Carl Sagan - Billions and Billions: Thoughts on Life and Death at the Brink of the Millennium

BILLIONS

AND BILLIONS

Thoughts on Life and

Death at the Brink

of the Millennium

CARL SAGAN

BALLANTINE BOOKS NEW YORK

Copyright 1997 by The Estate of Carl Sagan

All rights reserved under International and Pan-American Copyright Conventions. Published in the United States by The Ballantine Publishing Group, a division of Random House, Inc., New York, and simultaneously in Canada by Random House of Canada Limited, Toronto.

http://www.randomhouse.com Library of Congress Catalog Card Number: 98-96080

ISBN: 0-345-37918-7

TO MY SISTER, CARI, ONE IN SIX BILLION

Contents

List of Illustrations .....

PART I THE POWER AND BEAUTY OF QUANTIFICATION

1. Billions and Billions

2. The Persian Chessboard

3. Monday-Night Hunters

4. The Gaze of God and the Dripping Faucet

5. Four Cosmic Questions

6. So Many Suns, So Many Worlds

PART II WHAT ARE CONSERVATIVES CONSERVING?

7. The World That Came in the Mail

8. The Environment: Where Does Prudence Lie?

x Contents 9. Croesus and Cassandra

10. A Piece of the Sky Is Missing

11. Ambush: The Warming of the World

12. Escape from Ambush

13. Religion and Science: An Alliance

PART III WHERE HEARTS AND MINDS COLLIDE

14. The Common Enemy

15. Abortion: Is It Possible to Be Both "Pro-Life"

and "Pro-Choice"? (cowritten with Ann Druyan)

16. The Rules of the Game

17. Gettysburg and Now (cowritten with Ann Druyan)

18. The Twentieth Century

19. In the Valley of the Shadow

Epilogue by Ann Druyan

Index

List of Illustrations

Photograph of Carl Sagan with Johnny Carson on the Tonight show,May 30, 1980 .....

Counting big numberssix sketches by Patrick McDonnell

The Grand Vizier's rewardthree sketches by Patrick McDonnellExponential growth in bacterial population, showing the flattening of the curveExponential growth in human population, showing the flattening of the curveRipples in water on the surface of a lake, showing the wave pattern 40 The electromagnetic wavespectrumnote the small portion that we

experience as visible light

Surface-reflectance properties of ordinary pigments in visible light ..52 Carbon dioxide concentrations inEarth's atmosphere over time ..127 Timeline of global temperaturesGreenhouse Warmingsketch by Patrick McDonnell

Nuclear Powersketch by Patrick McDonnell

xii List of Illustrations

Solar Energysketch by Patrick McDonnell

Human fetal developmentdrawings showing fetus at conception and at three weeksHuman fetal developmentdrawings showing fetus at five weeks and at sixteen weeksHuman fetal developmentdrawings showing resemblance of a human fetus to, in succession, a worm, anamphibian, a reptile, and a primate

THE POWER

AND BEAUTY OF

QUANTIFICATION

There are some... who think that the number of [grains of] sand is infinite.... There are some who, without regarding it as infinite, yet think no number has been named which is great enough.... But I will try to show you

[numbers that] exceed not only the number of the mass of sand equal to the Earth filled up ... but also that of a mass equal in magnitude to the Universe.

ARCHIMEDES (CA. 28y-2I2 B.C.),

The Sand-Reckoner

I never said it. Honest. Oh, I said there are maybe 100 billion galaxies and 10 billion trillion stars. It's hard to talk about the Cosmos without using big numbers. I said "billion" many times on the Cosmos television series, which was seen by a great many people. But I never said "billions and billions." For one thing, it's too imprecise. How many billions are "billions and billions"? A few billion? Twenty billion? A hundred billion? "Billions and billions" is pretty vague. When we reconfigured and updated the series, I checkedand sure enough, I never said it.

But Johnny Carsonon whose Tonight Show I'd appeared almost thirty times over the yearssaid it.

He'd dress up in a corduroy jacket, a turtleneck sweater, and something like a mop for a wig. He had created a rough imitation of me, a kind of Doppelganger, that went around saying "billions and billions"

on late-night television. It used to bother me a little to have some simulacrum of my persona wandering off on its own, saying things that friends and colleagues would report to me the next morning. (Despite the disguise, Carsona serious amateur astronomerwould often make my imitation talk real science.) Astonishingly, "billions and billions" stuck. People liked the sound of it. Even today, I'm stopped on the street or on an airplane or at a party and asked, a little shyly, if I wouldn't-just for themsay "billions and billions."

"You know, I didn't actually say it," I tell them.

"It's okay," they reply. "Say it anyway."

I'm told that Sherlock Holmes never said, "Elementary, my dear Watson" (at least in the Arthur Conan Doyle books); Jimmy Cagney never said, "You dirty rat"; and Humphrey Bogart never said, "Play it again, Sam." But they might as well have, because these apocrypha have firmly insinuated themselves into popular culture.

I'm still quoted as uttering this simple-minded phrase in computer magazines ("As Carl Sagan would say, it takes billions and billions of bytes"), newspaper economics primers, discussions of players' salaries in professional sports, and the like.

For a while, out of childish pique, I wouldn't utter or write the phrase, even when asked to. But I've gotten over that. So, for the record, here goes:

"Billions and billions."

What makes "billions and billions" so popular? It used to be that "millions" was the byword for a large number. The enormously rich were millionaires. The population of the Earth at the time of Jesus was perhaps 250 million people. There were almost 4 million Americans at the time of the Constitutional Convention of 1787; by the beginning of World War II, there were 132 million. It is 93 million miles

'(150 million kilometers) from the Earth to the Sun. Approximately 40 million people were killed in World War I; 60 million in World War II. There are 31.7 million seconds in a year (as is easy enough to verify). The global nuclear arsenals at the end of the 1980s contained an equivalent explosive power sufficient to destroy 1 million Hiroshimas. For many purposes and for a long time, "million" was the quintessential big number.

But times have changed. Now the world has a clutch of Millionairesand not just because of inflation.

The age of the Earth is well-established at 4.6 billion years. The human population is pushing 6 billion people. Every birthday represents another billion kilometers around the Sun (the Earth is traveling around the Sun much faster than the Voyager spacecraft are traveling away from the Earth). Four B-2 bombers cost a billion dollars. (Some say 2 or even 4 billion.) The U.S. defense budget is, when hidden costs are accounted for, over $300 billion a year. The immediate fatalities in an all-out nuclear war between the United States and Russia are estimated to be around a billion people. A few inches are a billion atoms side by side. And there are all those billions of stars and galaxies.

In 1980, when the Cosmos television series was first shown, people were ready for billions. Mere millions had become a little downscale, unfashionable, miserly. Actually, the two words sound sufficiently alike that you have to make a serious effort to distinguish them. This is why, in Cosmos, I pronounced