The Joy of Science

Jim Al-Khalili has distilled the very essence of science. This book is packed full of joy, inspiration, and real wisdom.

Alice Roberts, Professor of Public Engagement in Science, University of Birmingham

Jim Al-Khalili eloquently reminds us of all the reasons to celebrate science. A lovely little book that will serve you well as a trusted guide in this troubled post-truth era.

Sabine Hossenfelder, physicist and author of Lost in Math

"The Joy of Science pulls back the curtain on the essential nature of science and tackles the confusions the public confronts in understanding how it’s done. I highly recommend Al-Khalili’s book to anyone, scientist or not, interested in thinking more scientifically."

S. James Gates Jr., coauthor of Proving Einstein Right

"In the age of post-truth politics, when misinformation and conspiracy theories flood social media and endanger lives, Al-Khalili’s book is a patient, gentle, and humane corrective. The Joy of Science is a call for a more rational and discerning attitude to what we experience in our lives, guided by respect for expertise and critical judgement but also by compassion."

Philip Ball, author of Beyond Weird and Curiosity

Jim Al-Khalili is justly celebrated as a leading expositor of science. In this book, he distills the nature and limits of our scientific knowledge and highlights how the scientific mindset can help us in everyday life. His wise precepts are especially welcome at a time when, despite science’s triumphs, public discourse is bedeviled more than ever by fake news and conspiracy theories. We’d all be better citizens if we took his message to heart—this book deserves wide readership.

Martin Rees, author of On the Future

Science is a way of thinking about and understanding the world—and in this captivating book, Al-Khalili argues that we all should be thinking more scientifically. Writing exquisitely about the complexities of scientific concepts and ideas, he uncovers our biases and dispels common myths and misunderstandings about how the world and science works. His highly entertaining book is crucial reading for all of us, especially at this time of global pandemic and climate crisis, when finding solutions depends critically on a deeper understanding of what science is and isn’t.

Sarah-Jayne Blakemore, author of Inventing Ourselves

This is a beautiful, straightforward, and readable little book with so much to say about how and why we do science. I recommend it to anyone in these crazy times who wants to understand the meaning and value of following the science.

Daniel M. Altmann, Imperial College London

This pithy and insightful book provides readers with a collection of fun and timely ideas in an accessible way.

Sean Carroll, author of Something Deeply Hidden

"Jim Al-Khalili’s latest masterpiece beautifully conveys just how profound, intimate, and unique our connection with science is. The Joy of Science awakens the scientific thinking that is deeply rooted in all of us, revealing not only what its methods truly are but also how one can find enlightenment by trying them out."

Claudia de Rham, Imperial College London

Al-Khalili’s timely and inspirational writing allows us all to experience a touch of the ‘joy’ of science.

Helen Pearson, Chief Magazine Editor of Nature

THE JOY OF SCIENCE

THE JOY OF SCIENCE

JIM AL-KHALILI

PRINCETON UNIVERSITY PRESS

PRINCETON AND OXFORD

Copyright © 2022 by Jim Al-Khalili

Princeton University Press is committed to the protection of copyright and the intellectual property our authors entrust to us. Copyright promotes the progress and integrity of knowledge. Thank you for supporting free speech and the global exchange of ideas by purchasing an authorized edition of this book. If you wish to reproduce or distribute any part of it in any form, please obtain permission.

Requests for permission to reproduce material from this work should be sent to [email protected]

Published by Princeton University Press

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All Rights Reserved

Library of Congress Cataloging-in-Publication Data

Names: Al-Khalili, Jim, 1962- author.

Title: The joy of science / Jim Al-Khalili.

Description: Princeton : Princeton University Press, [2022] | Includes bibliographical references and index.

Identifiers: LCCN 2021029263 (print) | LCCN 2021029264 (ebook) | ISBN 9780691211572 (hardback) | ISBN 9780691235660 (ebook)

Subjects: LCSH: Science—Philosophy.

Classification: LCC Q175 .A485 2022 (print) | LCC Q175 (ebook) | DDC 501—dc23

LC record available at https://lccn.loc.gov/2021029263

LC ebook record available at https://lccn.loc.gov/2021029264

Version 1.0

British Library Cataloging-in-Publication Data is available

Editorial: Ingrid Gnerlich and Whitney Rauenhorst

Production Editorial: Mark Bellis

Text and Cover Design: Chris Ferrante

Production: Jacquie Poirier

Publicity: Sara Henning-Stout and Kate Farquhar-Thomson

Copyeditor: Annie Gottlieb

For my father

CONTENTS

Prefaceix

Introduction1

1   Something is either true, or it isn’t30

2   It’s more complicated than that51

3   Mysteries are to be embraced, but also to be solved65

4   If you don’t understand something, it doesn’t mean you can’t if you try80

5   Don’t value opinion over evidence97

6   Recognize your own biases before judging the views of others114

7   Don’t be afraid to change your mind130

8   Stand up for reality141

Conclusion155

Glossary163

Bibliography179

Further Reading189

Index191

PREFACE

As a young student in the mid-1980s, I read a book called To Acknowledge the Wonder by the English physicist Euan Squires. It was about the latest ideas in fundamental physics (at the time), and I still have it somewhere on my shelf nearly four decades later. While some of the material in that book is now outdated, I have always liked its title. At a time when I was contemplating a career in physics, the chance to ‘acknowledge the wonders’ of the physical world was what really inspired me to devote my life to science.

There are many reasons why people pursue their interests in one subject or another. In science, some enjoy the thrill of climbing into the crater of a volcano or crouching on a cliff’s edge to observe birds nesting—or looking through telescopes or microscopes to see worlds beyond our senses. Some design ingenious experiments on their laboratory workbenches to reveal the secrets inside stars, or build giant underground particle accelerators to probe the building blocks of matter. Some study the genetics of microbes so they can develop drugs and vaccines to protect us against them. Others become fluent in mathematics and scrawl pages upon pages of abstract but beautiful algebraic equations, or write thousands of lines of code that instruct their supercomputers to simulate Earth’s weather or the evolution of galaxies, or even model the biological processes inside our bodies. Science is a vast enterprise, and there is inspiration, passion, and wonder everywhere you look.

But the old adage that beauty is in the eye of the beholder applies to science as well as more generally in our lives. What we regard as fascinating or beautiful is highly subjective. Scientists know as well as anyone that new subjects and new ways of thinking can be daunting. When you haven’t been properly introduced to a subject, it can seem downright forbidding. However, my response would be that, if we try, we can almost always gain a better understanding of an idea or concept that might once have seemed unfathomable to us. We just have to keep our eyes and minds open and take the time we need to think things through and absorb the information—not necessarily to the level of experts, but just enough to comprehend what we need.

Let’s take as an example a simple and common phenomenon in the natural world: the rainbow.¹ We can all agree that there is something enchanting about rainbows. Is their magic diminished if I explain to you the science of how they form? The poet Keats claimed that Newton had destroyed all the poetry of the rainbow, by reducing it to the prismatic colours. In my view, far from ‘destroying its poetry,’ science only enhances our appreciation of nature’s beauty. See what you think.

Rainbows combine two ingredients: sunshine and rain. But the science behind the way in which they combine to create the arc of colour we see in the misty sky is as beautiful as the sight itself. Rainbows are made of broken sunlight that reaches our eyes after the Sun’s rays strike a billion raindrops. As the Sun’s rays enter each water droplet, all the different colours of light that make up sunlight slow down slightly to travel at different speeds, bending and separating out from each other in a process called refraction.² They then bounce off the backs of the droplets, returning to pass through their fronts at different points, refracting a second time as they do so and fanning out into the colours of the rainbow. If we measure the angles between the sunbeam and the different-coloured rays that emerge from the veil of raindrops in front of us—we find that they range from 40 degrees for violet light, which undergoes the most refraction and so forms the innermost colour of the rainbow, to 42 degrees for red light, which undergoes the least and forms the outer rim of the rainbow (see the diagram).³

Even more wondrously, this arc of splintered sunlight is really just the top part of a circle—the curved surface of an imaginary cone lying on its side, whose tip is located in our eyes. And because we are standing on the ground, we only see the top half of the cone. But, if we were able to float up into the sky, we would see the entire rainbow as a complete circle.

You cannot touch a rainbow. It has no substance; it does not exist in any particular part of the sky. A rainbow is an intangible interaction between the natural world and our eyes and brains. In fact, no two people see the same rainbow. The one we see is made from those rays of light that have entered our eyes alone. So, each of us experiences his or her own unique rainbow, created by nature for us and us alone. This, for me, is what a scientific understanding can give us: a richer, more profound—and more personal—appreciation of the world; one we would never had had without science.

DIAGRAM OF A RAINBOW

Rainbows are so much more than just a pretty arc of colour, just as science is so much more than hard facts and lessons in critical thinking. Science helps us see the world more deeply, enriches us, enlightens us. My hope is that this book will welcome you to a world of light and colour, truth and profound beauty—a world that will never fade as long as we all keep our eyes and minds open and share what we know with each other. The closer we look, the more we can see and the more we can wonder. I hope you will join me in acknowledging the wonder—the joy of science.

1 In beginning this book by invoking