Advance Praise for “ You Are Not Expected to Understand This” “ In truth, ‘You Are Not Expected to Understand This’ is startlingly understandable! These vivid, lucid, brilliant essays tell the ori- gin stories of coding, the secret infrastructure that shapes our online life. We meet the people who wrote and rewrote the lines of code that changed the world. We glimpse their ambitions, mis- takes, remorse, fixes, and ingenuity. We understand why (and how) women were the ones who designed early programming languages like COBOL; how pop-up ads came to exist; how the ‘like’ button blew up news and politics as we knew them. Read this book, and you will never look at your newsfeed the same way again.” — Liza Mundy, author of Code Girls: The Untold Story of the American Women Code Breakers of World War II “C ode powers much of modern life, yet most of us spend little time thinking about it. This book will change that. Wide-ranging, provocative, and bursting with humanity, ‘You Are Not Expected to Understand This’ is essential reading on the history and culture of code.” — Sara Wachter-Boettcher, author of Technically Wrong: Sexist Apps, Biased Algorithms, and Other Threats of Toxic Tech “C ode governs our lives—and this book does a delightful job of giving us a glimpse into some of the biggest wins, and most co- lossal blunders, in software.” — Clive Thompson, author of Coders: The Making of a New Tribe and the Remaking of the World “ You Are Not Expected to Understand This” “ You Are Not Expected to Understand This” How 26 Lines of Code Changed the World Edited by Torie Bosch With an introduction by Ellen Ullman and illustrations by Kelly Chudler Princeton University Press / Princeton & Oxford Compilation and preface copyright © 2022 by Slate Magazine. Essays and illustrations copyright © 2022 by Princeton University Press. 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 41 William Street, Princeton, New Jersey 08540 99 Banbury Road, Oxford OX2 6JX press.princeton.edu All Rights Reserved Library of Congress Cataloging-in-Publication Data Names: Bosch, Torie, editor. | Chudler, Kelly S., illustrator. | Ullman, Ellen, writer of introduction. Title: You are not expected to understand this : how 26 lines of code changed the world / edited by Torie Bosch ; with an introduction by Ellen Ullman and illustrations by Kelly Chudler. Description: First edition. | Princeton : Princeton University Press, [2022] | Includes bibliographical references and index. Identifiers: LCCN 2022013091 (print) | LCCN 2022013092 (ebook) | ISBN 9780691208480 (pbk. ; acid-free paper) | ISBN 9780691230818 (e-book) Subjects: LCSH: Computer programming—Popular works. | Computer science— Social aspects—Popular works. | BISAC: COMPUTERS / Programming / General | SOCIAL SCIENCE / Technology Studies Classification: LCC QA76.6 .Y585 2022 (print) | LCC QA76.6 (ebook) | DDC 005.13—dc23/eng/20220527 LC record available at https://lccn.loc.gov/2022013091 LC ebook record available at https://lccn.loc.gov/2022013092 British Library Cataloging- in- Publication Data is available Editorial: Hallie Stebbins, Kristen Hop, and Kiran Pandey Production Editorial: Natalie Baan Text and Cover Design: Chris Ferrante Production: Danielle Amatucci and Lauren Reese Publicity: Kate Farquhar- Thomson and Sara Henning- Stout Copyeditor: Michele Rosen Page 132: Comic adapted from MonkeyUser, reproduced with permission. This book has been composed in IBM Plex Printed on acid- free paper. ∞ Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 Contents Preface ix Torie Bosch Introduction 1 Ellen Ullman 1 The First Line of Code 13 Elena Botella 2 Monte Carlo Algorithms: Random Numbers in Computing from the H-B omb to Today 19 Benjamin Pope 3 Jean Sammet and the Code That Runs the World 25 Claire L. Evans 4 Spacewar: Collaborative Coding and the Rise of Gaming Culture 31 Arthur Daemmrich 5 BASIC and the Illusion of Coding Empowerment 38 Joy Lisi Rankin 6 The First Email: The Code That Connected Us Online 44 Margaret O’Mara 7 The Police Beat Algorithm: The Code That Launched Computational Policing and Modern Racial Profiling 49 Charlton McIlwain 8 “Apollo 11, Do Bailout” 56 Ellen R. Stofan and Nick Partridge vi / COntEnts 9 The Most Famous Comment in Unix History: “You Are Not Expected to Understand This” 63 David Cassel 10 The Accidental Felon 69 Katie Hafner 11 Internet Relay Chat: From Fish- Slap to LOL 75 Susan C. Herring 12 Hyperlink: The Idea That Led to Another, and Another, and Another 81 Brian McCullough 13 JPEG: The Unsung Hero in the Digital Revolution 86 Hany Farid 14 The Viral Internet Image You’ve Never Seen 91 Lily Hay Newman 15 The Pop- Up Ad: The Code That Made the Internet Worse 96 Ethan Zuckerman 16 Wear This Code, Go to Jail 102 James Grimmelmann 17 Needles in the World’s Biggest Haystack: The Algorithm That Ranked the Internet 108 John MacCormick 18 A Failure to Interoperate: The Lost Mars Climate Orbiter 113 Charles Duan COntEnts / vii 19 The Code That Launched a Million Cat Videos 119 Lowen Liu 20 Nakamoto’s Prophecy: Bitcoin and the Revolution in Trust 124 Quinn DuPont 21 The Curse of the Awesome Button 131 Will Oremus 22 The Bug No One Was Responsible For— Until Everyone Was 139 Josephine Wolff 23 The Volkswagen Emissions Scandal: How Digital Systems Can Be Used to Cheat 145 Lee Vinsel 24 The Code That Brought a Language Online 151 Syeda Gulshan Ferdous Jana 25 Telegram: The Platform That Became “the Internet” in Iran 156 Mahsa Alimardani and Afsaneh Rigot 26 Encoding Gender 162 Meredith Broussard Acknowledgments 169 Notes 171 List of Contributors 189 Index 195