Science as a candle in the dark

THE DEMON-HAUNTED WORLD Carl Sagan is the David Duncan Professor of Astronomy and Space Sciences and Director of the Laboratory for Planetary Studies at Cornell University; Distinguished Visiting Scientist at the Jet Propulsion Laboratory, California Institute of Technology; and co-founder and President of The Planetary Society, the largest spaceinterest group in the world. For his work, DrSagan has been awarded the NASA Medals for Exceptional Scientific Achievement and (twice) for Distinguished Public Service, as well as the NASA Apollo Achievement Award. Asteroid 2709 Sagan is named after him.

This is the twenty-ninth book Carl Sagan has authored, co-authored or edited. Some of his other books: Intelligent Life in the Universe

(with I. S. Shklovskii)
The Dragons of EdenBroca's Brain Cosmos Contact: A Novel Comet

(with Ann Druyan)
A Path Where No Man Thought: Nuclear Winter and the End of the Arms Race

(with Richard Turco)
Shadows of Forgotten Ancestors: A Search for Who We Are

(with Ann Druyan)
Pale Blue Dot: A Vision of the Human Future in Space

The Demon-Haunted World
Science as a Candle in the Dark

Carl Sagan

HEADLINE

Copyright © 1997Carl Sagan The right of Carl Sagan to be identified as the Author of the Work has been asserted by him in accordance with the Copyright, Designs and Patents Act 1988. First published in 1996 by HEADLINE BOOK PUBLISHING First published in this edition in 1997 by HEADLINE BOOK PUBLISHING 10 9 8 7 6 5 4 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, ortransmitted, in any form or by any means without the prior written permission of the publisher, nor be otherwise circulated in any form of binding or cover other than that in which it is published and without a similar condition being imposed on the subsequent purchaser. ISBN 0 7472 5156 8 Typeset by Letterpart Limited, Reigate, Surrey Printed and bound in Great Britain by Clays Ltd, St Ives plcHEADLINE BOOK PUBLISHING A division of Hodder Headline PLC 338 Euston Road London NW1 3BH

To Tonio, My grandson. I wish you a world Free of demons And full of light.

We wait for light, but behold darkness. Isaiah 59:9

It is better to light one candle than to curse the darkness. Adage

Contents

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Preface: My TeachersThe Most Precious Thing Science and Hope The Man in the Moon and the Face on Mars Aliens Spoofing and Secrecy Hallucinations The Demon-Haunted World On the Distinction between True and False Visions Therapy The Dragon in My Garage The City of Grief The Fine Art of Baloney Detection Obsessed with Reality Antiscience Newton's Sleep When Scientists Know Sin The Marriage of Scepticism and Wonder TheWind Makes Dust No Such Thing as a Dumb Question House on Fire* The Path to Freedom* Significance Junkies Maxwell and The Nerds

1 6 27 43 61 77 93 108 129 143 160 179 189 207 234 253 267 277 290 300 318 333 345 355

24 25

Science and Witchcraft* Real Patriots Ask Questions* Acknowledgements References Index * Written with Ann Druyan

377 396 409 412 427

Preface My Teachers

I

twas a blustery fall day in 1939. In the streets outside the apartment building, fallen leaves were swirling in little whirlwinds, each with a life of its own. It was good to be inside and warm and safe, with my mother preparing dinner in the next room. In our apartment there were no older kids who picked on you for no reason. Just the week before, I had been in a fight - I can't remember, after allthese years, who it was with; maybe it was Snoony Agata from the third floor - and, after a wild swing, I found I had put my fist through the plate glass window of Schechter's drug store. Mr Schechter was solicitous: 'It's all right, I'm insured,' he said as he put some unbelievably painful antiseptic on my wrist. My mother took me to the doctor whose office was on the ground floor of our...