Anthropic Bias: Observation Selection Effects in Science and Philosophy (Studies in Philosophy)

242 Pages·2002·1.26 MB·English

by  Nick Bostrom

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S P
TUDIES IN HILOSOPHY
OUTSTANDING DISSERTATIONS
Edited by
Robert Nozick
Pellegrino University Professor
at Harvard University
A ROUTLEDGE SERIES
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S P
TUDIES IN HILOSOPHY
ROBERT NOZICK,General Editor
INTUITIONAS EVIDENCE NEWTHOUGHTSABOUT OLDTHINGS
Joel Pust Krista Lawlor
TELEOLOGYANDTHE NORMS ESSAYS ON SYMMETRY
OF NATURE Jennan Ismael
William J.Fitzpatrick
DESCARTE’S METAPHYSICAL
PROBLEMS OF COMPOSITIONALITY REASONING
Zoltán Gendler Szabó Roger Florka
LOGICAND LANGUAGE IN ESSAYS ON LINGUISTIC CONTEXT
WITTGENSTEIN’S TRACTATUS SENSITIVITYAND ITS PHILOSOPHICAL
Ian Proops SIGNIFICANCE
Steven Gross
THOUGHT EXPERIMENT
On the Powers and Limits of NAMESAND NATURE IN PLATO’S
Imaginary Cases CRATYLUS
Tamar Szabó Gendler Rachel Barney
BETWEEN DEFLATIONISMAND BEAUTYAND IMPENATRABILITY IN
CORRESPONDENCETHEORY KANT’S PHILOSOPHY OF NATURE
Matthew McGrath Daniel Warren
THE RELEVANCE OF FREGEANDTHE LOGIC OF SENSEAND
PHENOMENOLOGYTOTHE REFERENCE
PHILOSOPHY OF LANGUAGE Kevin C.Klement
AND MIND
Sean D.Kelly
RISK,AMBIGUITYAND DECISION
Daniel Ellsberg
THE EXPLANATIONIST DEFENSE OF
SCIENTIFIC REALISM
Dorit A.Ganson
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A B
NTHROPIC IAS
Observation Selection Effects in Science
and Philosophy
Nick Bostrom
Routledge
New York & London
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Published in 2002 by
Routledge
29 West 35th Street
New York,NY10001
Published in Great Britain by
Routledge
11 New Fetter Lane
London EC4P 4EE
Routledge is an imprint of the Taylor & Francis Group
Printed in the United States of America on acid-free paper.
Copyright © 2002 by Nick Bostrom
All rights reserved.No part of this book may be reprinted or reproduced or
utilized in any form or by any electronic,mechanical,or other means,now
known or hereafter invented,including photocopying and recording,or in any
information storage or retrieval system,without permission in writing from the
publisher.
10 9 8 7 6 5 4 3 2 1
Library of Congress Cataloging-in-Publication Data
Bostrom,Nick,1973–
Anthropic bias :observation selection effects in science and philosophy / by
Nick Bostrom.
p.cm.— (Studies in philosophy)
Includes bibliographical references and index.
ISBN0-415-93858-9
1.Methodology. 2.Anthropic principle. 3.Selectivity (Psychology)
4.Observation (Scientific method) I.Title. II.Studies in philosophy (New York,
N.Y.)
BD241.B657 2002
121'.6—dc21 2001058887
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This book is dedicated to my father—tack pappa!
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02 Contents (vii-x) 6/4/02 10:37 AM Page vii
Contents
ACKNOWLEDGEMENTS xi
PREFACE xiii
CHAPTER1
INTRODUCTION 1
Observation selection effects 1
A brief history of anthropic reasoning 5
Synopsis of this book 7
CHAPTER2
FINE-TUNING IN COSMOLOGY 11
Does fine-tuning need explaining? 13
No “Inverse Gambler’s Fallacy” 16
Roger White and Phil Dowe’s analysis 18
Surprising vs. unsurprising improbable events 23
Modeling observation selection effects: the angel parable 32
Preliminary conclusions 39
CHAPTER3
ANTHROPIC PRINCIPLES: THE MOTLEY FAMILY 43
The anthropic principle as expressing an observation
selection effect 43
Anthropic hodgepodge 46
Freak observers and why earlier formulations are inadequate 51
The Self-Sampling Assumption 57
vii
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viii Contents
CHAPTER4
THOUGHT EXPERIMENTS SUPPORTING THE
SELF-SAMPLING ASSUMPTION 59
The Dungeon gedanken 59
Two thought experiments by John Leslie 62
The Incubatorgedanken 64
The reference class problem 69
CHAPTER5
THE SELF-SAMPLING ASSUMPTION IN SCIENCE 73
SSA in cosmology 73
SSA in thermodynamics 76
SSA in evolutionary biology 78
SSA in traffic analysis 82
SSA in quantum physics 84
Summary of the case for SSA 86
CHAPTER6
THE DOOMSDAY ARGUMENT 89
Background 89
Doomsayer Gott 90
The incorrectness of Gott’s argument 92
Doomsayer Leslie 94
The premisses of DA, and the Old evidence problem 96
Leslie’s views on the reference class problem 104
Alternative conclusions of DA 107
CHAPTER7
INVALID OBJECTIONS AGAINST THE DOOMSDAY ARGUMENT 109
Doesn’t the Doomsday argument fail to
“target the truth”? 109
The “baby-paradox” 111
Isn’t a sample size of one too small? 115
Couldn’t a Cro-Magnon man have used the
Doomsday argument? 116
We can make the effect go away simply by considering
a larger hypothesis space 116
Aren’t we necessarily alive now? 118
Sliding reference of “soon” and “late”? 119
How could I have been a 16th century human? 119