Aspects of Determinism in Modern Physics
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At Least in Biophysical Novelties Amihud Gilead
The Twilight of Determinism: At Least in Biophysical Novelties Amihud Gilead Department of Philosophy, Eshkol Tower, University of Haifa, Haifa 3498838 Email: [email protected] Abstract. In the 1990s, Richard Lewontin referred to what appeared to be the twilight of determinism in biology. He pointed out that DNA determines only a little part of life phenomena, which are very complex. In fact, organisms determine the environment and vice versa in a nonlinear way. Very recently, biophysicists, Shimon Marom and Erez Braun, have demonstrated that controlled biophysical systems have shown a relative autonomy and flexibility in response which could not be predicted. Within the boundaries of some restraints, most of them genetic, this freedom from determinism is well maintained. Marom and Braun have challenged not only biophysical determinism but also reverse-engineering, naive reductionism, mechanism, and systems biology. Metaphysically possibly, anything actual is contingent.1 Of course, such a possibility is entirely excluded in Spinoza’s philosophy as well as in many philosophical views at present. Kant believed that anything phenomenal, namely, anything that is experimental or empirical, is inescapably subject to space, time, and categories (such as causality) which entail the undeniable validity of determinism. Both Kant and Laplace assumed that modern science, such as Newton’s physics, must rely upon such a deterministic view. According to Kant, free will is possible not in the phenomenal world, the empirical world in which we 1 This is an assumption of a full-blown metaphysics—panenmentalism—whose author is Amihud Gilead. See Gilead 1999, 2003, 2009 and 2011, including literary, psychological, and natural applications and examples —especially in chemistry —in Gilead 2009, 2010, 2013, 2014a–c, and 2015a–d. -
An Introduction to Quantum Field Theory
AN INTRODUCTION TO QUANTUM FIELD THEORY By Dr M Dasgupta University of Manchester Lecture presented at the School for Experimental High Energy Physics Students Somerville College, Oxford, September 2009 - 1 - - 2 - Contents 0 Prologue....................................................................................................... 5 1 Introduction ................................................................................................ 6 1.1 Lagrangian formalism in classical mechanics......................................... 6 1.2 Quantum mechanics................................................................................... 8 1.3 The Schrödinger picture........................................................................... 10 1.4 The Heisenberg picture............................................................................ 11 1.5 The quantum mechanical harmonic oscillator ..................................... 12 Problems .............................................................................................................. 13 2 Classical Field Theory............................................................................. 14 2.1 From N-point mechanics to field theory ............................................... 14 2.2 Relativistic field theory ............................................................................ 15 2.3 Action for a scalar field ............................................................................ 15 2.4 Plane wave solution to the Klein-Gordon equation ........................... -
Philosophy of Science and Philosophy of Chemistry
Philosophy of Science and Philosophy of Chemistry Jaap van Brakel Abstract: In this paper I assess the relation between philosophy of chemistry and (general) philosophy of science, focusing on those themes in the philoso- phy of chemistry that may bring about major revisions or extensions of cur- rent philosophy of science. Three themes can claim to make a unique contri- bution to philosophy of science: first, the variety of materials in the (natural and artificial) world; second, extending the world by making new stuff; and, third, specific features of the relations between chemistry and physics. Keywords : philosophy of science, philosophy of chemistry, interdiscourse relations, making stuff, variety of substances . 1. Introduction Chemistry is unique and distinguishes itself from all other sciences, with respect to three broad issues: • A (variety of) stuff perspective, requiring conceptual analysis of the notion of stuff or material (Sections 4 and 5). • A making stuff perspective: the transformation of stuff by chemical reaction or phase transition (Section 6). • The pivotal role of the relations between chemistry and physics in connection with the question how everything fits together (Section 7). All themes in the philosophy of chemistry can be classified in one of these three clusters or make contributions to general philosophy of science that, as yet , are not particularly different from similar contributions from other sci- ences (Section 3). I do not exclude the possibility of there being more than three clusters of philosophical issues unique to philosophy of chemistry, but I am not aware of any as yet. Moreover, highlighting the issues discussed in Sections 5-7 does not mean that issues reviewed in Section 3 are less im- portant in revising the philosophy of science. -
2008. Pruning Some Branches from 'Branching Spacetimes'
CHAPTER 10 Pruning Some Branches from “Branching Spacetimes” John Earman* Abstract Discussions of branching time and branching spacetime have become com- mon in the philosophical literature. If properly understood, these concep- tions can be harmless. But they are sometimes used in the service of debat- able and even downright pernicious doctrines. The purpose of this chapter is to identify the pernicious branching and prune it back. 1. INTRODUCTION Talk of “branching time” and “branching spacetime” is wide spread in the philo- sophical literature. Such expressions, if properly understood, can be innocuous. But they are sometimes used in the service of debatable and even downright per- nicious doctrines. The purpose of this paper is to identify the pernicious branching and prune it back. Section 2 distinguishes three types of spacetime branching: individual branch- ing, ensemble branching, and Belnap branching. Individual branching, as the name indicates, involves a branching structure in individual spacetime models. It is argued that such branching is neither necessary nor sufficient for indeterminism, which is explicated in terms of the branching in the ensemble of spacetime mod- els satisfying the laws of physics. Belnap branching refers to the sort of branching used by the Belnap school of branching spacetimes. An attempt is made to sit- uate this sort of branching with respect to ensemble branching and individual branching. Section 3 is a sustained critique of various ways of trying to imple- ment individual branching for relativistic spacetimes. Conclusions are given in Section 4. * Department of History and Philosophy of Science, University of Pittsburgh, Pittsburgh, USA The Ontology of Spacetime II © Elsevier BV ISSN 1871-1774, DOI: 10.1016/S1871-1774(08)00010-7 All rights reserved 187 188 Pruning Some Branches from “Branching Spacetimes” 2. -
On the Time Evolution of Wavefunctions in Quantum Mechanics C
On the Time Evolution of Wavefunctions in Quantum Mechanics C. David Sherrill School of Chemistry and Biochemistry Georgia Institute of Technology October 1999 1 Introduction The purpose of these notes is to help you appreciate the connection between eigenfunctions of the Hamiltonian and classical normal modes, and to help you understand the time propagator. 2 The Classical Coupled Mass Problem Here we will review the results of the coupled mass problem, Example 1.8.6 from Shankar. This is an example from classical physics which nevertheless demonstrates some of the essential features of coupled degrees of freedom in quantum mechanical problems and a general approach for removing such coupling. The problem involves two objects of equal mass, connected to two different walls andalsotoeachotherbysprings.UsingF = ma and Hooke’s Law( F = −kx) for the springs, and denoting the displacements of the two masses as x1 and x2, it is straightforward to deduce equations for the acceleration (second derivative in time,x ¨1 andx ¨2): k k x −2 x x ¨1 = m 1 + m 2 (1) k k x x − 2 x . ¨2 = m 1 m 2 (2) The goal of the problem is to solve these second-order differential equations to obtain the functions x1(t)andx2(t) describing the motion of the two masses at any given time. Since they are second-order differential equations, we need two initial conditions for each variable, i.e., x1(0), x˙ 1(0),x2(0), andx ˙ 2(0). Our two differential equations are clearly coupled,since¨x1 depends not only on x1, but also on x2 (and likewise forx ¨2). -
An S-Matrix for Massless Particles Arxiv:1911.06821V2 [Hep-Th]
An S-Matrix for Massless Particles Holmfridur Hannesdottir and Matthew D. Schwartz Department of Physics, Harvard University, Cambridge, MA 02138, USA Abstract The traditional S-matrix does not exist for theories with massless particles, such as quantum electrodynamics. The difficulty in isolating asymptotic states manifests itself as infrared divergences at each order in perturbation theory. Building on insights from the literature on coherent states and factorization, we construct an S-matrix that is free of singularities order-by-order in perturbation theory. Factorization guarantees that the asymptotic evolution in gauge theories is universal, i.e. independent of the hard process. Although the hard S-matrix element is computed between well-defined few particle Fock states, dressed/coherent states can be seen to form as intermediate states in the calculation of hard S-matrix elements. We present a framework for the perturbative calculation of hard S-matrix elements combining Lorentz-covariant Feyn- man rules for the dressed-state scattering with time-ordered perturbation theory for the asymptotic evolution. With hard cutoffs on the asymptotic Hamiltonian, the cancella- tion of divergences can be seen explicitly. In dimensional regularization, where the hard cutoffs are replaced by a renormalization scale, the contribution from the asymptotic evolution produces scaleless integrals that vanish. A number of illustrative examples are given in QED, QCD, and N = 4 super Yang-Mills theory. arXiv:1911.06821v2 [hep-th] 24 Aug 2020 Contents 1 Introduction1 2 The hard S-matrix6 2.1 SH and dressed states . .9 2.2 Computing observables using SH ........................... 11 2.3 Soft Wilson lines . 14 3 Computing the hard S-matrix 17 3.1 Asymptotic region Feynman rules . -
Ingenuity in Mathematics Ross Honsberger 10.1090/Nml/023
AMS / MAA ANNELI LAX NEW MATHEMATICAL LIBRARY VOL 23 Ingenuity in Mathematics Ross Honsberger 10.1090/nml/023 INGENUITY IN MATHEMAmCS NEW MATHEMATICAL LIBRARY PUBLISHED BY THEMATHEMATICAL ASSOCIATION OF AMERICA Editorial Committee Basil Gordon, Chairman (1975-76) Anneli Lax, Editor University of California, L.A. New York University Ivan Niven (1 975-77) University of Oregon M. M. Schiffer (1975-77) Stanford University The New Mathematical Library (NML) was begun in 1961 by the School Mathematics Study Group to make available to high school students short expository books on various topics not usually covered in the high school syllabus. In a decade the NML matured into a steadily growing series of some twenty titles of interest not only to the originally intended audience, but to college students and teachers at all levels. Previously published by Random House and L. W. Singer, the NML became a publication series of the Mathematical Association of America (MAA) in 1975. Under the auspices of the MAA the NML will continue to grow and will remain dedicated to its original and expanded purposes. INGENUITY IN MATHEMATICS by Ross Honsberger University of Waterloo, Canada 23 MATHEMATICAL ASSOCIATION OF AMERICA Illustrated by George H. Buehler Sixth Printing © Copyright 1970, by the Mathematical Association of America A11 rights reserved under International and Pan-American Copyright Conventions. Published in Washington by The Mathematical Association of America Library of Congress Catalog Card Number: 77-134351 Print ISBN 978-0-88385-623-9 Electronic ISBN 978-0-88385-938-4 Manufactured in the United States of America Note to the Reader his book is one of a series written by professional mathematicians Tin order to make some important mathematical ideas interesting and understandable to a large audience of high school students and laymen. -
Advanced Quantum Mechanics
Advanced Quantum Mechanics Rajdeep Sensarma [email protected] Quantum Dynamics Lecture #9 Schrodinger and Heisenberg Picture Time Independent Hamiltonian Schrodinger Picture: A time evolving state in the Hilbert space with time independent operators iHtˆ i@t (t) = Hˆ (t) (t) = e− (0) | i | i | i | i i✏nt Eigenbasis of Hamiltonian: Hˆ n = ✏ n (t) = cn(t) n c (t)=c (0)e− n | i | i n n | i | i n X iHtˆ iHtˆ Operators and Expectation: A(t)= (t) Aˆ (t) = (0) e Aeˆ − (0) = (0) Aˆ(t) (0) h | | i h | | i h | | i Heisenberg Picture: A static initial state and time dependent operators iHtˆ iHtˆ Aˆ(t)=e Aeˆ − Schrodinger Picture Heisenberg Picture (0) (t) (0) (0) | i!| i | i!| i Equivalent description iHtˆ iHtˆ Aˆ Aˆ Aˆ Aˆ(t)=e Aeˆ − ! ! of a quantum system i@ (t) = Hˆ (t) i@ Aˆ(t)=[Aˆ(t), Hˆ ] t| i | i t Time Evolution and Propagator iHtˆ (t) = e− (0) Time Evolution Operator | i | i (x, t)= x (t) = x Uˆ(t) (0) = dx0 x Uˆ(t) x0 x0 (0) h | i h | | i h | | ih | i Z Propagator: Example : Free Particle The propagator satisfies and hence is often called the Green’s function Retarded and Advanced Propagator The following propagators are useful in different contexts Retarded or Causal Propagator: This propagates states forward in time for t > t’ Advanced or Anti-Causal Propagator: This propagates states backward in time for t < t’ Both the retarded and the advanced propagator satisfies the same diff. eqn., but with different boundary conditions Propagators in Frequency Space Energy Eigenbasis |n> The integral is ill defined due to oscillatory nature -
The Liouville Equation in Atmospheric Predictability
The Liouville Equation in Atmospheric Predictability Martin Ehrendorfer Institut fur¨ Meteorologie und Geophysik, Universitat¨ Innsbruck Innrain 52, A–6020 Innsbruck, Austria [email protected] 1 Introduction and Motivation It is widely recognized that weather forecasts made with dynamical models of the atmosphere are in- herently uncertain. Such uncertainty of forecasts produced with numerical weather prediction (NWP) models arises primarily from two sources: namely, from imperfect knowledge of the initial model condi- tions and from imperfections in the model formulation itself. The recognition of the potential importance of accurate initial model conditions and an accurate model formulation dates back to times even prior to operational NWP (Bjerknes 1904; Thompson 1957). In the context of NWP, the importance of these error sources in degrading the quality of forecasts was demonstrated to arise because errors introduced in atmospheric models, are, in general, growing (Lorenz 1982; Lorenz 1963; Lorenz 1993), which at the same time implies that the predictability of the atmosphere is subject to limitations (see, Errico et al. 2002). An example of the amplification of small errors in the initial conditions, or, equivalently, the di- vergence of initially nearby trajectories is given in Fig. 1, for the system discussed by Lorenz (1984). The uncertainty introduced into forecasts through uncertain initial model conditions, and uncertainties in model formulations, has been the subject of numerous studies carried out in parallel to the continuous development of NWP models (e.g., Leith 1974; Epstein 1969; Palmer 2000). In addition to studying the intrinsic predictability of the atmosphere (e.g., Lorenz 1969a; Lorenz 1969b; Thompson 1985a; Thompson 1985b), efforts have been directed at the quantification or predic- tion of forecast uncertainty that arises due to the sources of uncertainty mentioned above (see the review papers by Ehrendorfer 1997 and Palmer 2000, and Ehrendorfer 1999). -
Machine Guessing – I
Machine Guessing { I David Miller Department of Philosophy University of Warwick COVENTRY CV4 7AL UK e-mail: [email protected] ⃝c copyright D. W. Miller 2011{2018 Abstract According to Karl Popper, the evolution of science, logically, methodologically, and even psy- chologically, is an involved interplay of acute conjectures and blunt refutations. Like biological evolution, it is an endless round of blind variation and selective retention. But unlike biological evolution, it incorporates, at the stage of selection, the use of reason. Part I of this two-part paper begins by repudiating the common beliefs that Hume's problem of induction, which com- pellingly confutes the thesis that science is rational in the way that most people think that it is rational, can be solved by assuming that science is rational, or by assuming that Hume was irrational (that is, by ignoring his argument). The problem of induction can be solved only by a non-authoritarian theory of rationality. It is shown also that because hypotheses cannot be distilled directly from experience, all knowledge is eventually dependent on blind conjecture, and therefore itself conjectural. In particular, the use of rules of inference, or of good or bad rules for generating conjectures, is conjectural. Part II of the paper expounds a form of Popper's critical rationalism that locates the rationality of science entirely in the deductive processes by which conjectures are criticized and improved. But extreme forms of deductivism are rejected. The paper concludes with a sharp dismissal of the view that work in artificial intelligence, including the JSM method cultivated extensively by Victor Finn, does anything to upset critical rationalism. -
Body, Mind and Spirit—Philosophical Reflections for Researching
education sciences Article Body, Mind and Spirit—Philosophical Reflections for Researching Education about the Holocaust Katalin Eszter Morgan Historisches Institut, Fakultät für Geisteswissenschaften, Universität Duisburg-Essen, Campus Essen, Universitätsstr, 12 45117 Essen, Germany; [email protected], Tel.: +49-201-183-7395 Received: 14 August 2017; Accepted: 14 September 2017; Published: 20 September 2017 Abstract: This reflective essay draws a sketch of the theoretical and philosophical foundations in preparation for conducting a research project that investigates how German school learners deal with the memories of Shoah survivors. The essay explores some communication challenges and opportunities presented by the use of the double linguistic medium—German and English. The central philosophical argument is that there is a conceptual conflation of and confusion around the word Geist (spirit/mind), and that the difference between the spirit and the mind needs to be explored and clarified. For this purpose Hegel’s thoughts on the spirit are considered and related to theories of memory. Also, Theodor Lessing’s reflections on the origins of hatred are touched upon, which he traces back to the splitting of the spirit from the mind. How the body, mind and spirit work together is highlighted with a biographical example of a descendant of a Nazi perpetrator. By way of conclusion, the philosophical and methodological implications for researching education about the Shoah are briefly discussed. Keywords: education about the holocaust; Hegel; spirit; mind; Geist; memory; language 1. Introduction This essay sketches out some theoretical and philosophical ideas in preparation for conducting a research project that investigates how learners deal with the memories of Holocaust survivors in German schools. -
The Virtues of Ingenuity: Reasoning and Arguing Without Bias
Topoi DOI 10.1007/s11245-013-9174-y The Virtues of Ingenuity: Reasoning and Arguing without Bias Olivier Morin Ó Springer Science+Business Media Dordrecht 2013 Abstract This paper describes and defends the ‘‘virtues Ingenuity is the use of reasoning to gather information of ingenuity’’: detachment, lucidity, thoroughness. Philos- and to solve problems. This paper is about its virtues,in ophers traditionally praise these virtues for their role in the both senses of the term: the things that ingenuity is good practice of using reasoning to solve problems and gather for, and the qualities that it takes to be good at it. The information. Yet, reasoning has other, no less important philosophical tradition, particularly since Bacon and uses. Conviction is one of them. A recent revival of rhet- Descartes, has praised detachment, freedom from pre- oric and argumentative approaches to reasoning (in psy- judice, and objectivity, in terms that may sound quaintly chology, philosophy and science studies) has highlighted excessive today. The celebration of ingenuity often went the virtues of persuasiveness and cast a new light on some along with a demotion of other uses of reasoning. Con- of its apparent vices—bad faith, deluded confidence, con- viction, or persuasion—the use of reasoning to change firmation and myside biases. Those traits, it is often argued, other people’s minds—was one of them. Conviction and will no longer look so detrimental once we grasp their ingenuity arguably require different dispositions: a con- proper function: arguing in order to persuade, rather than vincing argumentation benefits from a sensitivity to other thinking in order to solve problems.