A Brief Introduction to Temporality and Causality
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Introduction to Dynamical Triangulations
Introduction to Dynamical Triangulations Andrzej G¨orlich Niels Bohr Institute, University of Copenhagen Naxos, September 12th, 2011 Andrzej G¨orlich Causal Dynamical Triangulation Outline 1 Path integral for quantum gravity 2 Causal Dynamical Triangulations 3 Numerical setup 4 Phase diagram 5 Background geometry 6 Quantum fluctuations Andrzej G¨orlich Causal Dynamical Triangulation Path integral formulation of quantum mechanics A classical particle follows a unique trajectory. Quantum mechanics can be described by Path Integrals: All possible trajectories contribute to the transition amplitude. To define the functional integral, we discretize the time coordinate and approximate each path by linear pieces. space classical trajectory t1 time t2 Andrzej G¨orlich Causal Dynamical Triangulation Path integral formulation of quantum mechanics A classical particle follows a unique trajectory. Quantum mechanics can be described by Path Integrals: All possible trajectories contribute to the transition amplitude. To define the functional integral, we discretize the time coordinate and approximate each path by linear pieces. quantum trajectory space classical trajectory t1 time t2 Andrzej G¨orlich Causal Dynamical Triangulation Path integral formulation of quantum mechanics A classical particle follows a unique trajectory. Quantum mechanics can be described by Path Integrals: All possible trajectories contribute to the transition amplitude. To define the functional integral, we discretize the time coordinate and approximate each path by linear pieces. quantum trajectory space classical trajectory t1 time t2 Andrzej G¨orlich Causal Dynamical Triangulation Path integral formulation of quantum gravity General Relativity: gravity is encoded in space-time geometry. The role of a trajectory plays now the geometry of four-dimensional space-time. All space-time histories contribute to the transition amplitude. -
Causality and Determinism: Tension, Or Outright Conflict?
1 Causality and Determinism: Tension, or Outright Conflict? Carl Hoefer ICREA and Universidad Autònoma de Barcelona Draft October 2004 Abstract: In the philosophical tradition, the notions of determinism and causality are strongly linked: it is assumed that in a world of deterministic laws, causality may be said to reign supreme; and in any world where the causality is strong enough, determinism must hold. I will show that these alleged linkages are based on mistakes, and in fact get things almost completely wrong. In a deterministic world that is anything like ours, there is no room for genuine causation. Though there may be stable enough macro-level regularities to serve the purposes of human agents, the sense of “causality” that can be maintained is one that will at best satisfy Humeans and pragmatists, not causal fundamentalists. Introduction. There has been a strong tendency in the philosophical literature to conflate determinism and causality, or at the very least, to see the former as a particularly strong form of the latter. The tendency persists even today. When the editors of the Stanford Encyclopedia of Philosophy asked me to write the entry on determinism, I found that the title was to be “Causal determinism”.1 I therefore felt obliged to point out in the opening paragraph that determinism actually has little or nothing to do with causation; for the philosophical tradition has it all wrong. What I hope to show in this paper is that, in fact, in a complex world such as the one we inhabit, determinism and genuine causality are probably incompatible with each other. -
Observational Determinism for Concurrent Program Security
Observational Determinism for Concurrent Program Security Steve Zdancewic Andrew C. Myers Department of Computer and Information Science Computer Science Department University of Pennsylvania Cornell University [email protected] [email protected] Abstract This paper makes two contributions. First, it presents a definition of information-flow security that is appropriate for Noninterference is a property of sequential programs that concurrent systems. Second, it describes a simple but ex- is useful for expressing security policies for data confiden- pressive concurrent language with a type system that prov- tiality and integrity. However, extending noninterference to ably enforces security. concurrent programs has proved problematic. In this pa- Notions of secure information flow are usually based on per we present a relatively expressive secure concurrent lan- noninterference [15], a property only defined for determin- guage. This language, based on existing concurrent calculi, istic systems. Intuitively, noninterference requires that the provides first-class channels, higher-order functions, and an publicly visible results of a computation do not depend on unbounded number of threads. Well-typed programs obey a confidential (or secret) information. Generalizing noninter- generalization of noninterference that ensures immunity to ference to concurrent languages is problematic because these internal timing attacks and to attacks that exploit informa- languages are naturally nondeterministic: the order of execu- tion about the thread scheduler. Elimination of these refine- tion of concurrent threads is not specified by the language se- ment attacks is possible because the enforced security prop- mantics. Although this nondeterminism permits a variety of erty extends noninterference with observational determin- thread scheduler implementations, it also leads to refinement ism. -
Causality in Quantum Field Theory with Classical Sources
Causality in Quantum Field Theory with Classical Sources Bo-Sture K. Skagerstam1;a), Karl-Erik Eriksson2;b), Per K. Rekdal3;c) a)Department of Physics, NTNU, Norwegian University of Science and Technology, N-7491 Trondheim, Norway b) Department of Space, Earth and Environment, Chalmers University of Technology, SE-412 96 G¨oteborg, Sweden c)Molde University College, P.O. Box 2110, N-6402 Molde, Norway Abstract In an exact quantum-mechanical framework we show that space-time expectation values of the second-quantized electromagnetic fields in the Coulomb gauge, in the presence of a classical source, automatically lead to causal and properly retarded elec- tromagnetic field strengths. The classical ~-independent and gauge invariant Maxwell's equations then naturally emerge and are therefore also consistent with the classical spe- cial theory of relativity. The fundamental difference between interference phenomena due to the linear nature of the classical Maxwell theory as considered in, e.g., classical optics, and interference effects of quantum states is clarified. In addition to these is- sues, the framework outlined also provides for a simple approach to invariance under time-reversal, some spontaneous photon emission and/or absorption processes as well as an approach to Vavilov-Cherenkovˇ radiation. The inherent and necessary quan- tum uncertainty, limiting a precise space-time knowledge of expectation values of the quantum fields considered, is, finally, recalled. arXiv:1801.09947v2 [quant-ph] 30 Mar 2019 1Corresponding author. Email address: [email protected] 2Email address: [email protected] 3Email address: [email protected] 1. Introduction The roles of causality and retardation in classical and quantum-mechanical versions of electrodynamics are issues that one encounters in various contexts (for recent discussions see, e.g., Refs.[1]-[14]). -
1.) What Is the Difference Between Observation and Interpretation? Write a Short Paragraph in Your Journal (5-6 Sentences) Defining Both, with One Example Each
Observation and Response: Creative Response Template can be adapted to fit a variety of classes and types of responses Goals: Students will: • Practice observation skills and develop their abilities to find multiple possibilities for interpretation and response to visual material; • Consider the difference between observation and interpretation; • Develop descriptive skills, including close reading and metaphorical description; • Develop research skills by considering a visual text or object as a primary source; • Engage in creative response to access and communicate intellectually or emotionally challenging material. Observation exercises Part I You will keep a journal as you go through this exercise. This can be a physical notebook that pleases you or a word document on your computer. At junctures during the exercise, you will be asked to comment, define, reflect, and create in your journal on what you just did. Journal responses will be posted to Canvas at the conclusion of the exercise, either as word documents or as Jpegs. 1.) What is the difference between observation and interpretation? Write a short paragraph in your journal (5-6 sentences) defining both, with one example each. 2.) Set a timer on your phone or computer (or oven…) and observe the image provided for 1 minute. Quickly write a preliminary research question about it. At first glance, what are you curious about? What do you want to know? 3.) Set your timer for 5 minutes and write as many observations as possible about it. Try to keep making observations, even when you feel stuck. Keep returning to the question, “What do I see?” No observation is too big or too small, too obvious or too obscure. -
Time and Causality in General Relativity
Time and Causality in General Relativity Ettore Minguzzi Universit`aDegli Studi Di Firenze FQXi International Conference. Ponta Delgada, July 10, 2009 FQXi Conference 2009, Ponta Delgada Time and Causality in General Relativity 1/8 Light cone A tangent vector v 2 TM is timelike, lightlike, causal or spacelike if g(v; v) <; =; ≤; > 0 respectively. Time orientation and spacetime At every point there are two cones of timelike vectors. The Lorentzian manifold is time orientable if a continuous choice of one of the cones, termed future, can be made. If such a choice has been made the Lorentzian manifold is time oriented and is also called spacetime. Lorentzian manifolds and light cones Lorentzian manifolds A Lorentzian manifold is a Hausdorff manifold M, of dimension n ≥ 2, endowed with a Lorentzian metric, that is a section g of T ∗M ⊗ T ∗M with signature (−; +;:::; +). FQXi Conference 2009, Ponta Delgada Time and Causality in General Relativity 2/8 Time orientation and spacetime At every point there are two cones of timelike vectors. The Lorentzian manifold is time orientable if a continuous choice of one of the cones, termed future, can be made. If such a choice has been made the Lorentzian manifold is time oriented and is also called spacetime. Lorentzian manifolds and light cones Lorentzian manifolds A Lorentzian manifold is a Hausdorff manifold M, of dimension n ≥ 2, endowed with a Lorentzian metric, that is a section g of T ∗M ⊗ T ∗M with signature (−; +;:::; +). Light cone A tangent vector v 2 TM is timelike, lightlike, causal or spacelike if g(v; v) <; =; ≤; > 0 respectively. -
Studies on Causal Explanation in Naturalistic Philosophy of Mind
tn tn+1 s s* r1 r2 r1* r2* Interactions and Exclusions: Studies on Causal Explanation in Naturalistic Philosophy of Mind Tuomas K. Pernu Department of Biosciences Faculty of Biological and Environmental Sciences & Department of Philosophy, History, Culture and Art Studies Faculty of Arts ACADEMIC DISSERTATION To be publicly discussed, by due permission of the Faculty of Arts at the University of Helsinki, in lecture room 5 of the University of Helsinki Main Building, on the 30th of November, 2013, at 12 o’clock noon. © 2013 Tuomas Pernu (cover figure and introductory essay) © 2008 Springer Science+Business Media (article I) © 2011 Walter de Gruyter (article II) © 2013 Springer Science+Business Media (article III) © 2013 Taylor & Francis (article IV) © 2013 Open Society Foundation (article V) Layout and technical assistance by Aleksi Salokannel | SI SIN Cover layout by Anita Tienhaara Author’s address: Department of Biosciences Division of Physiology and Neuroscience P.O. Box 65 FI-00014 UNIVERSITY OF HELSINKI e-mail [email protected] ISBN 978-952-10-9439-2 (paperback) ISBN 978-952-10-9440-8 (PDF) ISSN 1799-7372 Nord Print Helsinki 2013 If it isn’t literally true that my wanting is causally responsible for my reaching, and my itching is causally responsible for my scratching, and my believing is causally responsible for my saying … , if none of that is literally true, then practically everything I believe about anything is false and it’s the end of the world. Jerry Fodor “Making mind matter more” (1989) Supervised by Docent Markus -
Causation As Folk Science
1. Introduction Each of the individual sciences seeks to comprehend the processes of the natural world in some narrow do- main—chemistry, the chemical processes; biology, living processes; and so on. It is widely held, however, that all the sciences are unified at a deeper level in that natural processes are governed, at least in significant measure, by cause and effect. Their presence is routinely asserted in a law of causa- tion or principle of causality—roughly, that every effect is produced through lawful necessity by a cause—and our ac- counts of the natural world are expected to conform to it.1 My purpose in this paper is to take issue with this view of causation as the underlying principle of all natural processes. Causation I have a negative and a positive thesis. In the negative thesis I urge that the concepts of cause as Folk Science and effect are not the fundamental concepts of our science and that science is not governed by a law or principle of cau- sality. This is not to say that causal talk is meaningless or useless—far from it. Such talk remains a most helpful way of conceiving the world, and I will shortly try to explain how John D. Norton that is possible. What I do deny is that the task of science is to find the particular expressions of some fundamental causal principle in the domain of each of the sciences. My argument will be that centuries of failed attempts to formu- late a principle of causality, robustly true under the introduc- 1Some versions are: Kant (1933, p.218) "All alterations take place in con- formity with the law of the connection of cause and effect"; "Everything that happens, that is, begins to be, presupposes something upon which it follows ac- cording to a rule." Mill (1872, Bk. -
Causality in the Quantum World
VIEWPOINT Causality in the Quantum World A new model extends the definition of causality to quantum-mechanical systems. by Jacques Pienaar∗ athematical models for deducing cause-effect relationships from statistical data have been successful in diverse areas of science (see Ref. [1] and references therein). Such models can Mbe applied, for instance, to establish causal relationships between smoking and cancer or to analyze risks in con- struction projects. Can similar models be extended to the microscopic world governed by the laws of quantum me- chanics? Answering this question could lead to advances in quantum information and to a better understanding of the foundations of quantum mechanics. Developing quantum Figure 1: In statistics, causal models can be used to extract extensions of causal models, however, has proven challeng- cause-effect relationships from empirical data on a complex ing because of the peculiar features of quantum mechanics. system. Existing models, however, do not apply if at least one For instance, if two or more quantum systems are entangled, component of the system (Y) is quantum. Allen et al. have now it is hard to deduce whether statistical correlations between proposed a quantum extension of causal models. (APS/Alan them imply a cause-effect relationship. John-Mark Allen at Stonebraker) the University of Oxford, UK, and colleagues have now pro- posed a quantum causal model based on a generalization of an old principle known as Reichenbach’s common cause is a third variable that is a common cause of both. In the principle [2]. latter case, the correlation will disappear if probabilities are Historically, statisticians thought that all information conditioned to the common cause. -
PDF Download Starting with Science Strategies for Introducing Young Children to Inquiry 1St Edition Ebook
STARTING WITH SCIENCE STRATEGIES FOR INTRODUCING YOUNG CHILDREN TO INQUIRY 1ST EDITION PDF, EPUB, EBOOK Marcia Talhelm Edson | 9781571108074 | | | | | Starting with Science Strategies for Introducing Young Children to Inquiry 1st edition PDF Book The presentation of the material is as good as the material utilizing star trek analogies, ancient wisdom and literature and so much more. Using Multivariate Statistics. Michael Gramling examines the impact of policy on practice in early childhood education. Part of a series on. Schauble and colleagues , for example, found that fifth grade students designed better experiments after instruction about the purpose of experimentation. For example, some suggest that learning about NoS enables children to understand the tentative and developmental NoS and science as a human activity, which makes science more interesting for children to learn Abd-El-Khalick a ; Driver et al. Research on teaching and learning of nature of science. The authors begin with theory in a cultural context as a foundation. What makes professional development effective? Frequently, the term NoS is utilised when considering matters about science. This book is a documentary account of a young intern who worked in the Reggio system in Italy and how she brought this pedagogy home to her school in St. Taking Science to School answers such questions as:. The content of the inquiries in science in the professional development programme was based on the different strands of the primary science curriculum, namely Living Things, Energy and Forces, Materials and Environmental Awareness and Care DES Exit interview. Begin to address the necessity of understanding other usually peer positions before they can discuss or comment on those positions. -
Discovery of Causal Time Intervals
Discovery of Causal Time Intervals Zhenhui Li∗ Guanjie Zheng∗ Amal Agarwaly Lingzhou Xuey Thomas Lauvauxz Abstract Granger test X causes Y: rejected Causality analysis, beyond \mere" correlations, has be- X[t0:t1] causes Y[t0:t1]: accepted come increasingly important for scientific discoveries X and policy decisions. Many of these real-world appli- cations involve time series data. A key observation is Y that the causality between time series could vary signif- icantly over time. For example, a rain could cause severe t0 t1 time traffic jams during the rush hours, but has little impact on the traffic at midnight. However, previous studies Figure 1: An example illustrating the causality in mostly look at the whole time series when determining partial time series. The original Granger test fails to the causal relationship between them. Instead, we pro- detect the causal relationship, since X causes Y only pose to detect the partial time intervals with causality. during the time interval [t0 : t1]. Our goal is to find As it is time consuming to enumerate all time intervals such time intervals. and test causality for each interval, we further propose an efficient algorithm that can avoid unnecessary com- causes Y by Granger test if the full model is significantly putations based on the bounds of F -test in the Granger better than the reduced model (i.e., it is critical to use causality test. We use both synthetic datasets and real the values of X to predict Y ). datasets to demonstrate the efficiency of our pruning However, in real-world scenarios, causal relation- techniques and that our method can effectively discover ships may exist only in partial time series. -
Principles of Scientific Inquiry
Chapter 2 PRINCIPLES OF SCIENTIFIC INQUIRY Introduction This chapter provides a summary of the principles of scientific inquiry. The purpose is to explain terminology, and introduce concepts, which are explained more completely in later chapters. Much of the content has been based on explanations and examples given by Wilson (1). The Scientific Method Although most of us have heard, at some time in our careers, that research must be carried out according to “the scientific method”, there is no single, scientific method. The term is usually used to mean a systematic approach to solving a problem in science. Three types of investigation, or method, can be recognized: · The Observational Method · The Experimental (and quasi-experimental) Methods, and · The Survey Method. The observational method is most common in the natural sciences, especially in fields such as biology, geology and environmental science. It involves recording observations according to a plan, which prescribes what information to collect, where it should be sought, and how it should be recorded. In the observational method, the researcher does not control any of the variables. In fact, it is important that the research be carried out in such a manner that the investigations do not change the behaviour of what is being observed. Errors introduced as a result of observing a phenomenon are known as systematic errors because they apply to all observations. Once a valid statistical sample (see Chapter Four) of observations has been recorded, the researcher analyzes and interprets the data, and develops a theory or hypothesis, which explains the observations. The experimental method begins with a hypothesis.