Mills ◽  
Higher Derivative ◽  
Novel Approach ◽  
Emergent Geometry ◽  
Higher Spin

Abstract We analyze a novel approach to gauging rigid higher derivative (higher spin) symmetries of free relativistic actions defined on flat spacetime, building on the formalism originally developed by Bonora et al. and Bekaert et al. in their studies of linear coupling of matter fields to an infinite tower of higher spin fields. The off-shell definition is based on fields defined on a 2d-dimensional master space equipped with a symplectic structure, where the infinite dimensional Lie algebra of gauge transformations is given by the Moyal commutator. Using this algebra we construct well-defined weakly non-local actions, both in the gauge and the matter sector, by mimicking the Yang-Mills procedure. The theory allows for a description in terms of an infinite tower of higher spin spacetime fields only on-shell. Interestingly, Euclidean theory allows for such a description also off-shell. Owing to its formal similarity to non-commutative field theories, the formalism allows for the introduction of a covariant potential which plays the role of the generalised vielbein. This covariant formulation uncovers the existence of other phases and shows that the theory can be written in a matrix model form. The symmetries of the theory are analyzed and conserved currents are explicitly constructed. By studying the spin-2 sector we show that the emergent geometry is closely related to teleparallel geometry, in the sense that the induced linear connection is opposite to Weitzenböck’s.

scholarly journals Determinism

2021 ◽  
Vol 20 (5) ◽  
pp. 1-34
Author(s):  
Edward A. Lee
Keyword(s):  
Quantum Physics ◽  
Deterministic Model ◽  
Physical World ◽  
Deterministic Models ◽  
Newtonian Physics ◽  
Physical Systems ◽  
Newton’S Laws ◽  
And Behavior

This article is about deterministic models, what they are, why they are useful, and what their limitations are. First, the article emphasizes that determinism is a property of models, not of physical systems. Whether a model is deterministic or not depends on how one defines the inputs and behavior of the model. To define behavior, one has to define an observer. The article compares and contrasts two classes of ways to define an observer, one based on the notion of “state” and another that more flexibly defines the observables. The notion of “state” is shown to be problematic and lead to nondeterminism that is avoided when the observables are defined differently. The article examines determinism in models of the physical world. In what may surprise many readers, it shows that Newtonian physics admits nondeterminism and that quantum physics may be interpreted as a deterministic model. Moreover, it shows that both relativity and quantum physics undermine the notion of “state” and therefore require more flexible ways of defining observables. Finally, the article reviews results showing that sufficiently rich sets of deterministic models are incomplete. Specifically, nondeterminism is inescapable in any system of models rich enough to encompass Newton’s laws.

scholarly journals Natureza, Individuação e Logos em Merleau-Ponty

2006 ◽  
Vol 51 (2) ◽  
Author(s):  
Osvaldo Fontes Filho
Keyword(s):  
Key Words ◽  
Time And Space ◽  
Newtonian Physics ◽  
Causal Chains ◽  
Ontological Sense

Este estudo sintetiza as leituras de Merleu-Ponty sobre a ciência moderna, e procura esclarecer como elas desautorizam uma concepção determinista da Natureza. Ao contrário da física newtoniana e de outras ontologias substancialistas, que submetem a contingência ao entendimento, Merleau-Ponty desvela um registro do descontínuo, onde os seres reduzem-se a “feixe de probabilidades”. Assim, ao fornecer sentido ontológico ao polimorfismo do tempo e do espaço percebidos, Merleau-Ponty intercepta em teóricos pós-newtonianos renovada concepção da matéria: “éter dos acontecimentos”, ela se esclarece menos pelas longas cadeias causais que pela “pululação ilimitada das categorias”. A conseqüente refutação dos princípios de identidade é oportunidade para investir individualidades em devir e modos de existência ubiqüitários, atestados pelas modernas embriologias, elementos que ajudam a reformular o cenário ontológico. PALAVRAS-CHAVE – Natureza. Ciência. Acontecimento. Individualidade. Ontologia. ABSTRACT This paper summarizes Merleau- Ponty lectures about modern sciences and tries to enlighten how he disavows a determinist conception of Nature. Adversely to Newtonian physics and others substantialistic ontologies that translate contingency into understanding, Merleau- Ponty reveals a register of discontinuity in Nature where beings amount to be a “bundle.of probabilities”. Therefore, in getting ontological sense to the polymorphism of perceived time and space, Merleau-Ponty identifies in post- Newtonian theorists a renewed conception of matter as “ether of events”. Matter do not have to be shaped by long causal chains but by “unlimited profusion of categories”. A consequent refusal of identity principles is an opportunity to a close examination of individualities in progress and ubiquitous ways of existence, both attested by moderns embryologies. In doing so, Merleau-Ponty aims to reformulate ontological scene. KEY WORDS – Nature, science, event, individuality, ontology.

scholarly journals Quantum gravity as a multitrace matrix model

2017 ◽  
Vol 32 (31) ◽  
pp. 1750180
Author(s):  
Badis Ydri ◽  
Cherine Soudani ◽  
Ahlam Rouag
Keyword(s):  
Quantum Gravity ◽  
Matrix Models ◽  
Large Class ◽  
Matrix Model ◽  
Two Dimensions ◽  
Two Dimensional ◽  
Topology Change ◽  
New Model ◽  
And Topology ◽  
Emergent Geometry

We present a new model of quantum gravity as a theory of random geometries given explicitly in terms of a multitrace matrix model. This is a generalization of the usual discretized random surfaces of two-dimensional quantum gravity which works away from two dimensions and captures a large class of spaces admitting a finite spectral triple. These multitrace matrix models sustain emergent geometry as well as growing dimensions and topology change.

Visual Perception of Apparent Motion Abides by Minimization Principles of Geometry

2021 ◽  
Author(s):  
Yaxin Liu ◽  
Stella F. Lourenco
Keyword(s):  
Visual Perception ◽  
Target Detection ◽  
Apparent Motion ◽  
Visual Space ◽  
Detection Task ◽  
Newtonian Physics ◽  
Kinematic Geometry ◽  
Shed Light ◽  
Target Detection Task ◽  
Perceptual Phenomenon

Apparent motion is a robust perceptual phenomenon in which observers perceive a stimulus traversing the vacant visual space between two flashed stimuli. Although it is known that the “filling-in” of apparent motion favors the simplest and most economical path, the interpolative computations remain poorly understood. Here, we tested whether the perception of apparent motion is best characterized by Newtonian physics or kinematic geometry. Participants completed a target detection task while Pacmen- shaped objects were presented in succession to create the perception of apparent motion. We found that target detection was impaired when apparent motion, as predicted by kinematic geometry, not Newtonian physics, obstructed the target’s location. Our findings shed light on the computations employed by the visual system, suggesting specifically that the “filling-in” perception of apparent motion may be dominated by kinematic geometry, not Newtonian physics.

Virtual-Reality graph visualization based on Fruchterman-Reingold using Unity and SteamVR

2021 ◽  
pp. 147387162110603
Author(s):  
Gerd Kortemeyer
Keyword(s):  
Virtual Reality ◽  
Directed Graphs ◽  
Dynamic Visualization ◽  
Graph Visualization ◽  
Weighted Graphs ◽  
Virtual Reality System ◽  
Newtonian Physics ◽  
Dynamic Extrusion ◽  
Relationship Of ◽  
The Relationship

The paper describes a method for the immersive, dynamic visualization of undirected, weighted graphs. Using the Fruchterman-Reingold method, force-directed graphs are drawn in a Virtual-Reality system. The user can walk through the data, as well as move vertices using controllers, while the network display rearranges in realtime according to Newtonian physics. In addition to the physics behind the employed method, the paper explains the most pertinent computational mechanisms for its implementation, using Unity, SteamVR, and a Virtual-Reality system such as HTC Vive (the source package is made available for download). It was found that the method allows for intuitive exploration of graphs with on the order of [Formula: see text] vertices, and that dynamic extrusion of vertices and realtime readjustment of the network structure allows for developing an intuitive understanding of the relationship of a vertex to the remainder of the network. Based on this observation, possible future developments are suggested.

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