DOCSLIB.ORG

Experimental Realization of Popper's Experiment: Violation of The

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Experimental Realization of Popper's Experiment: Violation of The CORE Metadata, citation and similar papers at core.ac.uk Provided by CERN Document Server Experimental realization of Popper's Experiment: Violation of the Uncertainty Principle? Yoon-Ho Kim∗ and Yanhua Shihy Department of Physics University of Maryland, Baltimore County Baltimore, Maryland 21250, U.S.A. (Revised 19 October 1999, to appear in Foundations of Physics) from EPR’s gedankenexperiment, the physics community An entangled pair of photons (1 and 2) are emitted to remained ignorant of Popper’s experiment. opposite directions. A narrow slit is placed in the path of In this paper we wish to report a recent realization photon 1 to provide the precise knowledge of its position on of Popper’s thought experiment. Indeed, it is astonish- the -axis and this also determines the precise -position of y y ing to see that the experimental results agree with Pop- its twin, photon 2, due to quantum entanglement. Is photon 2 per’s prediction. Through quantum entanglement one going to experience a greater uncertainty in momentum, that may learn the precise knowledge of a photon’s position is, a greater ∆p because of the precise knowledge of its posi- y and would therefore expect a greater uncertainty in its tion y? The experimental data show ∆y∆py <hfor photon 2. Can this recent realization of the thought experiment of momentum under the usual Copenhagen interpretation Karl Popper signal a violation of the uncertainty principle? of the uncertainty relations. However, the measurement shows that the momentum does not experience a corre- sponding increase of uncertainty. Is this a violation of the uncertainty principle? As a matter of fact, one should not be surprised with the experimental result and should not consider this ques- I. INTRODUCTION tion as a new challenge. Similar results have been demon- strated in EPR type of experiments and the same ques- Uncertainty, one of the basic principles of quantum me- tion has been asked in EPR’s 1935 paper [2]. In the past chanics, distinguishes the world of quantum phenomena decades, we have been worrying about problems concern- from the realm of classical physics. Quantum mechani- ing causality, locality, and reality more than the “crux” cally, one can never expect to measure both the precise of the EPR paradox itself: the uncertainty principle. position and momentum of a particle at the same time. It is prohibited. We say that the quantum observables “position” and “momentum” are “complementary” be- II. POPPER'S EXPERIMENT cause the precise knowledge of the position (momentum) implies that all possible outcomes of measuring the mo- Similar to the EPR’s gedankenexperiment, Popper’s ex- mentum (position) are equally probable. periment is also based on the feature of two-particle en- Karl Popper, being a “metaphysical realist”, however tanglement. Quantum mechanics allows the entangled took a different point of view. In his opinion, the quan- EPR-type state, a state in which if the position or mo- tum formalism could and should be interpreted realisti- mentum of particle 1 is known the corresponding ob- cally: a particle must have precise position and momen- servable of its twin, particle 2, is then 100% determined tum, which shares the same view as Einstein. In this re- [2]. Popper’s original thought experiment is schemati- gard he invented a thought experiment in the early 1930’s cally shown in Fig. 1. A point source S, positronium as which aimed to support the realistic interpretation of Popper suggests, is placed at the center of the experimen- quantum mechanics and undermine the Copenhagen or- tal arrangement from which entangled pairs of particles thodoxy [1]. What Popper intends to show in his thought 1 and 2 are emitted in opposite directions along the re- experiment is that a particle can have both precise posi- spective positive and negative x-axes towards two screens tion and momentum at the same time through the corre- A and B. There are slits on both screens parallel to the lation measurement of an entangled two-particle system. y-axis and the slits may be adjusted by varying their This bears striking similarity to what EPR gedanken- widths ∆y. Beyond the slits on each side stand an array experiment of 1935 seeks to conclude [2]. But different of Geiger counters for the coincidence measurements of the particle pairs as shown in the figure. The entangled pair could be emitted to any direction in 4π solid angles from the point source. However, if particle 1 is detected ∗Email: [email protected] in a certain direction then particle 2 is known to be in the †Email: [email protected] opposite direction due to the momentum conservation of the quantum pair. 1 First, let us imagine the case in which slits A and B are width of its “diffraction pattern” at a certain distance adjusted both very narrowly. In this circumstance, coun- from “screen” B. This is obtained by recording coinci- ters should come into play which are higher up and lower dences between detectors D1 and D2 while scanning de- down as viewed from the slits. The firing of these coun- tector D2 along its y-axis which is behind “screen” B at a ters is indicative of the greater ∆py due to the smaller ∆y certain distance. Instead of a battery of Geiger counters, for each particle. There seems to be no disagreement in in our experiment only two photon counting detectors D1 this situation between both the Copenhagen school and and D2 placed behind the respective slits A and B are Popper and both sides can provide a reasonable explana- used for the coincidence detection. Both D1 and D2 are tion according to their own philosophical beliefs. driven by step motors and so can be scanned along their Next, suppose we keep the slit at A very narrow and y-axes. ∆y∆py of “photon 2” is then readily calculated leave the slit at B wide open. The main purpose of and compared with h [6]. the narrow slit A is to provide the precise knowledge The use of a “point source” in the original proposal has of the position y of particle 1 and this subsequently de- been much criticized and considered as the fundamen- termines the precise position of its twin (particle 2) on tal mistake Popper made [7] [8]. The major objection is side B through quantum entanglement. Now, asks Pop- that a point source can never produce a pair of entangled per, in the absence of the physical interaction with an particles which preserves two-particle momentum conser- actual slit, does particle 2 experience a greater uncer- vation. However, notice that a “point source” is not a tainty in ∆py due to the precise knowledge of its position? necessary requirement for Popper’s experiment. What is Based on his “statistical-scatter” theory, Popper provides required is the position entanglement of the two-particle a straightforward prediction: particle 2 must not experi- system: if the position of particle 1 is precisely known, ence a greater ∆py unless a real physical narrow slit B is the position of particle 2 is also 100% determined. So applied. However, if Popper’s conjecture is correct, this one can learn the precise knowledge of a particle’s posi- would imply the product of ∆y and ∆py of particle 2 tion through quantum entanglement. Quantum mechan- could be smaller than h (∆y∆py <h). This may pose a ics does allow the position entanglement for an entangled serious difficulty for the Copenhagen camp and perhaps system (EPR state) and there are certain practical mech- for many of us. On the other hand, if particle 2 going anisms, such as that the “ghost-image” effect shown in to the right does scatter like its twin which has passed our experiment, that can be used for its realization. though slit A, even though slit B is wide open, we are The schematic experimental setup is shown in Fig.4 then confronted with an apparent action-at-a-distance! with detailed indications of the various distances. A CW Argon ion laser line of λp = 351:1nm is used to pump a 3mm long beta barium borate (BBO) crystal III. REALIZATION OF POPPER'S EXPERIMENT for type-II SPDC [10] to generate an orthogonally polar- ized signal-idler photon pair. The laser beam is about We have realized Popper’s experiment with the use of 3mm in diameter with a diffraction limited divergence. the entangled two-photon source of spontaneous para- It is important not to focus the pump beam so that the metric down conversion (SPDC) [3] [4]. In order to phase-matching condition, ks + ki = kp, is well rein- clearly demonstrate all aspects of the historical and mod- forced in the SPDC process [4], where kj (j = s; i; p) ern experimental concerns in a practical manner, Pop- is the wavevectors of the signal (s), idler (i), and pump per’s original design is slightly modified as shown in (p) respectively. The collinear signal-idler beams, with Fig. 2. The two-photon source is a CW Argon ion λs = λi = 702:2nm =2λp are separated from the pump laser pumped SPDC which provides a two-photon entan- beam by a fused quartz dispersion prism, and then split gled state that preserves momentum conservation for the by a polarization beam splitter PBS. The signal beam signal-idler photon pair in the SPDC process. By taking (“photon 1”) passes through the converging lens LS with advantage of the nature of entanglement of the signal- a 500mm focal length and a 25mm diameter. A 0:16mm idler pair (also labeled “photon 1” and “photon 2”) one slit is placed at location A which is 1000mm (= 2f)be- could make a “ghost image” of slit A at “screen” B, see hind the lens LS.
Load more

Recommended publications
  • 1 Hilary Putnam, Reason, Truth and History, (Cambridge: Harvard University Press, 1979). Henceforth 'RTH'. the Position Th
    [The Journal of Philosophical Research XVII (1992): 313-345] Brains in a Vat, Subjectivity, and the Causal Theory of Reference Kirk Ludwig Department of Philosophy University of Florida Gainesville, FL 32611-8545 1. Introduction In the first chapter of Reason, Truth and History,1 Putnam argued that it is not epistemically possible that we are brains in a vat (of a certain sort). If his argument is correct, and can be extended in certain ways, then it seems that we can lay to rest the traditional skeptical worry that most or all of our beliefs about the external world are false. Putnam’s argument has two parts. The first is an argument for a theory of reference2 according to which we cannot refer to an object or a type of object unless we have had a certain sort of causal interaction with it. The second part argues from this theory to the conclusion that we can know that we are not brains in a vat. In this paper I will argue that Putnam’s argument to show that we cannot be brains in a vat is unsuccessful. However, the flaw is not in the argument from the theory of reference to the conclusion 1 Hilary Putnam, Reason, Truth and History, (Cambridge: Harvard University Press, 1979). Henceforth ‘RTH’. The position that Putnam advances in this first chapter is one that in later chapters of RTH he abandons in favor of the position that he calls ‘internal realism’. He represents the arguments he gives in chapter 1 as a problem posed for the ‘external realist’, who assumes the possibility of a God’s eye point of view.
    [Show full text]
  • Meaning Ain't in the Head 1. Hilary Putnam (1926-2016)
    Louis deRosset { Spring 2019 Putnam: Meaning Ain't in the Head 1. Hilary Putnam (1926-2016): Philosopher, logician, mathematician. Putnam is famous for important and seminal work in just about every sub- field in philosophy. 2. Putnam's Target: . two unchallenged assumptions: (1) That knowing the meaning of a term is just a matter of being in a certain psychological state. (2) That the meaning of a term determines its extension. (700) DEFINITION: The extension of a term is its nominatum: • for names, definite descriptions: a certain person, place, or thing. EX.: `Obama', `The president of the U.S.' • for predicates: the set of things of which the predicate is true. EX.: `is a student', `is a person'. Putnam's Target is the Fregean theory of intentionality: The Fregean Triangle (yet again!): Sense 4< expresses determines #+ expression Nominatum Putnam (following Carnap) uses different terminology for the same ideas: Frege says... Putnam says... sense meaning, intension nominatum extension The Fregean Triangle (Putnam's terms): meaning 3; expresses determines expression extension"* Putnam adds the speaker to the picture [BLACKBOARD: draw the speaker with a speech balloon around the expression]. Louis deRosset { Spring 2019 In this situation, Putnam (following Frege), says that the speaker grasps the sense. [BLACKBOARD: draw the grasping relation between the speaker and the sense]. Putnam's target: (a) grasping a meaning is a psychological state; and (b) meaning determines extension, (i.e. if A and B grasp the same meaning, their expressions have the same extension.) 3. Putnam's Thesis: I shall argue that these two assumptions are not jointly sat- isfied by any notion, let alone any notion of meaning.
    [Show full text]
  • A Historical Survey of Sir Karl Popper's Contribution to Quantum
    A Historical Survey of Sir Karl Popper’s Contribution to Quantum Mechanics William M. Shields Worcester Polytechnic Institute, Worcester, Massachusetts, United States. E-mail: [email protected] Editors: Ion C. Baianu, Christoph Lehner, Debajyoti Gangopadhyay & Danko Georgiev Article history: Submitted on May 28, 2012; Accepted on July 28, 2012; Published on November 15, 2012. ir Karl Popper (1902–1994), though not 1 Popper in the physics journals trained as a physicist and embarrassed early Sin his career by a physics error pointed out by Sir Karl Popper, by any measure one of the preeminent Einstein and Bohr, ultimately made substantial con- philosophers of the twentieth century, died in 1994 at the tributions to the interpretation of quantum mechan- age of 92. He was productive to the end, publishing in ics. As was often the case, Popper initially formu- the year of his death a criticism of Kuhn’s incommensu- lated his position by criticizing the views of others – rability of paradigms [1]. That debate continues over his in this case Niels Bohr and Werner Heisenberg. Un- many and profound philosophical ideas and opinions is derlying Popper’s criticism was his belief that, first, hardly surprising, almost two decades after his death. The the Copenhagen interpretation of quantum mechan- proliferation of book-length biographies and scholarly ics abandoned scientific realism and second, the as- philosophical articles is testimony to Popper’s standing as sertion that quantum theory was complete (an asser- a philosopher [2–5]. Major conferences are also regularly tion rejected by Einstein among others) amounted held on the thought of Karl Popper [6, 7].
    [Show full text]
  • Hilary Putnam: Mind, Meaning and Reality
    Hilary Putnam: On Mind, Meaning and Reality Interview by Josh Harlan HRP: What are the ultimate goals of the philosophy of mind? What distinguishes the philosophy of mind from such fields as neuroscience, cognitive science, and psychology? Putnam: Like all branches of philosophy, philosophy of mind is the dis- cussion of a loose cluster of problems, to which problems get added (and sometimes subtracted) in the course of time. To make things more com- plicated, the notion of the "mind" is itself one which has changed a great deal through the millenia. Aristotle, for example, has no notion which exactly corresponds to our notion of "mind". The psyche, or soul, in Aristotle's philosophy is not the same as our "mind" because its functions include such "non-mental" functions as digestion and reproduction. (This is so because the "sou1"'is simply the form of the organized living body in Aristotle's philosophy. Is this obviously a worse notion than our present- day notion of "mind"?) And the nous, or reason, in Aristotle's philosophy, excludes many functions which we regard as mental (some of which are taken over by the thumos, the integrative center which Aristotle locates in the heart). Even in my lifetime I have seen two very different ways of conceiving the mind: one, which descended from British empiricism, conceived of the mental as primarily composed of sensations. "Are sensations (or qualia, as philosophers sometimes say) identical with brain processes?" was the "mind-body problem" for this tradition. (The mind conceived of as a "bundle of sensations" might be called "the English mind".) The other way conceived of the mind as primarily characterized by reason and inten- tionality - by the ability to judge, and to refer.
    [Show full text]
  • MURPHY, Alice. Thought Experiments and the Scientific Imagination. Phd
    i Thought Experiments and the Scientific Imagination Alice Murphy Submitted in accordance with the requirements for the degree of Doctor of Philosophy The University of Leeds School of Philosophy, Religion, and History of Science September 2020 ii The candidate confirms that the work submitted is her own and that appropriate credit has been given where reference has been made to the work of others. This copy has been supplied on the understanding that it is copyright material and that no quotation from the thesis may be published without proper acknowledgement. The right of Alice Murphy to be identified as Author of this work has been asserted by her in accordance with the Copyright, Designs and Patents Act 1988. © 2020 The University of Leeds and Alice Murphy iii Acknowledgements Firstly, a huge thank you to my supervisors, Steven French and Aaron Meskin. It’s hard to do justice to the support and insights that you have each provided over the past four years. Steven has been endlessly generous, and has an open minded approach to research that is a constant source of inspiration. Aaron’s meticulous attention to detail has made me a more careful writer and thinker. You’ve both enabled me to form sketchy ideas into arguments, spurred me on when I’ve been lacking in confidence, and have made the whole process energising and, dare I say it, fun. At the risk of causing too high of expectations of the thesis that follows, I also want to say thank you to Milena Ivanova, Andrea Blomqvist, Mike Stuart, Max Jones, Fiora Salis, Karim Thébault and Adrian Currie for incredibly valuable conversations and feedback.
    [Show full text]
  • Philosophical Imagination
    Philosophical Imagination Philosophical Imagination: Thought Experiments and Arguments in Antiquity Edited by Boris Vezjak Philosophical Imagination: Thought Experiments and Arguments in Antiquity Edited by Boris Vezjak This book first published 2021 Cambridge Scholars Publishing Lady Stephenson Library, Newcastle upon Tyne, NE6 2PA, UK British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Copyright © 2021 by Boris Vezjak and contributors All rights for this book reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owner. ISBN (10): 1-5275-6975-6 ISBN (13): 978-1-5275-6975-1 TABLE OF CONTENTS Preface ...................................................................................................... vii List of Contributors ................................................................................... xi Part 1: Thought Experiments from Plato to Hume Chapter One ................................................................................................ 3 The Anatomy of Three Thought Experiments in Plato’s Republic, Apology, and in Alcibiades Minor Andre M. Archie Chapter Two ............................................................................................. 25 From Kallipolis to Utopia: The Metamorphoses of Ideal Theory Nenad Miščević Chapter Three ..........................................................................................
    [Show full text]
  • Fiction As Thought Experiment
    Fiction as Thought Experiment Catherine Z. Elgin Harvard University Although ªctions and thought experiments are not physical realizations of the phenomena they pertain to, like real experiments, they exemplify properties or patterns that they share with those phenomena. They thereby afford epistemic access to properties and patterns that are realized in fact. The Problem Jonathan Bennett (1974) maintains that Huckleberry Finn’s deliberations about whether to return Jim to slavery afford insight into the tension be- tween sympathy and moral judgment; Miranda Fricker (2007) argues that the trial scene in To Kill a Mockingbird affords insight into the nature of testimonial injustice. Neither claims merely that the works prompt an at- tentive reader to think something new or to change her mind. Rather, they consider the reader cognitively better off for her encounters with the novels. Nor is her cognitive improvement restricted to acquiring new justiªed true beliefs about the works themselves. What the reader gleans is supposed to enhance her knowledge or understanding of the extra- literary world. Fricker and Bennett are probably right. But their being right raises an epistemological problem. How can a work of ªction which is not and is known not to be true provide any measure of epistemic access to the way things actually are? Is it really possible to ªnd out about the world by making things up? One attractive answer is that works of ªction are thought experiments. Like literary ªctions, thought experiments neither are nor purport to be physically realized. Nevertheless, they evidently enhance understanding of the phenomena they pertain to.
    [Show full text]
  • Nozick (1974, 1989)
    The Experience Machine by Robert Nozick (1974, 1989) Excerpt from Anarchy, State, and Utopia (1974) What matters other than how people's experiences feel "from the inside"? Suppose there were an experience machine that would Give you any experience that you desired. Superduper neuropsycholoGists could stimulate your brain so that you would think and feel you were writinG a Great novel, or makinG a friend, or readinG an interestinG book. All the time you would be floatinG in a tank, with electrodes attached to your brain. Should you pluG into this machine for life, preproGramminG your life's experiences? If you are worried about missinG out on desirable experiences, we can suppose that business enterprises have researched thorouGhly the lives of many others. You can pick and choose from their large library or smorgasbord of such experiences, selectinG your life's experiences for, say, the next two years. After two years have passed, you will have ten minutes or ten hours out of the tank, to select the experiences of your next two years. Of course, while in the tank you won't know that you're there; you'll think it's all actually happeninG. Others can also pluG in to have the experiences they want, so there's no need to stay unpluGGed to serve them. (IGnore problems such as who will service the machines if everyone pluGs in.) Would you pluG in? What else can matter to us, other than how our lives feel from the inside? Nor should you refrain because of the few moments of distress between the moment you've decided and the moment you're pluGGed.
    [Show full text]
  • Hume's Missing Shade of Blue Reexamined
    City University of New York (CUNY) CUNY Academic Works Student Theses Baruch College 1-1-2014 Hume's Missing Shade of Blue reexamined Vyacheslav Faylayev Baruch College How does access to this work benefit ou?y Let us know! More information about this work at: https://academicworks.cuny.edu/bb_etds/18 Discover additional works at: https://academicworks.cuny.edu This work is made publicly available by the City University of New York (CUNY). Contact: [email protected] Hume’s Missing Shade of Blue Reexamined By Vyacheslav Faylayev Submitted to the Committee of Undergraduate Honors at Baruch College of the City University of New York on May 5th, 2014 in partial fulfillment of the requirements for the degree of Bachelor of Arts in Philosophy with Honors. ___________________________ Professor Thomas Teufel Faculty Supervisor ___________________________ ___________________________ Professor Douglas Lackey Professor Charlotte Brooks Page | 1 HUME’S MISSING SHADE OF BLUE REEXAMINED By Vyacheslav Faylayev Table of Contents I. Introduction……………………………………………………….........................2 II. Breaking Down the Missing Shade of Blue……………………………………....6 III. The Missing Shade of Blue: Exception, Not a Threat…………………………....9 IV. Hume’s Copy Principle & Causality………………………………………...…..15 V. Hume’s Self-Criticism………………………………………………...……...…17 VI. Possible Arguments against Hume’s Missing Shade of Blue Defused……….....20 VII. Conclusion………………………………………………...………………….…31 VIII. References………………………………………………………………………34 Page | 2 Hume’s Missing Shade of Blue Reexamined Abstract David Hume, known as a strict empiricist, posits that all perceptions are divided into impressions and ideas. Except for a lower degree of vivacity, ideas directly resemble their corresponding impressions. This is the core of Hume’s ‘copy principle,’ which claims that all ideas are simply copies of their corresponding more lively impressions.
    [Show full text]
  • Notes on Leibniz Thought Experiment
    Notes on Leibniz thought experiment Markos Maniatis Departamento de Ciencias B´asicas, Universidad del B´ıo-B´ıo Avda. Andr´es Bello s/n, Casilla 447 Chill´an, Chile email: [email protected] Leibniz thought experiment of perception, sensing, and thinking is reconsidered. We try to understand Leibniz picture in view of our knowledge of basic neuroscience. In particular we can see how the emergence of consciousness could in principle be understood. Gottfried Wilhelm Leibniz, Monadology (1714), §17 [1]: “Besides, it must be admitted that perception, and anything that depends on it, cannot be explained in terms of mechanistic causation – that is, in terms of shapes and motions. Let us pretend that there was a machine, which was constructed in such a way as to give rise to thinking, sensing, and having perceptions. You could imagine it expanded in size (while retaining the same proportions), so that you could go inside it, like going into a mill. On this assumption, your tour inside it would show you the working parts pushing each other, but never anything which would explain a perception. So perception is to be sought, not in compounds (or machines), but in simple substances. Furthermore, there is nothing to be arXiv:1309.0846v1 [q-bio.NC] 3 Sep 2013 found in simple substances, apart from perceptions and their changes. Again, all the internal actions of simple substances can consist in nothing other than perceptions and their changes.” We would like to reconsider Leibniz thought experiment, presented about three centuries ago. Today we know, that at a tour inside the elementary working parts are the neurons, which push each other by means of electrical activity.
    [Show full text]
  • The Cognitive Value of Fiction: Two Models
    teorema Vol. XXXV/3, 2016, pp. 149-164 ISSN: 0210-1602 [BIBLID 0210-1602 (2016) 35:3; pp. 149-164] The Cognitive Value of Fiction: Two Models Frank Boardman RESUMEN Un buen número de controversias actuales incluyen cuestiones sobre el valor cog- nitivo de la ficción. En cada uno de esos contextos encontramos un cierto escepticismo sobre lo que podría llamarse la “tesis fuerte”: que podemos alcanzar determinado cono- cimiento proposicional no-trivial a partir de la ficción en virtud del contenido narrativo de esta. Presento dos maneras en las que las ficciones pueden proporcionarnos (y a menudo lo proporcionan de forma efectiva) conocimiento proposicional precisamente de ese modo. Defiendo que esos modelos ayudar a dar una respuesta a gran parte del escepticismo que se ha mencionado. Concluyo considerando algunas implicaciones de todo el proyecto y algunas objeciones al mismo. PALABRAS CLAVE: valor cognitivo de la ficción, aprender de la ficción, Aristóteles. ABSTRACT A number of current controversies involve questions about the cognitive value of fiction. In each of these contexts, we find skepticism about what might be called the “strong thesis,” that we can non-trivially gain determinate propositional knowledge from fictions by virtue of their narrative contents. I offer two ways in which fictions can (and often do) provide us with propositional knowledge in just this way. I make the case that these models help answer much of the skepticism mentioned above. I conclude by considering a number of implications of and objections to the entire project. KEYWORDS: Cognitive Value of Fiction, Learning from Fiction, Aristotle. A number of recent and current controversies involve questions about the cognitive value of fiction.
    [Show full text]
  • Article Evaluating the Cognitive Success of Thought Experiments
    Evaluating the Cognitive Success of Thought Experiments Damián Islas Mondragón Transversal: International Journal for the Historiography of Science, 3 (2017) 68-76 ISSN 2526-2270 www.historiographyofscience.org © The Author 2017 – This is an open access article Article Evaluating the Cognitive Success of Thought Experiments Damián Islas Mondragón1 Abstract: Thought experiments are widely used in natural science research. Nonetheless, their reliabil- ity to produce cognitive results has been a disputable matter. This study is conducted to pre- sent some rules of confirmation for evaluating the cognitive outcome of thought experi- ments. I begin given an example of a “paradigmatic” thought experiment from Galileo Galilei: the falling bodies. Afterwards, I briefly surveying two different accounts of thought experi- ments: James R. Brown’s rationalism and John D. Norton’s empiricism. Then, I discuss their positions and I show that none of them may tip the balance towards the rationalism or em- piricism they try to defend. Finally, I put forward that the notion of confirmation, connected to the notion of increasing plausibility, can be used to develop some confirmation rules to compare the explanatory power of thought experiments in competition, regardless of their 68 rational or empirical nature in which the discussion of this type of experiment has been en- gaged in recent years. Keywords: Thought Experiments; Back Ground knowledge; Confirmation; Plausibility; Success Received: 05 August 2017. Reviewed 31 October 2017. Accepted: 30 November 2017. DOI: http://dx.doi.org/10.24117/2526-2270.2017.i3.06 _____________________________________________________________________________ Introduction Thought experiments are “unexecuted experiments” devised to support or refute a scientific theory – or part of it.
    [Show full text]