Bill Bryson《A Short History of Nearly Everything》1-7

CONTENTS

introduction

part i lost in the cosmos 1 how to build a universe 2 welcome to the solar system 3 the reverend evanss universe

part ii the size of the earth 4 the measure of things 5 the stone-breakers 6 science red in tooth and claw 7 elemental matters

part iii anew age dawns 8 einsteins universe 9 the mighty atom 10 getting the lead out 11 muster marks quarks 12 the earth moves

part iv dangerous planet 13 bang! 14 the fire below 15 dangerous beauty

part v life itself 16 lonely planet 17 into the troposphere 18 the bounding main 19 the rise of life 20 small world 21 life goes on 22 good-bye to all that 23 the richness of being 24 cells 25 darwins singular notion 26 the stuff of life

part vi the road to us 27 ice time 28 the mysterious biped 29 the restless ape 30 good-bye

notes

bibliography

acknowledgments

the physicist leo szilard once announced to his friend hans bethe that he was thinking of keeping a diary: “i dont intend to publish. iam merely going to record the facts for the information of god.””dont you think god knows the facts?” bethe asked.

“yes,” said szilard.

“he knows the facts, but he does not know this version of the facts.”

-hans christian von baeyer,taming the atom

INTRODUCTION

welcome. and congratulations. i am delighted that you could make it. getting here wasnteasy, i know. in fact, i suspect it was a little tougher than you realize.

to begin with, for you to be here now trillions of drifting atoms had somehow to assemblein an intricate and intriguingly obliging manner to create you. its an arrangement sospecialized and particular that it has never been tried before and will only exist this once. forthe next many years (we hope) these tiny particles will uncomplainingly engage in all thebillions of deft, cooperative efforts necessary to keep you intact and let you experience thesupremely agreeable but generally underappreciated state known as existence.

why atoms take this trouble is a bit of a puzzle. being you is not a gratifying experience atthe atomic level. for all their devoted attention, your atoms dont actually care about you-indeed, dont even know that you are there. they dont even know that they are there. they aremindless particles, after all, and not even themselves alive. (it is a slightly arresting notionthat if you were to pick yourself apart with tweezers, one atom at a time, you would produce amound of fine atomic dust, none of which had ever been alive but all of which had once beenyou.) yet somehow for the period of your existence they will answer to a single overarching impulse: to keep you.

the bad news is that atoms are fickle and their time of devotion is fleeting-fleeting indeed.

even a long human life adds up to only about 650,000 hours. and when that modest milestone flashes past, or at some other point thereabouts, for reasons unknown your atoms will shut you down, silently disassemble, and go off to be other things. and that’s it for you.

still, you may rejoice that it happens at all. generally speaking in the universe it doesn’t, so far as we can tell. this is decidedly odd because the atoms that so liberally and congenially flock together to form living things on earth are exactly the same atoms that decline to do it elsewhere. whatever else it may be, at the level of chemistry life is curiously mundane:

carbon, hydrogen, oxygen, and nitrogen, a little calcium, a dash of sulfur, a light dusting of other very ordinary elements-nothing you wouldn’t find in any ordinary drugstore-and thats all you need. the only thing special about the atoms that make you is that they make you.

that is of course the miracle of life.

whether or not atoms make life in other corners of the universe, they make plenty else;indeed, they make everything else. without them there would be no water or air or rocks, no stars and planets, no distant gassy clouds or swirling nebulae or any of the other things that make the universe so usefully material. atoms are so numerous and necessary that we easily overlook that they needn’t actually exist at all. there is no law that requires the universe to fill itself with small particles of matter or to produce light and gravity and the other physical properties on which our existence hinges. there needn’t actually be a universe at all. for the longest time there wasn’t. there were no atoms and no universe for them to float about in.

there was nothing-nothing at all anywhere.

so thank goodness for atoms. but the fact that you have atoms and that they assemble insuch a willing manner is only part of what got you here. to be here now, alive in the twenty-first century and smart enough to know it, you also had to be the beneficiary of anextraordinary string of biological good fortune. survival on earth is a surprisingly trickybusiness. of the billions and billions of species of living thing that have existed since thedawn of time, most-99.99 percent-are no longer around. life on earth, you see, is not only brief but dismayingly tenuous. it is a curious feature of our existence that we come from aplanet that is very good at promoting life but even better at extinguishing it.

the average species on earth lasts for only about four million years, so if you wish to bearound for billions of years, you must be as fickle as the atoms that made you. you must beprepared to change everything about yourself-shape, size, color, species affiliation,everything-and to do so repeatedly. thats much easier said than done, because the process ofchange is random. to get from “protoplasmal primordial atomic globule” (as the gilbert andsullivan song put it) to sentient upright modern human has required you to mutate new traitsover and over in a precisely timely manner for an exceedingly long while. so at variousperiods over the last 3.8 billion years you have abhorred oxygen and then doted on it, grownfins and limbs and jaunty sails, laid eggs, flicked the air with a forked tongue, been sleek,been furry, lived underground, lived in trees, been as big as a deer and as small as a mouse,and a million things more. the tiniest deviation from any of these evolutionary shifts, and youmight now be licking algae from cave walls or lolling walrus-like on some stony shore ordisgorging air through a blowhole in the top of your head before diving sixty feet for amouthful of delicious sandworms.

not only have you been lucky enough to be attached since time immemorial to a favoredevolutionary line, but you have also been extremely-make that miraculously-fortunate in yourpersonal ancestry. consider the fact that for 3.8 billion years, a period of time older than theearths mountains and rivers and oceans, every one of your forebears on both sides has beenattractive enough to find a mate, healthy enough to reproduce, and sufficiently blessed by fateand circumstances to live long enough to do so. not one of your pertinent ancestors wassquashed, devoured, drowned, starved, stranded, stuck fast, untimely wounded, or otherwisedeflected from its lifes quest of delivering a tiny charge of genetic material to the rightpartner at the right moment in order to perpetuate the only possible sequence of hereditarycombinations that could result-eventually, astoundingly, and all too briefly-in you.

this is a book about how it happened-in particular how we went from there being nothing atall to there being something, and then how a little of that something turned into us, and alsosome of what happened in between and since. thats a great deal to cover, of course, which iswhy the book is called a short history of nearly everything, even though it isnt really. itcouldnt be. but with luck by the time we finish it will feel as if it is.

my own starting point, for what its worth, was an illustrated science book that i had as aclassroom text when i was in fourth or fifth grade. the book was a standard-issue 1950sschoolbookbattered, unloved, grimly hefty-but near the front it had an illustration that justcaptivated me: a cutaway diagram showing the earths interior as it would look if you cut intothe planet with a large knife and carefully withdrew a wedge representing about a quarter ofits bulk.

its hard to believe that there was ever a time when i had not seen such an illustrationbefore, but evidently i had not for i clearly remember being transfixed. i suspect, in honesty,my initial interest was based on a private image of streams of unsuspecting eastboundmotorists in the american plains states plunging over the edge of a sudden 4,000-mile-highcliff running between central america and the north pole, but gradually my attention did turnin a more scholarly manner to the scientific import of the drawing and the realization that theearth consisted of discrete layers, ending in the center with a glowing sphere of iron andnickel, which was as hot as the surface of the sun, according to the caption, and i rememberthinking with real wonder: “how do they know that?”i didnt doubt the correctness of the information for an instant-i still tend to trust thepronouncements of scientists in the way i trust those of surgeons, plumbers, and otherpossessors of arcane and privileged information-but i couldnt for the life of me conceive how any human mind could work out what spaces thousands of miles below us, that no eye hadever seen and no x ray could penetrate, could look like and be made of. to me that was just amiracle. that has been my position with science ever since.

excited, i took the book home that night and opened it before dinner-an action that i expect prompted my mother to feel my forehead and ask if i was all right-and, starting with the first page, i read.

and heres the thing. it wasnt exciting at all. it wasnt actually altogether comprehensible.

above all, it didnt answer any of the questions that the illustration stirred up in a normal inquiring mind: how did we end up with a sun in the middle of our planet? and if it is　burning away down there, why isnt the ground under our feet hot to the touch? and why isn’t the rest of the interior melting-or is it? and when the core at last burns itself out, will some of the earth slump into the void, leaving a giant sinkhole on the surface? and how do you know　this? how did you figure it out?

but the author was strangely silent on such details-indeed, silent on everything butanticlines, synclines, axial faults, and the like. it was as if he wanted to keep the good stuffsecret by making all of it soberly unfathomable. as the years passed, i began to suspect thatthis was not altogether a private impulse. there seemed to be a mystifying universalconspiracy among textbook authors to make certain the material they dealt with never strayedtoo near the realm of the mildly interesting and was always at least a longdistance phone callfrom the frankly interesting.

i now know that there is a happy abundance of science writers who pen the most lucid andthrilling prose-timothy ferris, richard fortey, and tim flannery are three that jump out froma single station of the alphabet (and thats not even to mention the late but godlike richardfeynman)-but sadly none of them wrote any textbook i ever used. all mine were written bymen (it was always men) who held the interesting notion that everything became clear whenexpressed as a formula and the amusingly deluded belief that the children of america wouldappreciate having chapters end with a section of questions they could mull over in their owntime. so i grew up convinced that science was supremely dull, but suspecting that it needntbe, and not really thinking about it at all if i could help it. this, too, became my position for along time.

then much later-about four or five years ago-i was on a long flight across the pacific,staring idly out the window at moonlit ocean, when it occurred to me with a certainuncomfortable forcefulness that i didnt know the first thing about the only planet i was evergoing to live on. i had no idea, for example, why the oceans were salty but the great lakeswerent. didnt have the faintest idea. i didnt know if the oceans were growing more saltywith time or less, and whether ocean salinity levels was something i should be concernedabout or not. (i am very pleased to tell you that until the late 1970s scientists didnt know theanswers to these questions either. they just didnt talk about it very audibly.)and ocean salinity of course represented only the merest sliver of my ignorance. i didntknow what a proton was, or a protein, didnt know a quark from a quasar, didnt understandhow geologists could look at a layer of rock on a canyon wall and tell you how old it was,didnt know anything really. i became gripped by a quiet, unwonted urge to know a littleabout these matters and to understand how people figured them out. that to me remained thegreatest of all amazements-how scientists work things out. how does anybody know howmuch the earth weighs or how old its rocks are or what really is way down there in thecenter? how can they know how and when the universe started and what it was like when itdid? how do they know what goes on inside an atom? and how, come to that-or perhapsabove all-can scientists so often seem to know nearly everything but then still cant predict anearthquake or even tell us whether we should take an umbrella with us to the races nextwednesday?

so i decided that i would devote a portion of my life-three years, as it now turns out-toreading books and journals and finding saintly, patient experts prepared to answer a lot ofoutstandingly dumb questions. the idea was to see if it isnt possible to understand andappreciate-marvel at, enjoy even-the wonder and accomplishments of science at a level thatisnt too technical or demanding, but isnt entirely superficial either.

that was my idea and my hope, and that is what the book that follows is intended to be.

anyway, we have a great deal of ground to cover and much less than 650,000 hours in whichto do it, so lets begin.

PART  I  LOST IN THE COSMOS

they’re all in the same plane.

they’re all going around in the same direction. . . .

it’s perfect, you know.

it’s gorgeous.

it’s almost uncanny.

-astronomer Geoffrey Marcy describing the solar system

1   HOW TO BUILD A UNIVERSENO MATTER

how hard you try you will never be able to grasp just how tiny, how spatiallyunassuming, is a proton. it is just way too small.

a proton is an infinitesimal part of an atom, which is itself of course an insubstantial thing.

protons are so small that a little dib of ink like the dot on this i can hold something in theregion of 500,000,000,000 of them, rather more than the number of seconds contained in halfa million years. so protons are exceedingly microscopic, to say the very least.

now imagine if you can (and of course you can’t) shrinking one of those protons down to abillionth of its normal size into a space so small that it would make a proton look enormous.

now pack into that tiny, tiny space about an ounce of matter. excellent. you are ready to starta universe.

i’m assuming of course that you wish to build an inflationary universe. if you’d preferinstead to build a more old-fashioned, standard big bang universe, you’ll need additionalmaterials. in fact, you will need to gather up everything there is every last mote and particle ofmatter between here and the edge of creation and squeeze it into a spot so infinitesimallycompact that it has no dimensions at all. it is known as a singularity.

in either case, get ready for a really big bang. naturally, you will wish to retire to a safeplace to observe the spectacle. unfortunately, there is nowhere to retire to because outside thesingularity there is no where. when the universe begins to expand, it won’t be spreading outto fill a larger emptiness. the only space that exists is the space it creates as it goes.

it is natural but wrong to visualize the singularity as a kind of pregnant dot hanging in adark, boundless void. but there is no space, no darkness. the singularity has no “around”

around it. there is no space for it to occupy, no place for it to be. we can’t even ask how longit has been there—whether it has just lately popped into being, like a good idea, or whether ithas been there forever, quietly awaiting the right moment. time doesn’t exist. there is no pastfor it to emerge from.

and so, from nothing, our universe begins.

in a single blinding pulse, a moment of glory much too swift and expansive for any form ofwords, the singularity assumes heavenly dimensions, space beyond conception. in the firstlively second (a second that many cosmologists will devote careers to shaving into ever-finerwafers) is produced gravity and the other forces that govern physics. in less than a minute theuniverse is a million billion miles across and growing fast. there is a lot of heat now, tenbillion degrees of it, enough to begin the nuclear reactions that create the lighter elements—principally hydrogen and helium, with a dash (about one atom in a hundred million) oflithium. in three minutes, 98 percent of all the matter there is or will ever be has beenproduced. we have a universe. it is a place of the most wondrous and gratifying possibility,and beautiful, too. and it was all done in about the time it takes to make a sandwich.

when this moment happened is a matter of some debate. cosmologists have long arguedover whether the moment of creation was 10 billion years ago or twice that or something inbetween. the consensus seems to be heading for a figure of about 13.7 billion years, but thesethings are notoriously difficult to measure, as we shall see further on. all that can really besaid is that at some indeterminate point in the very distant past, for reasons unknown, therecame the moment known to science as t = 0. we were on our way.

there is of course a great deal we don’t know, and much of what we think we know wehaven’t known, or thought we’ve known, for long. even the notion of the big bang is quite arecent one. the idea had been kicking around since the 1920s, when georges lema?tre, abelgian priest-scholar, first tentatively proposed it, but it didn’t really become an activenotion in cosmology until the mid-1960s when two young radio astronomers made anextraordinary and inadvertent discovery.

their names were arno penzias and robert wilson. in 1965, they were trying to make useof a large communications antenna owned by bell laboratories at holmdel, new jersey, butthey were troubled by a persistent background noise—a steady, steamy hiss that made anyexperimental work impossible. the noise was unrelenting and unfocused. it came from everypoint in the sky, day and night, through every season. for a year the young astronomers dideverything they could think of to track down and eliminate the noise. they tested everyelectrical system. they rebuilt instruments, checked circuits, wiggled wires, dusted plugs.

they climbed into the dish and placed duct tape over every seam and rivet. they climbedback into the dish with brooms and scrubbing brushes and carefully swept it clean of whatthey referred to in a later paper as “white dielectric material,” or what is known morecommonly as bird shit. nothing they tried worked.

unknown to them, just thirty miles away at princeton university, a team of scientists led byrobert dicke was working on how to find the very thing they were trying so diligently to getrid of. the princeton researchers were pursuing an idea that had been suggested in the 1940sby the russian-born astrophysicist george gamow that if you looked deep enough into spaceyou should find some cosmic background radiation left over from the big bang. gamowcalculated that by the time it crossed the vastness of the cosmos, the radiation would reachearth in the form of microwaves. in a more recent paper he had even suggested an instrumentthat might do the job: the bell antenna at holmdel. unfortunately, neither penzias andwilson, nor any of the princeton team, had read gamow’s paper.

the noise that penzias and wilson were hearing was, of course, the noise that gamow hadpostulated. they had found the edge of the universe, or at least the visible part of it, 90 billiontrillion miles away. they were “seeing” the first photons—the most ancient light in theuniverse—though time and distance had converted them to microwaves, just as gamow hadpredicted. in his book the inflationary universe , alan guth provides an analogy that helps toput this finding in perspective. if you think of peering into the depths of the universe as likelooking down from the hundredth floor of the empire state building (with the hundredth floorrepresenting now and street level representing the moment of the big bang), at the time ofwilson and penzias’s discovery the most distant galaxies anyone had ever detected were onabout the sixtieth floor, and the most distant things—quasars—were on about the twentieth.

penzias and wilson’s finding pushed our acquaintance with the visible universe to within halfan inch of the sidewalk.

still unaware of what caused the noise, wilson and penzias phoned dicke at princeton anddescribed their problem to him in the hope that he might suggest a solution. dicke realized at
once what the two young men had found. “well, boys, we’ve just been scooped,” he told hiscolleagues as he hung up the phone.

soon afterward the astrophysical journal published two articles: one by penzias andwilson describing their experience with the hiss, the other by dicke’s team explaining itsnature. although penzias and wilson had not been looking for cosmic background radiation,didn’t know what it was when they had found it, and hadn’t described or interpreted itscharacter in any paper, they received the 1978 nobel prize in physics. the princetonresearchers got only sympathy. according to dennis overbye in lonely hearts of the cosmos, neither penzias nor wilson altogether understood the significance of what they had founduntil they read about it in the new york times .

incidentally, disturbance from cosmic background radiation is something we have allexperienced. tune your television to any channel it doesn’t receive, and about 1 percent of thedancing static you see is accounted for by this ancient remnant of the big bang. the next timeyou complain that there is nothing on, remember that you can always watch the birth of theuniverse.

although everyone calls it the big bang, many books caution us not to think of it as anexplosion in the conventional sense. it was, rather, a vast, sudden expansion on a whoppingscale. so what caused it?

one notion is that perhaps the singularity was the relic of an earlier, collapsed universe—that we’re just one of an eternal cycle of expanding and collapsing universes, like the bladderon an oxygen machine. others attribute the big bang to what they call “a false vacuum” or “ascalar field” or “vacuum energy”—some quality or thing, at any rate, that introduced ameasure of instability into the nothingness that was. it seems impossible that you could getsomething from nothing, but the fact that once there was nothing and now there is a universeis evident proof that you can. it may be that our universe is merely part of many largeruniverses, some in different dimensions, and that big bangs are going on all the time all overthe place. or it may be that space and time had some other forms altogether before the bigbang—forms too alien for us to imagine—and that the big bang represents some sort oftransition phase, where the universe went from a form we can’t understand to one we almostcan. “these are very close to religious questions,” dr. andrei linde, a cosmologist atstanford, told the new york times in 2001.

the big bang theory isn’t about the bang itself but about what happened after the bang.

not long after, mind you. by doing a lot of math and watching carefully what goes on inparticle accelerators, scientists believe they can look back to 10-43seconds after the moment ofcreation, when the universe was still so small that you would have needed a microscope tofind it. we mustn’t swoon over every extraordinary number that comes before us, but it isperhaps worth latching on to one from time to time just to be reminded of their ungraspableand amazing breadth. thus 10-43is 0.0000000000000000000000000000000000000000001, orone 10 million trillion trillion trillionths of a second.

**a word on scientific notation: since very large numbers are cumbersome to write and nearly impossible to read, scientistsuse a shorthand involving powers (or multiples) of ten in which, for instance, 10,000,000,000 is written 1010 and 6,500,000becomes 6.5 x 106. the principle is based very simply on multiples of ten: 10 x 10 (or 100) becomes 102; 10 x 10 x 10 (or1,000) is 103; and so on, obviously and indefinitely. the little superscript number signifies the number of zeroes followingthe larger principal number. negative notations provide latter in print (especially essentially a mirror image, with thesuperscript number indicating the number of spaces to the right of the decimal point (so 10-4 means 0.0001). though i salutethe principle, it remains an amazement to me that anyone seeing “1.4 x 109 km3’ would see at once that that signifies 1.4
most of what we know, or believe we know, about the early moments of the universe isthanks to an idea called inflation theory first propounded in 1979 by a junior particlephysicist, then at stanford, now at mit, named alan guth. he was thirty-two years old and,by his own admission, had never done anything much before. he would probably never havehad his great theory except that he happened to attend a lecture on the big bang given bynone other than robert dicke. the lecture inspired guth to take an interest in cosmology, andin particular in the birth of the universe.

the eventual result was the inflation theory, which holds that a fraction of a moment afterthe dawn of creation, the universe underwent a sudden dramatic expansion. it inflated—ineffect ran away with itself, doubling in size every 10-34seconds. the whole episode may havelasted no more than 10-30seconds—that’s one million million million million millionths of asecond—but it changed the universe from something you could hold in your hand tosomething at least 10,000,000,000,000,000,000,000,000 times bigger. inflation theoryexplains the ripples and eddies that make our universe possible. without it, there would be noclumps of matter and thus no stars, just drifting gas and everlasting darkness.

according to guth’s theory, at one ten-millionth of a trillionth of a trillionth of a trillionthof a second, gravity emerged. after another ludicrously brief interval it was joined byelectromagnetism and the strong and weak nuclear forces—the stuff of physics. these werejoined an instant later by swarms of elementary particles—the stuff of stuff. from nothing atall, suddenly there were swarms of photons, protons, electrons, neutrons, and much else—between 1079and 1089of each, according to the standard big bang theory.

such quantities are of course ungraspable. it is enough to know that in a single crackinginstant we were endowed with a universe that was vast—at least a hundred billion light-yearsacross, according to the theory, but possibly any size up to infinite—and perfectly arrayed forthe creation of stars, galaxies, and other complex systems.

what is extraordinary from our point of view is how well it turned out for us. if theuniverse had formed just a tiny bit differently—if gravity were fractionally stronger orweaker, if the expansion had proceeded just a little more slowly or swiftly—then there mightnever have been stable elements to make you and me and the ground we stand on. had gravitybeen a trifle stronger, the universe itself might have collapsed like a badly erected tent,without precisely the right values to give it the right dimensions and density and componentparts. had it been weaker, however, nothing would have coalesced. the universe would haveremained forever a dull, scattered void.

this is one reason that some experts believe there may have been many other big bangs,perhaps trillions and trillions of them, spread through the mighty span of eternity, and that thereason we exist in this particular one is that this is one we could exist in. as edward p. tryonof columbia university once put it: “in answer to the question of why it happened, i offer themodest proposal that our universe is simply one of those things which happen from time tobillion cubic kilometers, and no less a wonder that they would choose the former over the in a book designed for the generalreader, where the example was found). on the assumption that many general readers are as unmathematical as i am, i will usethem sparingly, though they are occasionally unavoidable, not least in a chapter dealing with things on a cosmic scale.

time.” to which adds guth: “although the creation of a universe might be very unlikely,tryon emphasized that no one had counted the failed attempts.”

martin rees, britain’s astronomer royal, believes that there are many universes, possibly aninfinite number, each with different attributes, in different combinations, and that we simplylive in one that combines things in the way that allows us to exist. he makes an analogy witha very large clothing store: “if there is a large stock of clothing, you’re not surprised to find asuit that fits. if there are many universes, each governed by a differing set of numbers, therewill be one where there is a particular set of numbers suitable to life. we are in that one.”

rees maintains that six numbers in particular govern our universe, and that if any of thesevalues were changed even very slightly things could not be as they are. for example, for theuniverse to exist as it does requires that hydrogen be converted to helium in a precise butcomparatively stately manner—specifically, in a way that converts seven one-thousandths ofits mass to energy. lower that value very slightly—from 0.007 percent to 0.006 percent,say—and no transformation could take place: the universe would consist of hydrogen andnothing else. raise the value very slightly—to 0.008 percent—and bonding would be sowildly prolific that the hydrogen would long since have been exhausted. in either case, withthe slightest tweaking of the numbers the universe as we know and need it would not be here.

i should say that everything is just right so far. in the long term, gravity may turn out to be alittle too strong, and one day it may halt the expansion of the universe and bring it collapsingin upon itself, till it crushes itself down into another singularity, possibly to start the wholeprocess over again. on the other hand it may be too weak and the universe will keep racingaway forever until everything is so far apart that there is no chance of material interactions, sothat the universe becomes a place that is inert and dead, but very roomy. the third option isthat gravity is just right—“critical density” is the cosmologists’ term for it—and that it willhold the universe together at just the right dimensions to allow things to go on indefinitely.

cosmologists in their lighter moments sometimes call this the goldilocks effect—thateverything is just right. (for the record, these three possible universes are known respectivelyas closed, open, and flat.)now the question that has occurred to all of us at some point is: what would happen if youtraveled out to the edge of the universe and, as it were, put your head through the curtains?

where would your head be if it were no longer in the universe? what would you find beyond?

the answer, disappointingly, is that you can never get to the edge of the universe. that’s notbecause it would take too long to get there—though of course it would—but because even ifyou traveled outward and outward in a straight line, indefinitely and pugnaciously, you wouldnever arrive at an outer boundary. instead, you would come back to where you began (atwhich point, presumably, you would rather lose heart in the exercise and give up). the reasonfor this is that the universe bends, in a way we can’t adequately imagine, in conformance witheinstein’s theory of relativity (which we will get to in due course). for the moment it isenough to know that we are not adrift in some large, ever-expanding bubble. rather, spacecurves, in a way that allows it to be boundless but finite. space cannot even properly be saidto be expanding because, as the physicist and nobel laureate steven weinberg notes, “solar
systems and galaxies are not expanding, and space itself is not expanding.” rather, thegalaxies are rushing apart. it is all something of a challenge to intuition. or as the biologist j.

1. s. haldane once famously observed: “the universe is not only queerer than we suppose; itis queerer than we can suppose.”

the analogy that is usually given for explaining the curvature of space is to try to imaginesomeone from a universe of flat surfaces, who had never seen a sphere, being brought toearth. no matter how far he roamed across the planet’s surface, he would never find an edge.

he might eventually return to the spot where he had started, and would of course be utterlyconfounded to explain how that had happened. well, we are in the same position in space asour puzzled flatlander, only we are flummoxed by a higher dimension.

just as there is no place where you can find the edge of the universe, so there is no placewhere you can stand at the center and say: “this is where it all began. this is the centermostpoint of it all.” we are all at the center of it all. actually, we don’t know that for sure; wecan’t prove it mathematically. scientists just assume that we can’t really be the center of theuniverse—think what that would imply—but that the phenomenon must be the same for allobservers in all places. still, we don’t actually know.

for us, the universe goes only as far as light has traveled in the billions of years since theuniverse was formed. this visible universe—the universe we know and can talk about—is amillion million million million (that’s 1,000,000,000,000,000,000,000,000) miles across. butaccording to most theories the universe at large—the meta-universe, as it is sometimescalled—is vastly roomier still. according to rees, the number of light-years to the edge ofthis larger, unseen universe would be written not “with ten zeroes, not even with a hundred,but with millions.” in short, there’s more space than you can imagine already without going tothe trouble of trying to envision some additional beyond.

for a long time the big bang theory had one gaping hole that troubled a lot of people—namely that it couldn’t begin to explain how we got here. although 98 percent of all thematter that exists was created with the big bang, that matter consisted exclusively of lightgases: the helium, hydrogen, and lithium that we mentioned earlier. not one particle of theheavy stuff so vital to our own being—carbon, nitrogen, oxygen, and all the rest—emergedfrom the gaseous brew of creation. but—and here’s the troubling point—to forge these heavyelements, you need the kind of heat and energy of a big bang. yet there has been only onebig bang and it didn’t produce them. so where did they come from?

interestingly, the man who found the answer to that question was a cosmologist who heartily despised the big bang as a theory and coined the term “big bang” sarcastically, as away of mocking it. we’ll get to him shortly, but before we turn to the question of how we gothere, it might be worth taking a few minutes to consider just where exactly “here” is.

2  WELCOME TO THE SOLAR SYSTEMAS

astronomers these days can do the most amazing things. if someone struck a matchon the moon, they could spot the flare. from the tiniest throbs and wobbles of distant starsthey can infer the size and character and even potential habitability of planets much tooremote to be seen—planets so distant that it would take us half a million years in a spaceship to get there. with their radio telescopes they can capture wisps of radiation so preposterously faint that the total amount of energy collected from outside the solar system by all of them together since collecting began (in 1951) is “less than the energy of a single snowflakestriking the ground,” in the words of carl sagan.

in short, there isn’t a great deal that goes on in the universe that astronomers can’t findwhen they have a mind to. which is why it is all the more remarkable to reflect that until 1978no one had ever noticed that pluto has a moon. in the summer of that year, a youngastronomer named james christy at the u.s. naval observatory in flagstaff, arizona, wasmaking a routine examination of photographic images of pluto when he saw that there wassomething there—something blurry and uncertain but definitely other than pluto. consulting acolleague named robert harrington, he concluded that what he was looking at was a moon.

and it wasn’t just any moon. relative to the planet, it was the biggest moon in the solarsystem.

this was actually something of a blow to pluto’s status as a planet, which had never beenterribly robust anyway. since previously the space occupied by the moon and the spaceoccupied by pluto were thought to be one and the same, it meant that pluto was much smallerthan anyone had supposed—smaller even than mercury. indeed, seven moons in the solarsystem, including our own, are larger.

now a natural question is why it took so long for anyone to find a moon in our own solarsystem. the answer is that it is partly a matter of where astronomers point their instrumentsand partly a matter of what their instruments are designed to detect, and partly it’s just pluto.

mostly it’s where they point their instruments. in the words of the astronomer clarkchapman: “most people think that astronomers get out at night in observatories and scan theskies. that’s not true. almost all the telescopes we have in the world are designed to peer atvery tiny little pieces of the sky way off in the distance to see a quasar or hunt for black holesor look at a distant galaxy. the only real network of telescopes that scans the skies has beendesigned and built by the military.”

we have been spoiled by artists’ renderings into imagining a clarity of resolution thatdoesn’t exist in actual astronomy. pluto in christy’s photograph is faint and fuzzy—a piece ofcosmic lint—and its moon is not the romantically backlit, crisply delineated companion orbyou would get in a national geographic painting, but rather just a tiny and extremelyindistinct hint of additional fuzziness. such was the fuzziness, in fact, that it took seven yearsfor anyone to spot the moon again and thus independently confirm its existence.

one nice touch about christy’s discovery was that it happened in flagstaff, for it was therein 1930 that pluto had been found in the first place. that seminal event in astronomy waslargely to the credit of the astronomer percival lowell. lowell, who came from one of theoldest and wealthiest boston families (the one in the famous ditty about boston being thehome of the bean and the cod, where lowells spoke only to cabots, while cabots spoke onlyto god), endowed the famous observatory that bears his name, but is most indeliblyremembered for his belief that mars was covered with canals built by industrious martians for purposes of conveying water from polar regions to the dry but productive lands nearer theequator.

lowell’s other abiding conviction was that there existed, somewhere out beyond neptune,an undiscovered ninth planet, dubbed planet x. lowell based this belief on irregularities hedetected in the orbits of uranus and neptune, and devoted the last years of his life to trying tofind the gassy giant he was certain was out there. unfortunately, he died suddenly in 1916, atleast partly exhausted by his quest, and the search fell into abeyance while lowell’s heirssquabbled over his estate. however, in 1929, partly as a way of deflecting attention awayfrom the mars canal saga (which by now had become a serious embarrassment), the lowellobservatory directors decided to resume the search and to that end hired a young man fromkansas named clyde tombaugh.

tombaugh had no formal training as an astronomer, but he was diligent and he was astute,and after a year’s patient searching he somehow spotted pluto, a faint point of light in aglittery firmament. it was a miraculous find, and what made it all the more striking was thatthe observations on which lowell had predicted the existence of a planet beyond neptuneproved to be comprehensively erroneous. tombaugh could see at once that the new planetwas nothing like the massive gasball lowell had postulated, but any reservations he or anyoneelse had about the character of the new planet were soon swept aside in the delirium thatattended almost any big news story in that easily excited age. this was the first american-discovered planet, and no one was going to be distracted by the thought that it was really justa distant icy dot. it was named pluto at least partly because the first two letters made amonogram from lowell’s initials. lowell was posthumously hailed everywhere as a genius ofthe first order, and tombaugh was largely forgotten, except among planetary astronomers,who tend to revere him.

a few astronomers continue to think there may be a planet x out there—a real whopper,perhaps as much as ten times the size of jupiter, but so far out as to be invisible to us. (itwould receive so little sunlight that it would have almost none to reflect.) the idea is that itwouldn’t be a conventional planet like jupiter or saturn—it’s much too far away for that;we’re talking perhaps 4.5 trillion miles—but more like a sun that never quite made it. moststar systems in the cosmos are binary (double-starred), which makes our solitary sun a slightoddity.

as for pluto itself, nobody is quite sure how big it is, or what it is made of, what kind ofatmosphere it has, or even what it really is. a lot of astronomers believe it isn’t a planet at all,but merely the largest object so far found in a zone of galactic debris known as the kuiperbelt. the kuiper belt was actually theorized by an astronomer named f. c. leonard in 1930,but the name honors gerard kuiper, a dutch native working in america, who expanded theidea. the kuiper belt is the source of what are known as short-period comets—those thatcome past pretty regularly—of which the most famous is halley’s comet. the more reclusivelong-period comets (among them the recent visitors hale-bopp and hyakutake) come fromthe much more distant oort cloud, about which more presently.

it is certainly true that pluto doesn’t act much like the other planets. not only is it runty andobscure, but it is so variable in its motions that no one can tell you exactly where pluto will bea century hence. whereas the other planets orbit on more or less the same plane, pluto’sorbital path is tipped (as it were) out of alignment at an angle of seventeen degrees, like thebrim of a hat tilted rakishly on someone’s head. its orbit is so irregular that for substantialperiods on each of its lonely circuits around the sun it is closer to us than neptune is. for most of the 1980s and 1990s, neptune was in fact the solar system’s most far-flung planet.

only on february 11, 1999, did pluto return to the outside lane, there to remain for the next228 years.

so if pluto really is a planet, it is certainly an odd one. it is very tiny: just one-quarter of 1percent as massive as earth. if you set it down on top of the united states, it would cover notquite half the lower forty-eight states. this alone makes it extremely anomalous; it means thatour planetary system consists of four rocky inner planets, four gassy outer giants, and a tiny,solitary iceball. moreover, there is every reason to suppose that we may soon begin to findother even larger icy spheres in the same portion of space. then we will have problems. afterchristy spotted pluto’s moon, astronomers began to regard that section of the cosmos moreattentively and as of early december 2002 had found over six hundred additional trans-neptunian objects, or plutinos as they are alternatively called. one, dubbed varuna, is nearlyas big as pluto’s moon. astronomers now think there may be billions of these objects. thedifficulty is that many of them are awfully dark. typically they have an albedo, orreflectiveness, of just 4 percent, about the same as a lump of charcoal—and of course theselumps of charcoal are about four billion miles away.

and how far is that exactly? it’s almost beyond imagining. space, you see, is justenormous—just enormous. let’s imagine, for purposes of edification and entertainment, thatwe are about to go on a journey by rocketship. we won’t go terribly far—just to the edge ofour own solar system—but we need to get a fix on how big a place space is and what a smallpart of it we occupy.

now the bad news, i’m afraid, is that we won’t be home for supper. even at the speed oflight, it would take seven hours to get to pluto. but of course we can’t travel at anything likethat speed. we’ll have to go at the speed of a spaceship, and these are rather more lumbering.

the best speeds yet achieved by any human object are those of the voyager 1 and2 spacecraft,which are now flying away from us at about thirty-five thousand miles an hour.

the reason the voyager craft were launched when they were (in august and september1977) was that jupiter, saturn, uranus, and neptune were aligned in a way that happens onlyonce every 175 years. this enabled the two voyagers to use a “gravity assist” technique inwhich the craft were successively flung from one gassy giant to the next in a kind of cosmicversion of “crack the whip.” even so, it took them nine years to reach uranus and a dozen tocross the orbit of pluto. the good news is that if we wait until january 2006 (which is whennasa’s new horizons spacecraft is tentatively scheduled to depart for pluto) we can takeadvantage of favorable jovian positioning, plus some advances in technology, and get there inonly a decade or so—though getting home again will take rather longer, i’m afraid. at allevents, it’s going to be a long trip.

now the first thing you are likely to realize is that space is extremely well named and ratherdismayingly uneventful. our solar system may be the liveliest thing for trillions of miles, butall the visible stuff in it—the sun, the planets and their moons, the billion or so tumblingrocks of the asteroid belt, comets, and other miscellaneous drifting detritus—fills less than atrillionth of the available space. you also quickly realize that none of the maps you have everseen of the solar system were remotely drawn to scale. most schoolroom charts show theplanets coming one after the other at neighborly intervals—the outer giants actually castshadows over each other in many illustrations—but this is a necessary deceit to get them all
on the same piece of paper. neptune in reality isn’t just a little bit beyond jupiter, it’s waybeyond jupiter—five times farther from jupiter than jupiter is from us, so far out that itreceives only 3 percent as much sunlight as jupiter.

such are the distances, in fact, that it isn’t possible, in any practical terms, to draw the solarsystem to scale. even if you added lots of fold-out pages to your textbooks or used a reallylong sheet of poster paper, you wouldn’t come close. on a diagram of the solar system toscale, with earth reduced to about the diameter of a pea, jupiter would be over a thousand feetaway and pluto would be a mile and a half distant (and about the size of a bacterium, so youwouldn’t be able to see it anyway). on the same scale, proxima centauri, our nearest star,would be almost ten thousand miles away. even if you shrank down everything so that jupiterwas as small as the period at the end of this sentence, and pluto was no bigger than amolecule, pluto would still be over thirty-five feet away.

so the solar system is really quite enormous. by the time we reach pluto, we have come sofar that the sun—our dear, warm, skin-tanning, life-giving sun—has shrunk to the size of apinhead. it is little more than a bright star. in such a lonely void you can begin to understandhow even the most significant objects—pluto’s moon, for example—have escaped attention.

in this respect, pluto has hardly been alone. until the voyager expeditions, neptune wasthought to have two moons; voyager found six more. when i was a boy, the solar system wasthought to contain thirty moons. the total now is “at least ninety,” about a third of which havebeen found in just the last ten years.

the point to remember, of course, is that when considering the universe at large we don’tactually know what is in our own solar system.

now the other thing you will notice as we speed past pluto is that we are speeding pastpluto. if you check your itinerary, you will see that this is a trip to the edge of our solarsystem, and i’m afraid we’re not there yet. pluto may be the last object marked onschoolroom charts, but the system doesn’t end there. in fact, it isn’t even close to endingthere. we won’t get to the solar system’s edge until we have passed through the oort cloud, avast celestial realm of drifting comets, and we won’t reach the oort cloud for another—i’m sosorry about this—ten thousand years. far from marking the outer edge of the solar system, asthose schoolroom maps so cavalierly imply, pluto is barely one-fifty-thousandth of the way.

of course we have no prospect of such a journey. a trip of 240,000 miles to the moon stillrepresents a very big undertaking for us. a manned mission to mars, called for by the firstpresident bush in a moment of passing giddiness, was quietly dropped when someone workedout that it would cost $450 billion and probably result in the deaths of all the crew (their dnatorn to tatters by high-energy solar particles from which they could not be shielded).

based on what we know now and can reasonably imagine, there is absolutely no prospectthat any human being will ever visit the edge of our own solar system—ever. it is just too far.

as it is, even with the hubble telescope, we can’t see even into the oort cloud, so we don’tactually know that it is there. its existence is probable but entirely hypothetical.

*about all that can be said with confidence about the oort cloud is that it starts somewherebeyond pluto and stretches some two light-years out into the cosmos. the basic unit ofmeasure in the solar system is the astronomical unit, or au, representing the distance from*properly called the opik-oort cloud, it is named for the estonian astronomer ernst opik, who hypothesized itsexistence in 1932, and for the dutch astronomer jan oort, who refined the calculations eighteen years later.

the sun to the earth. pluto is about forty aus from us, the heart of the oort cloud about fiftythousand. in a word, it is remote.

but let’s pretend again that we have made it to the oort cloud. the first thing you mightnotice is how very peaceful it is out here. we’re a long way from anywhere now—so far fromour own sun that it’s not even the brightest star in the sky. it is a remarkable thought that thatdistant tiny twinkle has enough gravity to hold all these comets in orbit. it’s not a very strongbond, so the comets drift in a stately manner, moving at only about 220 miles an hour. fromtime to time some of these lonely comets are nudged out of their normal orbit by some slightgravitational perturbation—a passing star perhaps. sometimes they are ejected into theemptiness of space, never to be seen again, but sometimes they fall into a long orbit aroundthe sun. about three or four of these a year, known as long-period comets, pass through theinner solar system. just occasionally these stray visitors smack into something solid, likeearth. that’s why we’ve come out here now—because the comet we have come to see hasjust begun a long fall toward the center of the solar system. it is headed for, of all places,manson, iowa. it is going to take a long time to get there—three or four million years atleast—so we’ll leave it for now, and return to it much later in the story.

so that’s your solar system. and what else is out there, beyond the solar system? well,nothing and a great deal, depending on how you look at it.

in the short term, it’s nothing. the most perfect vacuum ever created by humans is not asempty as the emptiness of interstellar space. and there is a great deal of this nothingness untilyou get to the next bit of something. our nearest neighbor in the cosmos, proxima centauri,which is part of the three-star cluster known as alpha centauri, is 4.3 light-years away, a sissyskip in galactic terms, but that is still a hundred million times farther than a trip to the moon.

to reach it by spaceship would take at least twenty-five thousand years, and even if you madethe trip you still wouldn’t be anywhere except at a lonely clutch of stars in the middle of avast nowhere. to reach the next landmark of consequence, sirius, would involve another 4.6light-years of travel. and so it would go if you tried to star-hop your way across the cosmos.

just reaching the center of our own galaxy would take far longer than we have existed asbeings.

space, let me repeat, is enormous. the average distance between stars out there is 20million million miles. even at speeds approaching those of light, these are fantasticallychallenging distances for any traveling individual. of course, it is possible that alien beingstravel billions of miles to amuse themselves by planting crop circles in wiltshire orfrightening the daylights out of some poor guy in a pickup truck on a lonely road in arizona(they must have teenagers, after all), but it does seem unlikely.

still, statistically the probability that there are other thinking beings out there is good.

nobody knows how many stars there are in the milky way—estimates range from 100 billionor so to perhaps 400 billion—and the milky way is just one of 140 billion or so othergalaxies, many of them even larger than ours. in the 1960s, a professor at cornell namedfrank drake, excited by such whopping numbers, worked out a famous equation designed tocalculate the chances of advanced life in the cosmos based on a series of diminishingprobabilities.

under drake’s equation you divide the number of stars in a selected portion of the universeby the number of stars that are likely to have planetary systems; divide that by the number ofplanetary systems that could theoretically support life; divide that by the number on whichlife, having arisen, advances to a state of intelligence; and so on. at each such division, thenumber shrinks colossally—yet even with the most conservative inputs the number ofadvanced civilizations just in the milky way always works out to be somewhere in themillions.

what an interesting and exciting thought. we may be only one of millions of advancedcivilizations. unfortunately, space being spacious, the average distance between any two ofthese civilizations is reckoned to be at least two hundred light-years, which is a great dealmore than merely saying it makes it sound. it means for a start that even if these beings knowwe are here and are somehow able to see us in their telescopes, they’re watching light that leftearth two hundred years ago. so they’re not seeing you and me. they’re watching the frenchrevolution and thomas jefferson and people in silk stockings and powdered wigs—peoplewho don’t know what an atom is, or a gene, and who make their electricity by rubbing a rodof amber with a piece of fur and think that’s quite a trick. any message we receive from themis likely to begin “dear sire,” and congratulate us on the handsomeness of our horses and ourmastery of whale oil. two hundred light-years is a distance so far beyond us as to be, well,just beyond us.

so even if we are not really alone, in all practical terms we are. carl sagan calculated thenumber of probable planets in the universe at large at 10 billion trillion—a number vastlybeyond imagining. but what is equally beyond imagining is the amount of space throughwhich they are lightly scattered. “if we were randomly inserted into the universe,” saganwrote, “the chances that you would be on or near a planet would be less than one in a billiontrillion trillion.” (that’s 1033, or a one followed by thirty-three zeroes.) “worlds are precious.”

which is why perhaps it is good news that in February 1999 the international astronomical union ruled officially that pluto is a planet. the universe is a big and lonely place. we can do with all the neighbors we can get.

3  THE REVEREND EVANS’S UNIVERSE

when the skies are clear and the moon is not too bright, the reverend robert evans, aquiet and cheerful man, lugs a bulky telescope onto the back deck of his home in the blue mountains of Australia, about fifty miles west of Sydney, and does an extraordinary thing. helooks deep into the past and finds dying stars.

looking into the past is of course the easy part. glance at the night sky and what you see ishistory and lots of it—the stars not as they are now but as they were when their light left them. for all we know, the north star, our faithful companion, might actually have burnedout last january or in 1854 or at any time since the early fourteenth century and news of it justhasn’t reached us yet. the best we can say—can ever say—is that it was still burning on thisdate 680 years ago. stars die all the time. what bob evans does better than anyone else whohas ever tried is spot these moments of celestial farewell.

by day, evans is a kindly and now semiretired minister in the uniting church in australia,who does a bit of freelance work and researches the history of nineteenth-century religiousmovements. but by night he is, in his unassuming way, a titan of the skies. he huntssupernovae.

supernovae occur when a giant star, one much bigger than our own sun, collapses and thenspectacularly explodes, releasing in an instant the energy of a hundred billion suns, burningfor a time brighter than all the stars in its galaxy. “it’s like a trillion hydrogen bombs going offat once,” says evans. if a supernova explosion happened within five hundred light-years of us,we would be goners, according to evans—“it would wreck the show,” as he cheerfully puts it.

but the universe is vast, and supernovae are normally much too far away to harm us. in fact,most are so unimaginably distant that their light reaches us as no more than the faintesttwinkle. for the month or so that they are visible, all that distinguishes them from the otherstars in the sky is that they occupy a point of space that wasn’t filled before. it is theseanomalous, very occasional pricks in the crowded dome of the night sky that the reverendevans finds.

to understand what a feat this is, imagine a standard dining room table covered in a blacktablecloth and someone throwing a handful of salt across it. the scattered grains can bethought of as a galaxy. now imagine fifteen hundred more tables like the first one—enough tofill a wal-mart parking lot, say, or to make a single line two miles long—each with a randomarray of salt across it. now add one grain of salt to any table and let bob evans walk amongthem. at a glance he will spot it. that grain of salt is the supernova.

evans’s is a talent so exceptional that oliver sacks, in an anthropologist on mars, devotesa passage to him in a chapter on autistic savants—quickly adding that “there is no suggestionthat he is autistic.” evans, who has not met sacks, laughs at the suggestion that he might beeither autistic or a savant, but he is powerless to explain quite where his talent comes from.

“i just seem to have a knack for memorizing star fields,” he told me, with a franklyapologetic look, when i visited him and his wife, elaine, in their picture-book bungalow on atranquil edge of the village of hazelbrook, out where sydney finally ends and the boundlessaustralian bush begins. “i’m not particularly good at other things,” he added. “i don’tremember names well.”

“or where he’s put things,” called elaine from the kitchen.

he nodded frankly again and grinned, then asked me if i’d like to see his telescope. i hadimagined that evans would have a proper observatory in his backyard—a scaled-downversion of a mount wilson or palomar, with a sliding domed roof and a mechanized chair thatwould be a pleasure to maneuver. in fact, he led me not outside but to a crowded storeroomoff the kitchen where he keeps his books and papers and where his telescope—a whitecylinder that is about the size and shape of a household hot-water tank—rests in a homemade,swiveling plywood mount. when he wishes to observe, he carries them in two trips to a smalldeck off the kitchen. between the overhang of the roof and the feathery tops of eucalyptustrees growing up from the slope below, he has only a letter-box view of the sky, but he says itis more than good enough for his purposes. and there, when the skies are clear and the moonnot too bright, he finds his supernovae.

the term supernova was coined in the 1930s by a memorably odd astrophysicist namedfritz zwicky. born in bulgaria and raised in switzerland, zwicky came to the californiainstitute of technology in the 1920s and there at once distinguished himself by his abrasivepersonality and erratic talents. he didn’t seem to be outstandingly bright, and many of hiscolleagues considered him little more than “an irritating buffoon.” a fitness buff, he wouldoften drop to the floor of the caltech dining hall or other public areas and do one-armedpushups to demonstrate his virility to anyone who seemed inclined to doubt it. he wasnotoriously aggressive, his manner eventually becoming so intimidating that his closestcollaborator, a gentle man named walter baade, refused to be left alone with him. amongother things, zwicky accused baade, who was german, of being a nazi, which he was not. onat least one occasion zwicky threatened to kill baade, who worked up the hill at the mountwilson observatory, if he saw him on the caltech campus.

but zwicky was also capable of insights of the most startling brilliance. in the early 1930s,he turned his attention to a question that had long troubled astronomers: the appearance in thesky of occasional unexplained points of light, new stars. improbably he wondered if theneutron—the subatomic particle that had just been discovered in england by jameschadwick, and was thus both novel and rather fashionable—might be at the heart of things. itoccurred to him that if a star collapsed to the sort of densities found in the core of atoms, theresult would be an unimaginably compacted core. atoms would literally be crushed together,their electrons forced into the nucleus, forming neutrons. you would have a neutron star.

imagine a million really weighty cannonballs squeezed down to the size of a marble and—well, you’re still not even close. the core of a neutron star is so dense that a single spoonfulof matter from it would weigh 200 billion pounds. a spoonful! but there was more. zwickyrealized that after the collapse of such a star there would be a huge amount of energy leftover—enough to make the biggest bang in the universe. he called these resultant explosionssupernovae. they would be—they are—the biggest events in creation.

on january 15, 1934, the journal physical review published a very concise abstract of apresentation that had been conducted by zwicky and baade the previous month at stanforduniversity. despite its extreme brevity—one paragraph of twenty-four lines—the abstractcontained an enormous amount of new science: it provided the first reference to supernovaeand to neutron stars; convincingly explained their method of formation; correctly calculatedthe scale of their explosiveness; and, as a kind of concluding bonus, connected supernovaexplosions to the production of a mysterious new phenomenon called cosmic rays, which hadrecently been found swarming through the universe. these ideas were revolutionary to say theleast. neutron stars wouldn’t be confirmed for thirty-four years. the cosmic rays notion,
though considered plausible, hasn’t been verified yet. altogether, the abstract was, in thewords of caltech astrophysicist kip s. thorne, “one of the most prescient documents in thehistory of physics and astronomy.”

interestingly, zwicky had almost no understanding of why any of this would happen.

according to thorne, “he did not understand the laws of physics well enough to be able tosubstantiate his ideas.” zwicky’s talent was for big ideas. others—baade mostly—were leftto do the mathematical sweeping up.

zwicky also was the first to recognize that there wasn’t nearly enough visible mass in theuniverse to hold galaxies together and that there must be some other gravitational influence—what we now call dark matter. one thing he failed to see was that if a neutron star shrankenough it would become so dense that even light couldn’t escape its immense gravitationalpull. you would have a black hole. unfortunately, zwicky was held in such disdain by mostof his colleagues that his ideas attracted almost no notice. when, five years later, the greatrobert oppenheimer turned his attention to neutron stars in a landmark paper, he made not asingle reference to any of zwicky’s work even though zwicky had been working for years onthe same problem in an office just down the hall. zwicky’s deductions concerning dark matterwouldn’t attract serious attention for nearly four decades. we can only assume that he did alot of pushups in this period.

surprisingly little of the universe is visible to us when we incline our heads to the sky. onlyabout 6,000 stars are visible to the naked eye from earth, and only about 2,000 can be seenfrom any one spot. with binoculars the number of stars you can see from a single locationrises to about 50,000, and with a small two-inch telescope it leaps to 300,000. with a sixteen-inch telescope, such as evans uses, you begin to count not in stars but in galaxies. from hisdeck, evans supposes he can see between 50,000 and 100,000 galaxies, each containing tensof billions of stars. these are of course respectable numbers, but even with so much to take in,supernovae are extremely rare. a star can burn for billions of years, but it dies just once andquickly, and only a few dying stars explode. most expire quietly, like a campfire at dawn. in atypical galaxy, consisting of a hundred billion stars, a supernova will occur on average onceevery two or three hundred years. finding a supernova therefore was a little bit like standingon the observation platform of the empire state building with a telescope and searchingwindows around manhattan in the hope of finding, let us say, someone lighting a twenty-first-birthday cake.

so when a hopeful and softspoken minister got in touch to ask if they had any usable fieldcharts for hunting supernovae, the astronomical community thought he was out of his mind.

at the time evans had a ten-inch telescope—a very respectable size for amateur stargazingbut hardly the sort of thing with which to do serious cosmology—and he was proposing tofind one of the universe’s rarer phenomena. in the whole of astronomical history before evansstarted looking in 1980, fewer than sixty supernovae had been found. (at the time i visitedhim, in august of 2001, he had just recorded his thirty-fourth visual discovery; a thirty-fifthfollowed three months later and a thirty-sixth in early 2003.)evans, however, had certain advantages. most observers, like most people generally, are inthe northern hemisphere, so he had a lot of sky largely to himself, especially at first. he alsohad speed and his uncanny memory. large telescopes are cumbersome things, and much oftheir operational time is consumed with being maneuvered into position. evans could swing his little sixteen-inch telescope around like a tail gunner in a dogfight, spending no more thana couple of seconds on any particular point in the sky. in consequence, he could observeperhaps four hundred galaxies in an evening while a large professional telescope would belucky to do fifty or sixty.

looking for supernovae is mostly a matter of not finding them. from 1980 to 1996 heaveraged two discoveries a year—not a huge payoff for hundreds of nights of peering andpeering. once he found three in fifteen days, but another time he went three years withoutfinding any at all.

“there is actually a certain value in not finding anything,” he said. “it helps cosmologists towork out the rate at which galaxies are evolving. it’s one of those rare areas where theabsence of evidenceis evidence.”

on a table beside the telescope were stacks of photos and papers relevant to his pursuits,and he showed me some of them now. if you have ever looked through popular astronomicalpublications, and at some time you must have, you will know that they are generally full ofrichly luminous color photos of distant nebulae and the like—fairy-lit clouds of celestial lightof the most delicate and moving splendor. evans’s working images are nothing like that. theyare just blurry black-and-white photos with little points of haloed brightness. one he showedme depicted a swarm of stars with a trifling flare that i had to put close to my face to see.

this, evans told me, was a star in a constellation called fornax from a galaxy known toastronomy as ngc1365. (ngc stands for new general catalogue, where these things arerecorded. once it was a heavy book on someone’s desk in dublin; today, needless to say, it’sa database.) for sixty million silent years, the light from the star’s spectacular demise traveledunceasingly through space until one night in august of 2001 it arrived at earth in the form ofa puff of radiance, the tiniest brightening, in the night sky. it was of course robert evans onhis eucalypt-scented hillside who spotted it.

“there’s something satisfying, i think,” evans said, “about the idea of light traveling formillions of years through space and just at the right moment as it reaches earth someonelooks at the right bit of sky and sees it. it just seems right that an event of that magnitudeshould be witnessed.”

supernovae do much more than simply impart a sense of wonder. they come in severaltypes (one of them discovered by evans) and of these one in particular, known as a iasupernova, is important to astronomy because it always explodes in the same way, with thesame critical mass. for this reason it can be used as a standard candle to measure theexpansion rate of the universe.

in 1987 saul perlmutter at the lawrence berkeley lab in california, needing more iasupernovae than visual sightings were providing, set out to find a more systematic method ofsearching for them. perlmutter devised a nifty system using sophisticated computers andcharge-coupled devices—in essence, really good digital cameras. it automated supernovahunting. telescopes could now take thousands of pictures and let a computer detect thetelltale bright spots that marked a supernova explosion. in five years, with the new technique,perlmutter and his colleagues at berkeley found forty-two supernovae. now even amateursare finding supernovae with charge-coupled devices. “with ccds you can aim a telescope atthe sky and go watch television,” evans said with a touch of dismay. “it took all the romanceout of it.”

i asked him if he was tempted to adopt the new technology. “oh, no,” he said, “i enjoy myway too much. besides”—he gave a nod at the photo of his latest supernova and smiled—“ican still beat them sometimes.”

the question that naturally occurs is “what would it be like if a star exploded nearby?” ournearest stellar neighbor, as we have seen, is alpha centauri, 4.3 light-years away. i hadimagined that if there were an explosion there we would have 4.3 years to watch the light ofthis magnificent event spreading across the sky, as if tipped from a giant can. what would itbe like if we had four years and four months to watch an inescapable doom advancing towardus, knowing that when it finally arrived it would blow the skin right off our bones? wouldpeople still go to work? would farmers plant crops? would anyone deliver them to the stores?

weeks later, back in the town in new hampshire where i live, i put these questions to johnthorstensen, an astronomer at dartmouth college. “oh no,” he said, laughing. “the news ofsuch an event travels out at the speed of light, but so does the destructiveness, so you’d learnabout it and die from it in the same instant. but don’t worry because it’s not going to happen.”

for the blast of a supernova explosion to kill you, he explained, you would have to be“ridiculously close”—probably within ten light-years or so. “the danger would be varioustypes of radiation—cosmic rays and so on.” these would produce fabulous auroras,shimmering curtains of spooky light that would fill the whole sky. this would not be a goodthing. anything potent enough to put on such a show could well blow away themagnetosphere, the magnetic zone high above the earth that normally protects us fromultraviolet rays and other cosmic assaults. without the magnetosphere anyone unfortunateenough to step into sunlight would pretty quickly take on the appearance of, let us say, anovercooked pizza.

the reason we can be reasonably confident that such an event won’t happen in our cornerof the galaxy, thorstensen said, is that it takes a particular kind of star to make a supernova inthe first place. a candidate star must be ten to twenty times as massive as our own sun and“we don’t have anything of the requisite size that’s that close. the universe is a mercifully bigplace.” the nearest likely candidate he added, is betelgeuse, whose various sputterings havefor years suggested that something interestingly unstable is going on there. but betelgeuse isfifty thousand light-years away.

only half a dozen times in recorded history have supernovae been close enough to bevisible to the naked eye. one was a blast in 1054 that created the crab nebula. another, in1604, made a star bright enough to be seen during the day for over three weeks. the mostrecent was in 1987, when a supernova flared in a zone of the cosmos known as the largemagellanic cloud, but that was only barely visible and only in the southern hemisphere—andit was a comfortably safe 169,000 light-years away.

supernovae are significant to us in one other decidedly central way. without them wewouldn’t be here. you will recall the cosmological conundrum with which we ended the firstchapter—that the big bang created lots of light gases but no heavy elements. those camelater, but for a very long time nobody could figure out  how they came later. the problem wasthat you needed something really hot—hotter even than the middle of the hottest stars—toforge carbon and iron and the other elements without which we would be distressingly
immaterial. supernovae provided the explanation, and it was an english cosmologist almostas singular in manner as fritz zwicky who figured it out.

he was a yorkshireman named fred hoyle. hoyle, who died in 2001, was described in anobituary in nature as a “cosmologist and controversialist” and both of those he most certainlywas. he was, according to nature ’s obituary, “embroiled in controversy for most of his life”

and “put his name to much rubbish.” he claimed, for instance, and without evidence, that thenatural history museum’s treasured fossil of an archaeopteryx was a forgery along the linesof the piltdown hoax, causing much exasperation to the museum’s paleontologists, who had tospend days fielding phone calls from journalists from all over the world. he also believed thatearth was not only seeded by life from space but also by many of its diseases, such asinfluenza and bubonic plague, and suggested at one point that humans evolved projectingnoses with the nostrils underneath as a way of keeping cosmic pathogens from falling intothem.

it was he who coined the term “big bang,” in a moment of facetiousness, for a radiobroadcast in 1952. he pointed out that nothing in our understanding of physics could accountfor why everything, gathered to a point, would suddenly and dramatically begin to expand.

hoyle favored a steady-state theory in which the universe was constantly expanding andcontinually creating new matter as it went. hoyle also realized that if stars imploded theywould liberate huge amounts of heat—100 million degrees or more, enough to begin togenerate the heavier elements in a process known as nucleosynthesis. in 1957, working withothers, hoyle showed how the heavier elements were formed in supernova explosions. forthis work, w. a. fowler, one of his collaborators, received a nobel prize. hoyle, shamefully,did not.

according to hoyle’s theory, an exploding star would generate enough heat to create all thenew elements and spray them into the cosmos where they would form gaseous clouds—theinterstellar medium as it is known—that could eventually coalesce into new solar systems.

with the new theories it became possible at last to construct plausible scenarios for how wegot here. what we now think we know is this:

about 4.6 billion years ago, a great swirl of gas and dust some 15 billion miles acrossaccumulated in space where we are now and began to aggregate. virtually all of it—99.9percent of the mass of the solar system—went to make the sun. out of the floating materialthat was left over, two microscopic grains floated close enough together to be joined byelectrostatic forces. this was the moment of conception for our planet. all over the inchoatesolar system, the same was happening. colliding dust grains formed larger and larger clumps.

eventually the clumps grew large enough to be called planetesimals. as these endlesslybumped and collided, they fractured or split or recombined in endless random permutations,but in every encounter there was a winner, and some of the winners grew big enough todominate the orbit around which they traveled.

it all happened remarkably quickly. to grow from a tiny cluster of grains to a baby planetsome hundreds of miles across is thought to have taken only a few tens of thousands of years.

in just 200 million years, possibly less, the earth was essentially formed, though still moltenand subject to constant bombardment from all the debris that remained floating about.

at this point, about 4.5 billion years ago, an object the size of mars crashed into earth,blowing out enough material to form a companion sphere, the moon. within weeks, it isthought, the flung material had reassembled itself into a single clump, and within a year it had
formed into the spherical rock that companions us yet. most of the lunar material, it isthought, came from the earth’s crust, not its core, which is why the moon has so little ironwhile we have a lot. the theory, incidentally, is almost always presented as a recent one, butin fact it was first proposed in the 1940s by reginald daly of harvard. the only recent thingabout it is people paying any attention to it.

when earth was only about a third of its eventual size, it was probably already beginning toform an atmosphere, mostly of carbon dioxide, nitrogen, methane, and sulfur. hardly the sortof stuff that we would associate with life, and yet from this noxious stew life formed. carbondioxide is a powerful greenhouse gas. this was a good thing because the sun wassignificantly dimmer back then. had we not had the benefit of a greenhouse effect, the earthmight well have frozen over permanently, and life might never have gotten a toehold. butsomehow life did.

for the next 500 million years the young earth continued to be pelted relentlessly bycomets, meteorites, and other galactic debris, which brought water to fill the oceans and thecomponents necessary for the successful formation of life. it was a singularly hostileenvironment and yet somehow life got going. some tiny bag of chemicals twitched andbecame animate. we were on our way.

four billion years later people began to wonder how it had all happened. and it is there thatour story next takes us.

part  ii the size of the earthnature and nature’s laws lay hid innight;god said, let newton be! and allwas light.

-alexander pope

www.xiabook.com

4    THE MEASURE OF THINGS

if you had to select the least convivial scientific field trip of all time, you could certainlydo worse than the french royal academy of sciences’ peruvian expedition of 1735. led by ahydrologist named pierre bouguer and a soldier-mathematician named charles marie de lacondamine, it was a party of scientists and adventurers who traveled to peru with the purposeof triangulating distances through the andes.

at the time people had lately become infected with a powerful desire to understand theearth—to determine how old it was, and how massive, where it hung in space, and how it hadcome to be. the french party’s goal was to help settle the question of the circumference ofthe planet by measuring the length of one degree of meridian (or 1/360 of the distance aroundthe planet) along a line reaching from yarouqui, near quito, to just beyond cuenca in what isnow ecuador, a distance of about two hundred miles.

1almost at once things began to go wrong, sometimes spectacularly so. in quito, the visitorssomehow provoked the locals and were chased out of town by a mob armed with stones. soonafter, the expedition’s doctor was murdered in a misunderstanding over a woman. thebotanist became deranged. others died of fevers and falls. the third most senior member ofthe party, a man named pierre godin, ran off with a thirteen-year-old girl and could not beinduced to return.

at one point the group had to suspend work for eight months while la condamine rode off tolima to sort out a problem with their permits. eventually he and bouguer stopped speakingand refused to work together. everywhere the dwindling party went it was met with thedeepest suspicions from officials who found it difficult to believe that a group of frenchscientists would travel halfway around the world to measure the world. that made no sense atall. two and a half centuries later it still seems a reasonable question. why didn’t the frenchmake their measurements in france and save themselves all the bother and discomfort of theirandean adventure?

the answer lies partly with the fact that eighteenth-century scientists, the french in particular,seldom did things simply if an absurdly demanding alternative was available, and partly witha practical problem that had first arisen with the english astronomer edmond halley manyyears before—long before bouguer and la condamine dreamed of going to south america,much less had a reason for doing so.

* triangulation, their chosen method, was a popular technique based on the geometric fact that if you know thelength of one side of a triangle and the angles of two corners, you can work out all its other dimensions withoutleaving your chair. suppose, by way of example, that you and i decided we wished to know how far it is to themoon. using triangulation, the first thing we must do is put some distance between us, so lets say for argumentthat you stay in paris and i go to moscow and we both look at the moon at the same time. now if you imagine aline connecting the three principals of this exercise-that is, you and i and the moon-it forms a triangle. measurethe length of the baseline between you and me and the angles of our two corners and the rest can be simplycalculated. (because the interior angles of a triangle always add up to 180 degrees, if you know the sum of twoof the angles you can instantly calculate the third; and knowing the precise shape of a triangle and the length ofone side tells you the lengths of the other sides.) this was in fact the method use by a greek astronomer,hipparchus of nicaea, in 150 b.c. to work out the moons distance from earth. at ground level, the principles oftriangulation are the same, except that the triangles dont reach into space but rather are laid side to side on amap. in measuring a degree of meridian, the surveyors would create a sort of chain of triangles marching acrossthe landscape.

halley was an exceptional figure. in the course of a long and productive career, he was asea captain, a cartographer, a professor of geometry at the university of oxford, deputycontroller of the royal mint, astronomer royal, and inventor of the deep-sea diving bell. hewrote authoritatively on magnetism, tides, and the motions of the planets, and fondly on theeffects of opium. he invented the weather map and actuarial table, proposed methods forworking out the age of the earth and its distance from the sun, even devised a practicalmethod for keeping fish fresh out of season. the one thing he didn’t do, interestingly enough,was discover the comet that bears his name. he merely recognized that the comet he saw in1682 was the same one that had been seen by others in 1456, 1531, and 1607. it didn’tbecome halley’s comet until 1758, some sixteen years after his death.

for all his achievements, however, halley’s greatest contribution to human knowledge maysimply have been to take part in a modest scientific wager with two other worthies of his day:

robert hooke, who is perhaps best remembered now as the first person to describe a cell, andthe great and stately sir christopher wren, who was actually an astronomer first and architectsecond, though that is not often generally remembered now. in 1683, halley, hooke, andwren were dining in london when the conversation turned to the motions of celestial objects.

it was known that planets were inclined to orbit in a particular kind of oval known as anellipse—“a very specific and precise curve,” to quote richard feynman—but it wasn’tunderstood why. wren generously offered a prize worth forty shillings (equivalent to a coupleof weeks’ pay) to whichever of the men could provide a solution.

hooke, who was well known for taking credit for ideas that weren’t necessarily his own,claimed that he had solved the problem already but declined now to share it on the interestingand inventive grounds that it would rob others of the satisfaction of discovering the answer forthemselves. he would instead “conceal it for some time, that others might know how to valueit.” if he thought any more on the matter, he left no evidence of it. halley, however, becameconsumed with finding the answer, to the point that the following year he traveled tocambridge and boldly called upon the university’s lucasian professor of mathematics, isaacnewton, in the hope that he could help.

newton was a decidedly odd figure—brilliant beyond measure, but solitary, joyless, pricklyto the point of paranoia, famously distracted (upon swinging his feet out of bed in the morninghe would reportedly sometimes sit for hours, immobilized by the sudden rush of thoughts tohis head), and capable of the most riveting strangeness. he built his own laboratory, the firstat cambridge, but then engaged in the most bizarre experiments. once he inserted a bodkin—a long needle of the sort used for sewing leather—into his eye socket and rubbed it around“betwixt my eye and the bone as near to [the] backside of my eye as i could” just to see whatwould happen. what happened, miraculously, was nothing—at least nothing lasting. onanother occasion, he stared at the sun for as long as he could bear, to determine what effect itwould have upon his vision. again he escaped lasting damage, though he had to spend somedays in a darkened room before his eyes forgave him.

set atop these odd beliefs and quirky traits, however, was the mind of a supreme genius—though even when working in conventional channels he often showed a tendency topeculiarity. as a student, frustrated by the limitations of conventional mathematics, heinvented an entirely new form, the calculus, but then told no one about it for twenty-sevenyears. in like manner, he did work in optics that transformed our understanding of light andlaid the foundation for the science of spectroscopy, and again chose not to share the results forthree decades.

for all his brilliance, real science accounted for only a part of his interests. at least half hisworking life was given over to alchemy and wayward religious pursuits. these were not meredabblings but wholehearted devotions. he was a secret adherent of a dangerously hereticalsect called arianism, whose principal tenet was the belief that there had been no holy trinity(slightly ironic since newton’s college at cambridge was trinity). he spent endless hoursstudying the floor plan of the lost temple of king solomon in jerusalem (teaching himselfhebrew in the process, the better to scan original texts) in the belief that it held mathematicalclues to the dates of the second coming of christ and the end of the world. his attachment toalchemy was no less ardent. in 1936, the economist john maynard keynes bought a trunk ofnewton’s papers at auction and discovered with astonishment that they were overwhelminglypreoccupied not with optics or planetary motions, but with a single-minded quest to turn basemetals into precious ones. an analysis of a strand of newton’s hair in the 1970s found itcontained mercury—an element of interest to alchemists, hatters, and thermometer-makersbut almost no one else—at a concentration some forty times the natural level. it is perhapslittle wonder that he had trouble remembering to rise in the morning.

quite what halley expected to get from him when he made his unannounced visit in august1684 we can only guess. but thanks to the later account of a newton confidant, abrahamdemoivre, we do have a record of one of science’s most historic encounters:

in 1684 drhalley came to visit at cambridge [and] after they had some timetogether the drasked him what he thought the curve would be that would bedescribed by the planets supposing the force of attraction toward the sun to bereciprocal to the square of their distance from it.

this was a reference to a piece of mathematics known as the inverse square law, which halleywas convinced lay at the heart of the explanation, though he wasn’t sure exactly how.

srisaac replied immediately that it would be an [ellipse]. the doctor, struck withjoy & amazement, asked him how he knew it. ‘why,’ saith he, ‘i have calculatedit,’ whereupon drhalley asked him for his calculation without farther delay,srisaac looked among his papers but could not find it.

this was astounding—like someone saying he had found a cure for cancer but couldn’tremember where he had put the formula. pressed by halley, newton agreed to redo thecalculations and produce a paper. he did as promised, but then did much more. he retired fortwo years of intensive reflection and scribbling, and at length produced his masterwork: thephilosophiae naturalis principia mathematica or mathematical principles of naturalphilosophy, better known as the principia .

once in a great while, a few times in history, a human mind produces an observation soacute and unexpected that people can’t quite decide which is the more amazing—the fact orthe thinking of it. principia was one of those moments. it made newton instantly famous. for
the rest of his life he would be draped with plaudits and honors, becoming, among much else,the first person in britain knighted for scientific achievement. even the great germanmathematician gottfried von leibniz, with whom newton had a long, bitter fight over priorityfor the invention of the calculus, thought his contributions to mathematics equal to all theaccumulated work that had preceded him. “nearer the gods no mortal may approach,” wrotehalley in a sentiment that was endlessly echoed by his contemporaries and by many otherssince.

although the principia has been called “one of the most inaccessible books ever written”

(newton intentionally made it difficult so that he wouldn’t be pestered by mathematical“smatterers,” as he called them), it was a beacon to those who could follow it. it not onlyexplained mathematically the orbits of heavenly bodies, but also identified the attractive forcethat got them moving in the first place—gravity. suddenly every motion in the universe madesense.

at principia ’s heart were newton’s three laws of motion (which state, very baldly, that athing moves in the direction in which it is pushed; that it will keep moving in a straight lineuntil some other force acts to slow or deflect it; and that every action has an opposite andequal reaction) and his universal law of gravitation. this states that every object in theuniverse exerts a tug on every other. it may not seem like it, but as you sit here now you arepulling everything around you—walls, ceiling, lamp, pet cat—toward you with your own little(indeed, very little) gravitational field. and these things are also pulling on you. it wasnewton who realized that the pull of any two objects is, to quote feynman again,“proportional to the mass of each and varies inversely as the square of the distance betweenthem.” put another way, if you double the distance between two objects, the attractionbetween them becomes four times weaker. this can be expressed with the formulaf = gmmr2which is of course way beyond anything that most of us could make practical use of, but atleast we can appreciate that it is elegantly compact. a couple of brief multiplications, a simpledivision, and, bingo, you know your gravitational position wherever you go. it was the firstreally universal law of nature ever propounded by a human mind, which is why newton isregarded with such universal esteem.

principia’s production was not without drama. to halley’s horror, just as work wasnearing completion newton and hooke fell into dispute over the priority for the inversesquare law and newton refused to release the crucial third volume, without which the firsttwo made little sense. only with some frantic shuttle diplomacy and the most liberalapplications of flattery did halley manage finally to extract the concluding volume from theerratic professor.

halley’s traumas were not yet quite over. the royal society had promised to publish thework, but now pulled out, citing financial embarrassment. the year before the society hadbacked a costly flop called the history of fishes , and they now suspected that the market fora book on mathematical principles would be less than clamorous. halley, whose means werenot great, paid for the book’s publication out of his own pocket. newton, as was his custom,contributed nothing. to make matters worse, halley at this time had just accepted a positionas the society’s clerk, and he was informed that the society could no longer afford to provide him with a promised salary of ￡50 per annum. he was to be paid instead in copies of thehistory of fishes .

newton’s laws explained so many things—the slosh and roll of ocean tides, the motions ofplanets, why cannonballs trace a particular trajectory before thudding back to earth, why wearen’t flung into space as the planet spins beneath us at hundreds of miles an hour2—that ittook a while for all their implications to seep in. but one revelation became almostimmediately controversial.

this was the suggestion that the earth is not quite round. according to newton’s theory,the centrifugal force of the earth’s spin should result in a slight flattening at the poles and abulging at the equator, which would make the planet slightly oblate. that meant that thelength of a degree wouldn’t be the same in italy as it was in scotland. specifically, the lengthwould shorten as you moved away from the poles. this was not good news for those peoplewhose measurements of the earth were based on the assumption that the earth was a perfectsphere, which was everyone.

for half a century people had been trying to work out the size of the earth, mostly bymaking very exacting measurements. one of the first such attempts was by an englishmathematician named richard norwood. as a young man norwood had traveled to bermudawith a diving bell modeled on halley’s device, intending to make a fortune scooping pearlsfrom the seabed. the scheme failed because there were no pearls and anyway norwood’s belldidn’t work, but norwood was not one to waste an experience. in the early seventeenthcentury bermuda was well known among ships’ captains for being hard to locate. theproblem was that the ocean was big, bermuda small, and the navigational tools for dealingwith this disparity hopelessly inadequate. there wasn’t even yet an agreed length for anautical mile. over the breadth of an ocean the smallest miscalculations would becomemagnified so that ships often missed bermuda-sized targets by dismaying margins. norwood,whose first love was trigonometry and thus angles, decided to bring a little mathematical rigorto navigation and to that end he determined to calculate the length of a degree.

starting with his back against the tower of london, norwood spent two devoted yearsmarching 208 miles north to york, repeatedly stretching and measuring a length of chain ashe went, all the while making the most meticulous adjustments for the rise and fall of the landand the meanderings of the road. the final step was to measure the angle of the sun at york atthe same time of day and on the same day of the year as he had made his first measurement inlondon. from this, he reasoned he could determine the length of one degree of the earth’smeridian and thus calculate the distance around the whole. it was an almost ludicrouslyambitious undertaking—a mistake of the slightest fraction of a degree would throw the wholething out by miles—but in fact, as norwood proudly declaimed, he was accurate to “within ascantling”—or, more precisely, to within about six hundred yards. in metric terms, his figureworked out at 110.72 kilometers per degree of arc.

in 1637, norwood’s masterwork of navigation, the seaman’s practice , was published andfound an immediate following. it went through seventeen editions and was still in printtwenty-five years after his death. norwood returned to bermuda with his family, becoming a2how fast you are spinning depends on where you are. the speed of the earth’s spin varies from a little over1,000 miles an hour at the equator to 0 at the poles.

successful planter and devoting his leisure hours to his first love, trigonometry. he survivedthere for thirty-eight years and it would be pleasing to report that he passed this span inhappiness and adulation. in fact, he didn’t. on the crossing from england, his two young sonswere placed in a cabin with the reverend nathaniel white, and somehow so successfullytraumatized the young vicar that he devoted much of the rest of his career to persecutingnorwood in any small way he could think of.

norwood’s two daughters brought their father additional pain by making poor marriages.

one of the husbands, possibly incited by the vicar, continually laid small charges againstnorwood in court, causing him much exasperation and necessitating repeated trips acrossbermuda to defend himself. finally in the 1650s witch trials came to bermuda and norwoodspent his final years in severe unease that his papers on trigonometry, with their arcanesymbols, would be taken as communications with the devil and that he would be treated to adreadful execution. so little is known of norwood that it may in fact be that he deserved hisunhappy declining years. what is certainly true is that he got them.

meanwhile, the momentum for determining the earth’s circumference passed to france.

there, the astronomer jean picard devised an impressively complicated method oftriangulation involving quadrants, pendulum clocks, zenith sectors, and telescopes (forobserving the motions of the moons of jupiter). after two years of trundling and triangulatinghis way across france, in 1669 he announced a more accurate measure of 110.46 kilometersfor one degree of arc. this was a great source of pride for the french, but it was predicated onthe assumption that the earth was a perfect sphere—which newton now said it was not.

to complicate matters, after picard’s death the father-and-son team of giovanni andjacques cassini repeated picard’s experiments over a larger area and came up with results thatsuggested that the earth was fatter not at the equator but at the poles—that newton, in otherwords, was exactly wrong. it was this that prompted the academy of sciences to dispatchbouguer and la condamine to south america to take new measurements.

they chose the andes because they needed to measure near the equator, to determine ifthere really was a difference in sphericity there, and because they reasoned that mountainswould give them good sightlines. in fact, the mountains of peru were so constantly lost incloud that the team often had to wait weeks for an hour’s clear surveying. on top of that, theyhad selected one of the most nearly impossible terrains on earth. peruvians refer to theirlandscape as muy accidentado —“much accidented”—and this it most certainly is. thefrench had not only to scale some of the world’s most challenging mountains—mountainsthat defeated even their mules—but to reach the mountains they had to ford wild rivers, hacktheir way through jungles, and cross miles of high, stony desert, nearly all of it uncharted andfar from any source of supplies. but bouguer and la condamine were nothing if nottenacious, and they stuck to the task for nine and a half long, grim, sun-blistered years.

shortly before concluding the project, they received word that a second french team, takingmeasurements in northern scandinavia (and facing notable discomforts of their own, fromsquelching bogs to dangerous ice floes), had found that a degree was in fact longer near thepoles, as newton had promised. the earth was forty-three kilometers stouter when measuredequatorially than when measured from top to bottom around the poles.

bouguer and la condamine thus had spent nearly a decade working toward a result theydidn’t wish to find only to learn now that they weren’t even the first to find it. listlessly, they
completed their survey, which confirmed that the first french team was correct. then, still notspeaking, they returned to the coast and took separate ships home.

something else conjectured by newton in the principia was that a plumb bob hung near amountain would incline very slightly toward the mountain, affected by the mountain’sgravitational mass as well as by the earth’s. this was more than a curious fact. if youmeasured the deflection accurately and worked out the mass of the mountain, you couldcalculate the universal gravitational constant—that is, the basic value of gravity, known asg—and along with it the mass of the earth.

bouguer and la condamine had tried this on peru’s mount chimborazo, but had beendefeated by both the technical difficulties and their own squabbling, and so the notion laydormant for another thirty years until resurrected in england by nevil maskelyne, theastronomer royal. in dava sobel’s popular book longitude, maskelyne is presented as a ninnyand villain for failing to appreciate the brilliance of the clockmaker john harrison, and thismay be so, but we are indebted to him in other ways not mentioned in her book, not least forhis successful scheme to weigh the earth. maskelyne realized that the nub of the problem laywith finding a mountain of sufficiently regular shape to judge its mass.

at his urging, the royal society agreed to engage a reliable figure to tour the british islesto see if such a mountain could be found. maskelyne knew just such a person—theastronomer and surveyor charles mason. maskelyne and mason had become friends elevenyears earlier while engaged in a project to measure an astronomical event of great importance:

the passage of the planet venus across the face of the sun. the tireless edmond halley hadsuggested years before that if you measured one of these passages from selected points on theearth, you could use the principles of triangulation to work out the distance to the sun, andfrom that calibrate the distances to all the other bodies in the solar system.

unfortunately, transits of venus, as they are known, are an irregular occurrence. theycome in pairs eight years apart, but then are absent for a century or more, and there were nonein halley’s lifetime.

3but the idea simmered and when the next transit came due in 1761,nearly two decades after halley’s death, the scientific world was ready—indeed, more readythan it had been for an astronomical event before.

with the instinct for ordeal that characterized the age, scientists set off for more than ahundred locations around the globe—to siberia, china, south africa, indonesia, and thewoods of wisconsin, among many others. france dispatched thirty-two observers, britaineighteen more, and still others set out from sweden, russia, italy, germany, ireland, andelsewhere.

it was history’s first cooperative international scientific venture, and almost everywhere itran into problems. many observers were waylaid by war, sickness, or shipwreck. others madetheir destinations but opened their crates to find equipment broken or warped by tropical heat.

once again the french seemed fated to provide the most memorably unlucky participants.

jean chappe spent months traveling to siberia by coach, boat, and sleigh, nursing his delicateinstruments over every perilous bump, only to find the last vital stretch blocked by swollen3the next transit will be on june 8, 2004, with a second in 2012. there were none in the twentieth century.

rivers, the result of unusually heavy spring rains, which the locals were swift to blame on himafter they saw him pointing strange instruments at the sky. chappe managed to escape withhis life, but with no useful measurements.

unluckier still was guillaume le gentil, whose experiences are wonderfully summarizedby timothy ferris in coming of age in the milky way . le gentil set off from france a yearahead of time to observe the transit from india, but various setbacks left him still at sea on theday of the transit—just about the worst place to be since steady measurements wereimpossible on a pitching ship.

undaunted, le gentil continued on to india to await the next transit in 1769. with eightyears to prepare, he erected a first-rate viewing station, tested and retested his instruments,and had everything in a state of perfect readiness. on the morning of the second transit, june4, 1769, he awoke to a fine day, but, just as venus began its pass, a cloud slid in front of thesun and remained there for almost exactly the duration of the transit: three hours, fourteenminutes, and seven seconds.

stoically, le gentil packed up his instruments and set off for the nearest port, but en routehe contracted dysentery and was laid up for nearly a year. still weakened, he finally made itonto a ship. it was nearly wrecked in a hurricane off the african coast. when at last hereached home, eleven and a half years after setting off, and having achieved nothing, hediscovered that his relatives had had him declared dead in his absence and hadenthusiastically plundered his estate.

in comparison, the disappointments experienced by britain’s eighteen scattered observerswere mild. mason found himself paired with a young surveyor named jeremiah dixon andapparently they got along well, for they formed a lasting partnership. their instructions wereto travel to sumatra and chart the transit there, but after just one night at sea their ship wasattacked by a french frigate. (although scientists were in an internationally cooperativemood, nations weren’t.) mason and dixon sent a note to the royal society observing that itseemed awfully dangerous on the high seas and wondering if perhaps the whole thingoughtn’t to be called off. in reply they received a swift and chilly rebuke, noting that they hadalready been paid, that the nation and scientific community were counting on them, and thattheir failure to proceed would result in the irretrievable loss of their reputations. chastened,they sailed on, but en route word reached them that sumatra had fallen to the french and sothey observed the transit inconclusively from the cape of good hope. on the way home theystopped on the lonely atlantic outcrop of st. helena, where they met maskelyne, whoseobservations had been thwarted by cloud cover. mason and maskelyne formed a solidfriendship and spent several happy, and possibly even mildly useful, weeks charting tidalflows.

soon afterward, maskelyne returned to england where he became astronomer royal, andmason and dixon—now evidently more seasoned—set off for four long and often perilousyears surveying their way through 244 miles of dangerous american wilderness to settle aboundary dispute between the estates of william penn and lord baltimore and theirrespective colonies of pennsylvania and maryland. the result was the famous mason anddixon line, which later took on symbolic importance as the dividing line between the slaveand free states. (although the line was their principal task, they also contributed severalastronomical surveys, including one of the century’s most accurate measurements of a degree
of meridian—an achievement that brought them far more acclaim in england than the settlingof a boundary dispute between spoiled aristocrats.)back in europe, maskelyne and his counterparts in germany and france were forced to theconclusion that the transit measurements of 1761 were essentially a failure. one of theproblems, ironically, was that there were too many observations, which when broughttogether often proved contradictory and impossible to resolve. the successful charting of avenusian transit fell instead to a little-known yorkshire-born sea captain named james cook,who watched the 1769 transit from a sunny hilltop in tahiti, and then went on to chart andclaim australia for the british crown. upon his return there was now enough information forthe french astronomer joseph lalande to calculate that the mean distance from the earth tothe sun was a little over 150 million kilometers. (two further transits in the nineteenthcentury allowed astronomers to put the figure at 149.59 million kilometers, where it hasremained ever since. the precise distance, we now know, is 149.597870691 millionkilometers.) the earth at last had a position in space.

as for mason and dixon, they returned to england as scientific heroes and, for reasonsunknown, dissolved their partnership. considering the frequency with which they turn up atseminal events in eighteenth-century science, remarkably little is known about either man. nolikenesses exist and few written references. of dixon the dictionary of national biographynotes intriguingly that he was “said to have been born in a coal mine,” but then leaves it to thereader’s imagination to supply a plausible explanatory circumstance, and adds that he died atdurham in 1777. apart from his name and long association with mason, nothing more isknown.

mason is only slightly less shadowy. we know that in 1772, at maskelyne’s behest, heaccepted the commission to find a suitable mountain for the gravitational deflectionexperiment, at length reporting back that the mountain they needed was in the central scottishhighlands, just above loch tay, and was called schiehallion. nothing, however, wouldinduce him to spend a summer surveying it. he never returned to the field again. his nextknown movement was in 1786 when, abruptly and mysteriously, he turned up in philadelphiawith his wife and eight children, apparently on the verge of destitution. he had not been backto america since completing his survey there eighteen years earlier and had no known reasonfor being there, or any friends or patrons to greet him. a few weeks later he was dead.

with mason refusing to survey the mountain, the job fell to maskelyne. so for four monthsin the summer of 1774, maskelyne lived in a tent in a remote scottish glen and spent his daysdirecting a team of surveyors, who took hundreds of measurements from every possibleposition. to find the mass of the mountain from all these numbers required a great deal oftedious calculating, for which a mathematician named charles hutton was engaged. thesurveyors had covered a map with scores of figures, each marking an elevation at some pointon or around the mountain. it was essentially just a confusing mass of numbers, but huttonnoticed that if he used a pencil to connect points of equal height, it all became much moreorderly. indeed, one could instantly get a sense of the overall shape and slope of the mountain.

he had invented contour lines.

extrapolating from his schiehallion measurements, hutton calculated the mass of the earthat 5,000 million million tons, from which could reasonably be deduced the masses of all theother major bodies in the solar system, including the sun. so from this one experiment welearned the masses of the earth, the sun, the moon, the other planets and their moons, and gotcontour lines into the bargain—not bad for a summer’s work.

not everyone was satisfied with the results, however. the shortcoming of the schiehallionexperiment was that it was not possible to get a truly accurate figure without knowing theactual density of the mountain. for convenience, hutton had assumed that the mountain hadthe same density as ordinary stone, about 2.5 times that of water, but this was little more thanan educated guess.

one improbable-seeming person who turned his mind to the matter was a country parsonnamed john michell, who resided in the lonely yorkshire village of thornhill. despite hisremote and comparatively humble situation, michell was one of the great scientific thinkers ofthe eighteenth century and much esteemed for it.

among a great deal else, he perceived the wavelike nature of earthquakes, conducted muchoriginal research into magnetism and gravity, and, quite extraordinarily, envisioned thepossibility of black holes two hundred years before anyone else—a leap of intuitive deductionthat not even newton could make. when the german-born musician william herscheldecided his real interest in life was astronomy, it was michell to whom he turned forinstruction in making telescopes, a kindness for which planetary science has been in his debtever since.

4but of all that michell accomplished, nothing was more ingenious or had greater impactthan a machine he designed and built for measuring the mass of the earth. unfortunately, hedied before he could conduct the experiments and both the idea and the necessary equipmentwere passed on to a brilliant but magnificently retiring london scientist named henrycavendish.

cavendish is a book in himself. born into a life of sumptuous privilege—his grandfatherswere dukes, respectively, of devonshire and kent—he was the most gifted english scientistof his age, but also the strangest. he suffered, in the words of one of his few biographers,from shyness to a “degree bordering on disease.” any human contact was for him a source ofthe deepest discomfort.

once he opened his door to find an austrian admirer, freshly arrived from vienna, on thefront step. excitedly the austrian began to babble out praise. for a few moments cavendishreceived the compliments as if they were blows from a blunt object and then, unable to takeany more, fled down the path and out the gate, leaving the front door wide open. it was somehours before he could be coaxed back to the property. even his housekeeper communicatedwith him by letter.

although he did sometimes venture into society—he was particularly devoted to the weeklyscientific soirées of the great naturalist sir joseph banks—it was always made clear to theother guests that cavendish was on no account to be approached or even looked at. thosewho sought his views were advised to wander into his vicinity as if by accident and to “talk as4in 1781 herschel became the first person in the modern era to discover a planet. he wanted to call it george,after the british monarch, but was overruled. instead it became uranus.

it were into vacancy.” if their remarks were scientifically worthy they might receive amumbled reply, but more often than not they would hear a peeved squeak (his voice appearsto have been high pitched) and turn to find an actual vacancy and the sight of cavendishfleeing for a more peaceful corner.

his wealth and solitary inclinations allowed him to turn his house in clapham into a largelaboratory where he could range undisturbed through every corner of the physical sciences—electricity, heat, gravity, gases, anything to do with the composition of matter. the secondhalf of the eighteenth century was a time when people of a scientific bent grew intenselyinterested in the physical properties of fundamental things—gases and electricity inparticular—and began seeing what they could do with them, often with more enthusiasm thansense. in america, benjamin franklin famously risked his life by flying a kite in an electricalstorm. in france, a chemist named pilatre de rozier tested the flammability of hydrogen bygulping a mouthful and blowing across an open flame, proving at a stroke that hydrogen isindeed explosively combustible and that eyebrows are not necessarily a permanent feature ofone’s face. cavendish, for his part, conducted experiments in which he subjected himself tograduated jolts of electrical current, diligently noting the increasing levels of agony until hecould keep hold of his quill, and sometimes his consciousness, no longer.

in the course of a long life cavendish made a string of signal discoveries—among muchelse he was the first person to isolate hydrogen and the first to combine hydrogen and oxygento form water—but almost nothing he did was entirely divorced from strangeness. to thecontinuing exasperation of his fellow scientists, he often alluded in published work to theresults of contingent experiments that he had not told anyone about. in his secretiveness hedidn’t merely resemble newton, but actively exceeded him. his experiments with electricalconductivity were a century ahead of their time, but unfortunately remained undiscovereduntil that century had passed. indeed the greater part of what he did wasn’t known until thelate nineteenth century when the cambridge physicist james clerk maxwell took on the taskof editing cavendish’s papers, by which time credit had nearly always been given to others.

among much else, and without telling anyone, cavendish discovered or anticipated the lawof the conservation of energy, ohm’s law, dalton’s law of partial pressures, richter’s lawof reciprocal proportions, charles’s law of gases, and the principles of electricalconductivity. that’s just some of it. according to the science historian j. g. crowther, he alsoforeshadowed “the work of kelvin and g. h. darwin on the effect of tidal friction on slowingthe rotation of the earth, and larmor’s discovery, published in 1915, on the effect of localatmospheric cooling . . . the work of pickering on freezing mixtures, and some of the work ofrooseboom on heterogeneous equilibria.” finally, he left clues that led directly to thediscovery of the group of elements known as the noble gases, some of which are so elusivethat the last of them wasn’t found until 1962. but our interest here is in cavendish’s lastknown experiment when in the late summer of 1797, at the age of sixty-seven, he turned hisattention to the crates of equipment that had been left to him—evidently out of simplescientific respect—by john michell.

when assembled, michell’s apparatus looked like nothing so much as an eighteenth-century version of a nautilus weight-training machine. it incorporated weights,counterweights, pendulums, shafts, and torsion wires. at the heart of the machine were two350-pound lead balls, which were suspended beside two smaller spheres. the idea was tomeasure the gravitational deflection of the smaller spheres by the larger ones, which would allow the first measurement of the elusive force known as the gravitational constant, and fromwhich the weight (strictly speaking, the mass)5of the earth could be deduced.

because gravity holds planets in orbit and makes falling objects land with a bang, we tendto think of it as a powerful force, but it is not really. it is only powerful in a kind of collectivesense, when one massive object, like the sun, holds on to another massive object, like theearth. at an elemental level gravity is extraordinarily unrobust. each time you pick up a bookfrom a table or a dime from the floor you effortlessly overcome the combined gravitationalexertion of an entire planet. what cavendish was trying to do was measure gravity at thisextremely featherweight level.

delicacy was the key word. not a whisper of disturbance could be allowed into the roomcontaining the apparatus, so cavendish took up a position in an adjoining room and made hisobservations with a telescope aimed through a peephole. the work was incredibly exactingand involved seventeen delicate, interconnected measurements, which together took nearly ayear to complete. when at last he had finished his calculations, cavendish announced that theearth weighed a little over 13,000,000,000,000,000,000,000 pounds, or six billion trillionmetric tons, to use the modern measure. (a metric ton is 1,000 kilograms or 2,205 pounds.)today, scientists have at their disposal machines so precise they can detect the weight of asingle bacterium and so sensitive that readings can be disturbed by someone yawning seventy-five feet away, but they have not significantly improved on cavendish’s measurements of1797. the current best estimate for earth’s weight is 5.9725 billion trillion metric tons, adifference of only about 1 percent from cavendish’s finding. interestingly, all of this merelyconfirmed estimates made by newton 110 years before cavendish without any experimentalevidence at all.

so, by the late eighteenth century scientists knew very precisely the shape and dimensionsof the earth and its distance from the sun and planets; and now cavendish, without evenleaving home, had given them its weight. so you might think that determining the age of theearth would be relatively straightforward. after all, the necessary materials were literally attheir feet. but no. human beings would split the atom and invent television, nylon, and instantcoffee before they could figure out the age of their own planet.

to understand why, we must travel north to scotland and begin with a brilliant and genialman, of whom few have ever heard, who had just invented a new science called geology.

5to a physicist, mass and weight are two quite different things. your mass stays the same wherever you go, butyour weight varies depending on how far you are from the center of some other massive object like a planet.

travel to the moon and you will be much lighter but no less massive. on earth, for all practical purposes, massand weight are the same and so the terms can be treated as synonymous. at least outside the classroom.

5    THE STONE-BREAKERS

at just the time that henry cavendish was completing his experiments in london, fourhundred miles away in edinburgh another kind of concluding moment was about to take placewith the death of james hutton. this was bad news for hutton, of course, but good news forscience as it cleared the way for a man named john playfair to rewrite hutton’s work withoutfear of embarrassment.

hutton was by all accounts a man of the keenest insights and liveliest conversation, a delightin company, and without rival when it came to understanding the mysterious slow processesthat shaped the earth. unfortunately, it was beyond him to set down his notions in a form thatanyone could begin to understand. he was, as one biographer observed with an all but audiblesigh, “almost entirely innocent of rhetorical accomplishments.” nearly every line he pennedwas an invitation to slumber. here he is in his 1795 masterwork, a theory of the earth withproofs and illustrations , discussing . . . something:

the world which we inhabit is composed of the materials, not of the earth whichwas the immediate predecessor of the present, but of the earth which, in ascendingfrom the present, we consider as the third, and which had preceded the land thatwas above the surface of the sea, while our present land was yet beneath the waterof the ocean.

yet almost singlehandedly, and quite brilliantly, he created the science of geology andtransformed our understanding of the earth. hutton was born in 1726 into a prosperousscottish family, and enjoyed the sort of material comfort that allowed him to pass much of hislife in a genially expansive round of light work and intellectual betterment. he studiedmedicine, but found it not to his liking and turned instead to farming, which he followed in arelaxed and scientific way on the family estate in berwickshire. tiring of field and flock, in1768 he moved to edinburgh, where he founded a successful business producing salammoniac from coal soot, and busied himself with various scientific pursuits. edinburgh atthat time was a center of intellectual vigor, and hutton luxuriated in its enriching possibilities.

he became a leading member of a society called the oyster club, where he passed hisevenings in the company of men such as the economist adam smith, the chemist josephblack, and the philosopher david hume, as well as such occasional visiting sparks asbenjamin franklin and james watt.

in the tradition of the day, hutton took an interest in nearly everything, from mineralogy tometaphysics. he conducted experiments with chemicals, investigated methods of coal miningand canal building, toured salt mines, speculated on the mechanisms of heredity, collectedfossils, and propounded theories on rain, the composition of air, and the laws of motion,among much else. but his particular interest was geology.

among the questions that attracted interest in that fanatically inquisitive age was one thathad puzzled people for a very long time—namely, why ancient clamshells and other marinefossils were so often found on mountaintops. how on earth did they get there? those whothought they had a solution fell into two opposing camps. one group, known as theneptunists, was convinced that everything on earth, including seashells in improbably lofty places, could be explained by rising and falling sea levels. they believed that mountains,hills, and other features were as old as the earth itself, and were changed only when watersloshed over them during periods of global flooding.

opposing them were the plutonists, who noted that volcanoes and earthquakes, amongother enlivening agents, continually changed the face of the planet but clearly owed nothing towayward seas. the plutonists also raised awkward questions about where all the water wentwhen it wasn’t in flood. if there was enough of it at times to cover the alps, then where, pray,was it during times of tranquility, such as now? their belief was that the earth was subject toprofound internal forces as well as surface ones. however, they couldn’t convincingly explainhow all those clamshells got up there.

it was while puzzling over these matters that hutton had a series of exceptional insights.

from looking at his own farmland, he could see that soil was created by the erosion of rocksand that particles of this soil were continually washed away and carried off by streams andrivers and redeposited elsewhere. he realized that if such a process were carried to its naturalconclusion then earth would eventually be worn quite smooth. yet everywhere around himthere were hills. clearly there had to be some additional process, some form of renewal anduplift, that created new hills and mountains to keep the cycle going. the marine fossils onmountaintops, he decided, had not been deposited during floods, but had risen along with themountains themselves. he also deduced that it was heat within the earth that created newrocks and continents and thrust up mountain chains. it is not too much to say that geologistswouldn’t grasp the full implications of this thought for two hundred years, when finally theyadopted plate tectonics. above all, what hutton’s theories suggested was that earth processesrequired huge amounts of time, far more than anyone had ever dreamed. there were enoughinsights here to transform utterly our understanding of the earth.

in 1785, hutton worked his ideas up into a long paper, which was read at consecutivemeetings of the royal society of edinburgh. it attracted almost no notice at all. it’s not hardto see why. here, in part, is how he presented it to his audience:

in the one case, the forming cause is in the body which is separated; for, after thebody has been actuated by heat, it is by the reaction of the proper matter of thebody, that the chasm which constitutes the vein is formed. in the other case, again,the cause is extrinsic in relation to the body in which the chasm is formed. therehas been the most violent fracture and divulsion; but the cause is still to seek; andit appears not in the vein; for it is not every fracture and dislocation of the solidbody of our earth, in which minerals, or the proper substances of mineral veins,are found.

needless to say, almost no one in the audience had the faintest idea what he was talkingabout. encouraged by his friends to expand his theory, in the touching hope that he mightsomehow stumble onto clarity in a more expansive format, hutton spent the next ten yearspreparing his magnum opus, which was published in two volumes in 1795.

together the two books ran to nearly a thousand pages and were, remarkably, worse thaneven his most pessimistic friends had feared. apart from anything else, nearly half the completed work now consisted of quotations from french sources, still in the original french.

a third volume was so unenticing that it wasn’t published until 1899, more than a centuryafter hutton’s death, and the fourth and concluding volume was never published at all.

hutton’s theory of the earth is a strong candidate for the least read important book in science(or at least would be if there weren’t so many others). even charles lyell, the greatestgeologist of the following century and a man who read everything, admitted he couldn’t getthrough it.

luckily hutton had a boswell in the form of john playfair, a professor of mathematics atthe university of edinburgh and a close friend, who could not only write silken prose but—thanks to many years at hutton’s elbow—actually understood what hutton was trying to say,most of the time. in 1802, five years after hutton’s death, playfair produced a simplifiedexposition of the huttonian principles, entitled illustrations of the huttonian theory of theearth. the book was gratefully received by those who took an active interest in geology,which in 1802 was not a large number. that, however, was about to change. and how.

in the winter of 1807, thirteen like-minded souls in london got together at the freemasonstavern at long acre, in covent garden, to form a dining club to be called the geologicalsociety. the idea was to meet once a month to swap geological notions over a glass or two ofmadeira and a convivial dinner. the price of the meal was set at a deliberately hefty fifteenshillings to discourage those whose qualifications were merely cerebral. it soon becameapparent, however, that there was a demand for something more properly institutional, with apermanent headquarters, where people could gather to share and discuss new findings. inbarely a decade membership grew to four hundred—still all gentlemen, of course—and thegeological was threatening to eclipse the royal as the premier scientific society in thecountry.

the members met twice a month from november until june, when virtually all of themwent off to spend the summer doing fieldwork. these weren’t people with a pecuniary interestin minerals, you understand, or even academics for the most part, but simply gentlemen withthe wealth and time to indulge a hobby at a more or less professional level. by 1830, therewere 745 of them, and the world would never see the like again.

it is hard to imagine now, but geology excited the nineteenth century—positively grippedit—in a way that no science ever had before or would again. in 1839, when roderickmurchison published the silurian system, a plump and ponderous study of a type of rockcalled greywacke, it was an instant bestseller, racing through four editions, even though it costeight guineas a copy and was, in true huttonian style, unreadable. (as even a murchisonsupporter conceded, it had “a total want of literary attractiveness.”) and when, in 1841, thegreat charles lyell traveled to america to give a series of lectures in boston, selloutaudiences of three thousand at a time packed into the lowell institute to hear his tranquilizingdescriptions of marine zeolites and seismic perturbations in campania.

throughout the modern, thinking world, but especially in britain, men of learning venturedinto the countryside to do a little “stone-breaking,” as they called it. it was a pursuit takenseriously, and they tended to dress with appropriate gravity, in top hats and dark suits, exceptfor the reverend william buckland of oxford, whose habit it was to do his fieldwork in anacademic gown.

the field attracted many extraordinary figures, not least the aforementioned murchison,who spent the first thirty or so years of his life galloping after foxes, converting aeronauticallychallenged birds into puffs of drifting feathers with buckshot, and showing no mental agilitywhatever beyond that needed to read the times or play a hand of cards. then he discoveredan interest in rocks and became with rather astounding swiftness a titan of geologicalthinking.

then there was dr. james parkinson, who was also an early socialist and author of manyprovocative pamphlets with titles like “revolution without bloodshed.” in 1794, he wasimplicated in a faintly lunatic-sounding conspiracy called “the pop-gun plot,” in which it wasplanned to shoot king george iii in the neck with a poisoned dart as he sat in his box at thetheater. parkinson was hauled before the privy council for questioning and came within anace of being dispatched in irons to australia before the charges against him were quietlydropped. adopting a more conservative approach to life, he developed an interest in geologyand became one of the founding members of the geological society and the author of animportant geological text, organic remains of a former world, which remained in print forhalf a century. he never caused trouble again. today, however, we remember him for hislandmark study of the affliction then called the “shaking palsy,” but known ever since asparkinson’s disease. (parkinson had one other slight claim to fame. in 1785, he becamepossibly the only person in history to win a natural history museum in a raffle. the museum,in london’s leicester square, had been founded by sir ashton lever, who had driven himselfbankrupt with his unrestrained collecting of natural wonders. parkinson kept the museum until1805, when he could no longer support it and the collection was broken up and sold.)not quite as remarkable in character but more influential than all the others combined wascharles lyell. lyell was born in the year that hutton died and only seventy miles away, in thevillage of kinnordy. though scottish by birth, he grew up in the far south of england, in thenew forest of hampshire, because his mother was convinced that scots were feckless drunks.

as was generally the pattern with nineteenth-century gentlemen scientists, lyell came from abackground of comfortable wealth and intellectual vigor. his father, also named charles, hadthe unusual distinction of being a leading authority on the poet dante and on mosses.

(orthotricium lyelli, which most visitors to the english countryside will at some time have saton, is named for him.) from his father lyell gained an interest in natural history, but it was atoxford, where he fell under the spell of the reverend william buckland—he of the flowinggowns—that the young lyell began his lifelong devotion to geology.

buckland was a bit of a charming oddity. he had some real achievements, but he isremembered at least as much for his eccentricities. he was particularly noted for a menagerieof wild animals, some large and dangerous, that were allowed to roam through his house andgarden, and for his desire to eat his way through every animal in creation. depending onwhim and availability, guests to buckland’s house might be served baked guinea pig, mice inbatter, roasted hedgehog, or boiled southeast asian sea slug. buckland was able to find meritin them all, except the common garden mole, which he declared disgusting. almostinevitably, he became the leading authority on coprolites—fossilized feces—and had a tablemade entirely out of his collection of specimens.

even when conducting serious science his manner was generally singular. once mrs.

buckland found herself being shaken awake in the middle of the night, her husband crying inexcitement: “my dear, i believe that cheirotherium ’s footsteps are undoubtedly testudinal.”

together they hurried to the kitchen in their nightclothes. mrs. buckland made a flour paste,which she spread across the table, while the reverend buckland fetched the family tortoise.

plunking it onto the paste, they goaded it forward and discovered to their delight that itsfootprints did indeed match those of the fossil buckland had been studying. charles darwinthought buckland a buffoon—that was the word he used—but lyell appeared to find himinspiring and liked him well enough to go touring with him in scotland in 1824. it was soonafter this trip that lyell decided to abandon a career in law and devote himself to geology full-time.

lyell was extremely shortsighted and went through most of his life with a pained squint,which gave him a troubled air. (eventually he would lose his sight altogether.) his other slightpeculiarity was the habit, when distracted by thought, of taking up improbable positions onfurniture—lying across two chairs at once or “resting his head on the seat of a chair, whilestanding up” (to quote his friend darwin). often when lost in thought he would slink so lowin a chair that his buttocks would all but touch the floor. lyell’s only real job in life was asprofessor of geology at king’s college in london from 1831 to 1833. it was around this timethat he produced the principles of geology, published in three volumes between 1830 and1833, which in many ways consolidated and elaborated upon the thoughts first voiced byhutton a generation earlier. (although lyell never read hutton in the original, he was a keenstudent of playfair’s reworked version.)between hutton’s day and lyell’s there arose a new geological controversy, which largelysuperseded, but is often confused with, the old neptunian–plutonian dispute. the new battlebecame an argument between catastrophism and uniformitarianism—unattractive terms for animportant and very long-running dispute. catastrophists, as you might expect from the name,believed that the earth was shaped by abrupt cataclysmic events—floods principally, which iswhy catastrophism and neptunism are often wrongly bundled together. catastrophism wasparticularly comforting to clerics like buckland because it allowed them to incorporate thebiblical flood of noah into serious scientific discussions. uniformitarians by contrast believedthat changes on earth were gradual and that nearly all earth processes happened slowly, overimmense spans of time. hutton was much more the father of the notion than lyell, but it waslyell most people read, and so he became in most people’s minds, then and now, the father ofmodern geological thought.

lyell believed that the earth’s shifts were uniform and steady—that everything that hadever happened in the past could be explained by events still going on today. lyell and hisadherents didn’t just disdain catastrophism, they detested it. catastrophists believed thatextinctions were part of a series in which animals were repeatedly wiped out and replacedwith new sets—a belief that the naturalist t. h. huxley mockingly likened to “a succession ofrubbers of whist, at the end of which the players upset the table and called for a new pack.” itwas too convenient a way to explain the unknown. “never was there a dogma more calculatedto foster indolence, and to blunt the keen edge of curiosity,” sniffed lyell.

lyell’s  oversights  were  not  inconsiderable. he failed to explain convincingly howmountain ranges were formed and overlooked glaciers as an agent of change. he refused toaccept louis agassiz’s idea of ice ages—“the refrigeration of the globe,” as he dismissivelytermed it—and was confident that mammals “would be found in the oldest fossiliferousbeds.” he rejected the notion that animals and plants suffered sudden annihilations, andbelieved that all the principal animal groups—mammals, reptiles, fish, and so on—hadcoexisted since the dawn of time. on all of these he would ultimately be proved wrong.

yet it would be nearly impossible to overstate lyell’s influence. the principles of geologywent through twelve editions in lyell’s lifetime and contained notions that shaped geological
thinking far into the twentieth century. darwin took a first edition with him on thebeaglevoyage and wrote afterward that “the great merit of the principles was that it altered thewhole tone of one’s mind, and therefore that, when seeing a thing never seen by lyell, one yetsaw it partially through his eyes.” in short, he thought him nearly a god, as did many of hisgeneration. it is a testament to the strength of lyell’s sway that in the 1980s when geologistshad to abandon just a part of it to accommodate the impact theory of extinctions, it nearlykilled them. but that is another chapter.

meanwhile, geology had a great deal of sorting out to do, and not all of it went smoothly.

from the outset geologists tried to categorize rocks by the periods in which they were laiddown, but there were often bitter disagreements about where to put the dividing lines—nonemore so than a long-running debate that became known as the great devonian controversy.

the issue arose when the reverend adam sedgwick of cambridge claimed for the cambrianperiod a layer of rock that roderick murchison believed belonged rightly to the silurian. thedispute raged for years and grew extremely heated. “de la beche is a dirty dog,” murchisonwrote to a friend in a typical outburst.

some sense of the strength of feeling can be gained by glancing through the chapter titlesof martin j. s. rudwick’s excellent and somber account of the issue, the great devoniancontroversy. these begin innocuously enough with headings such as “arenas of gentlemanlydebate” and “unraveling the greywacke,” but then proceed on to “the greywacke defendedand attacked,” “reproofs and recriminations,” “the spread of ugly rumors,” “weaverrecants his heresy,” “putting a provincial in his place,” and (in case there was any doubtthat this was war) “murchison opens the rhineland campaign.” the fight was finally settledin 1879 with the simple expedient of coming up with a new period, the ordovician, to beinserted between the two.

because the british were the most active in the early years, british names are predominantin the geological lexicon. devonian is of course from the english county of devon. cambriancomes from the roman name for wales, while ordovician and silurian recall ancient welshtribes, the ordovices and silures. but with the rise of geological prospecting elsewhere,names began to creep in from all over.jurassic refers to the jura mountains on the border offrance and switzerland.permian recalls the former russian province of perm in the uralmountains. forcretaceous (from the latin for “chalk”) we are indebted to a belgian geologistwith the perky name of j. j. d’omalius d’halloy.

originally, geological history was divided into four spans of time: primary, secondary,tertiary, and quaternary. the system was too neat to last, and soon geologists werecontributing additional divisions while eliminating others. primary and secondary fell out ofuse altogether, while quaternary was discarded by some but kept by others. today onlytertiary remains as a common designation everywhere, even though it no longer represents athird period of anything.

lyell, in his principles, introduced additional units known as epochs or series to cover theperiod since the age of the dinosaurs, among them pleistocene (“most recent”), pliocene(“more recent”), miocene (“moderately recent”), and the rather endearingly vague oligocene(“but a little recent”). lyell originally intended to employ “-synchronous” for his endings,giving us such crunchy designations as meiosynchronous and pleiosynchronous. thereverend william whewell, an influential man, objected on etymological grounds andsuggested instead an “-eous” pattern, producing meioneous, pleioneous, and so on. the “-cene” terminations were thus something of a compromise.

nowadays, and speaking very generally, geological time is divided first into four greatchunks known as eras: precambrian, paleozoic (from the greek meaning “old life”),mesozoic (“middle life”), and cenozoic (“recent life”). these four eras are further dividedinto anywhere from a dozen to twenty subgroups, usually called periods though sometimesknown as systems. most of these are also reasonably well known: cretaceous, jurassic,triassic, silurian, and so on.

1then come lyell’s epochs—the pleistocene, miocene, and so on—which apply only to themost recent (but paleontologically busy) sixty-five million years, and finally we have a massof finer subdivisions known as stages or ages. most of these are named, nearly alwaysawkwardly, after places: illinoian, desmoinesian, croixian, kimmeridgian, and so on in likevein. altogether, according to john mcphee, these number in the “tens of dozens.”

fortunately, unless you take up geology as a career, you are unlikely ever to hear any of themagain.

further confusing the matter is that the stages or ages in north america have differentnames from the stages in europe and often only roughly intersect in time. thus the northamerican cincinnatian stage mostly corresponds with the ashgillian stage in europe, plus atiny bit of the slightly earlier caradocian stage.

also, all this changes from textbook to textbook and from person to person, so that someauthorities describe seven recent epochs, while others are content with four. in some books,too, you will find the tertiary and quaternary taken out and replaced by periods of differentlengths called the palaeogene and neogene. others divide the precambrian into two eras, thevery ancient archean and the more recent proterozoic. sometimes too you will see the termphanerozoic used to describe the span encompassing the cenozoic, mesozoic, and paleozoiceras.

moreover, all this applies only to units of time . rocks are divided into quite separate unitsknown as systems, series, and stages. a distinction is also made between late and early(referring to time) and upper and lower (referring to layers of rock). it can all get terriblyconfusing to nonspecialists, but to a geologist these can be matters of passion. “i have seengrown men glow incandescent with rage over this metaphorical millisecond in life’s history,”

the british paleontologist richard fortey has written with regard to a long-running twentieth-century dispute over where the boundary lies between the cambrian and ordovician.

at least today we can bring some sophisticated dating techniques to the table. for most ofthe nineteenth century geologists could draw on nothing more than the most hopefulguesswork. the frustrating position then was that although they could place the various rocksand fossils in order by age, they had no idea how long any of those ages were. whenbuckland speculated on the antiquity of an ichthyosaurus skeleton he could do no better thansuggest that it had lived somewhere between “ten thousand, or more than ten thousand timesten thousand” years earlier.

although there was no reliable way of dating periods, there was no shortage of peoplewilling to try. the most well known early attempt was in 1650 when archbishop jamesussher of the church of ireland made a careful study of the bible and other historical sourcesand concluded, in a hefty tome called annals of the old testament , that the earth had been1there will be no testing here, but if you are ever required to memorize them you might wish to remember johnwilfords helpful advice to think of the eras (precambrian, paleozoic, mesozoic, an( cenozoic) as seasons in ayear and the periods (permian, triassic jurassic, etc.) as the months.

created at midday on october 23, 4004b.c. , an assertion that has amused historians andtextbook writers ever since.

2there is a persistent myth, incidentally—and one propounded in many serious books—thatussher’s views dominated scientific beliefs well into the nineteenth century, and that it waslyell who put everyone straight. stephen jay gould, in time’s arrow, cites as a typicalexample this sentence from a popular book of the 1980s: “until lyell published his book,most thinking people accepted the idea that the earth was young.” in fact, no. as martin j. s.

rudwick puts it, “no geologist of any nationality whose work was taken seriously by othergeologists advocated a timescale confined within the limits of a literalistic exegesis ofgenesis.” even the reverend buckland, as pious a soul as the nineteenth century produced,noted that nowhere did the bible suggest that god made heaven and earth on the first day,but merely “in the beginning.” that beginning, he reasoned, may have lasted “millions uponmillions of years.” everyone agreed that the earth was ancient. the question was simply howancient.

one of the better early attempts at dating the planet came from the ever-reliable edmondhalley, who in 1715 suggested that if you divided the total amount of salt in the world’s seasby the amount added each year, you would get the number of years that the oceans had beenin existence, which would give you a rough idea of earth’s age. the logic was appealing, butunfortunately no one knew how much salt was in the sea or by how much it increased eachyear, which rendered the experiment impracticable.

the first attempt at measurement that could be called remotely scientific was made by thefrenchman georges-louis leclerc, comte de buffon, in the 1770s. it had long been knownthat the earth radiated appreciable amounts of heat—that was apparent to anyone who wentdown a coal mine—but there wasn’t any way of estimating the rate of dissipation. buffon’sexperiment consisted of heating spheres until they glowed white hot and then estimating therate of heat loss by touching them (presumably very lightly at first) as they cooled. from thishe guessed the earth’s age to be somewhere between 75,000 and 168,000 years old. this wasof course a wild underestimate, but a radical notion nonetheless, and buffon found himselfthreatened with excommunication for expressing it. a practical man, he apologized at oncefor his thoughtless heresy, then cheerfully repeated the assertions throughout his subsequentwritings.

by the middle of the nineteenth century most learned people thought the earth was at leasta few million years old, perhaps even some tens of millions of years old, but probably notmore than that. so it came as a surprise when, in 1859 in on the origin of species , charlesdarwin announced that the geological processes that created the weald, an area of southernengland stretching across kent, surrey, and sussex, had taken, by his calculations,306,662,400 years to complete. the assertion was remarkable partly for being so arrestinglyspecific but even more for flying in the face of accepted wisdom about the age of the earth.

3itproved so contentious that darwin withdrew it from the third edition of the book. the2although virtually all books find a space for him, there is a striking variability in the details associated withussher. some books say he made his pronouncement in 1650, others in 1654, still others in 1664. many cite thedate of earths reputed beginning as october 26. at least one book of note spells his name “usher.” the matter isinterestingly surveyed in stephen jay goulds eight little piggies.

3darwin loved an exact number. in a later work, he announced that the number of worms to be found in anaverage acre of english country soil was 53,767.

problem at its heart remained, however. darwin and his geological friends needed the earth tobe old, but no one could figure out a way to make it so.

unfortunately for darwin, and for progress, the question came to the attention of the greatlord kelvin (who, though indubitably great, was then still just plain william thomson; hewouldn’t be elevated to the peerage until 1892, when he was sixty-eight years old and nearingthe end of his career, but i shall follow the convention here of using the name retroactively).

kelvin was one of the most extraordinary figures of the nineteenth century—indeed of anycentury. the german scientist hermann von helmholtz, no intellectual slouch himself, wrotethat kelvin had by far the greatest “intelligence and lucidity, and mobility of thought” of anyman he had ever met. “i felt quite wooden beside him sometimes,” he added, a bit dejectedly.

the sentiment is understandable, for kelvin really was a kind of victorian superman. hewas born in 1824 in belfast, the son of a professor of mathematics at the royal academicalinstitution who soon after transferred to glasgow. there kelvin proved himself such aprodigy that he was admitted to glasgow university at the exceedingly tender age of ten. bythe time he had reached his early twenties, he had studied at institutions in london and paris,graduated from cambridge (where he won the university’s top prizes for rowing andmathematics, and somehow found time to launch a musical society as well), been elected afellow of peterhouse, and written (in french and english) a dozen papers in pure and appliedmathematics of such dazzling originality that he had to publish them anonymously for fear ofembarrassing his superiors. at the age of twenty-two he returned to glasgow university totake up a professorship in natural philosophy, a position he would hold for the next fifty-threeyears.

in the course of a long career (he lived till 1907 and the age of eighty-three), he wrote 661papers, accumulated 69 patents (from which he grew abundantly wealthy), and gained renownin nearly every branch of the physical sciences. among much else, he suggested the methodthat led directly to the invention of refrigeration, devised the scale of absolute temperaturethat still bears his name, invented the boosting devices that allowed telegrams to be sentacross oceans, and made innumerable improvements to shipping and navigation, from theinvention of a popular marine compass to the creation of the first depth sounder. and thosewere merely his practical achievements.

his theoretical work, in electromagnetism, thermodynamics, and the wave theory of light,was equally revolutionary.

4he had really only one flaw and that was an inability to calculatethe correct age of the earth. the question occupied much of the second half of his career, buthe never came anywhere near getting it right. his first effort, in 1862 for an article in apopular magazine called macmillan’s , suggested that the earth was 98 million years old, butcautiously allowed that the figure could be as low as 20 million years or as high as 400million. with remarkable prudence he acknowledged that his calculations could be wrong if4in particular he elaborated the second law of thermodynamics. a discussion of these laws would be a book initself, but i offer here this crisp summation by the chemist p. w atkins, just to provide a sense of them: “thereare four laws. the third of them, the second law, was recognized first; the first, the zeroth law, wasformulated last; the first law was second; the third law might not even be a law in the same sense as theothers.” in briefest terms, the second la\\ states that a little energy is always wasted. you cant have a perpetualmotion device because no matter how efficient, it will always lose energy and eventually run down. the first lawsays that you cant create energy and the third that you cant reduce temperatures to absolute zero; there willalways be some residual warmth. as dennis overbye notes, the three principal laws are sometimes expressedjocularly as (1) you cant win, (2) you cant break even, and (3) you cant get out of the game.

“sources now unknown to us are prepared in the great storehouse of creation”—but it wasclear that he thought that unlikely.

with the passage of time kelvin would become more forthright in his assertions and lesscorrect. he continually revised his estimates downward, from a maximum of 400 millionyears, to 100 million years, to 50 million years, and finally, in 1897, to a mere 24 millionyears. kelvin wasn’t being willful. it was simply that there was nothing in physics that couldexplain how a body the size of the sun could burn continuously for more than a few tens ofmillions of years at most without exhausting its fuel. therefore it followed that the sun and itsplanets were relatively, but inescapably, youthful.

the problem was that nearly all the fossil evidence contradicted this, and suddenly in thenineteenth century there was a lot of fossil evidence.

6    SCIENCE RED IN TOOTH AND CLAW

in 1787, someone in new jersey—exactly who now seems to be forgotten—found anenormous thighbone sticking out of a stream bank at a place called woodbury creek. thebone clearly didn’t belong to any species of creature still alive, certainly not in new jersey.

from what little is known now, it is thought to have belonged to a hadrosaur, a large duck-billed dinosaur. at the time, dinosaurs were unknown.

the bone was sent to dr. caspar wistar, the nation’s leading anatomist, who described it ata meeting of the american philosophical society in philadelphia that autumn. unfortunately,wistar failed completely to recognize the bone’s significance and merely made a few cautiousand uninspired remarks to the effect that it was indeed a whopper. he thus missed the chance,half a century ahead of anyone else, to be the discoverer of dinosaurs. indeed, the boneexcited so little interest that it was put in a storeroom and eventually disappeared altogether.

so the first dinosaur bone ever found was also the first to be lost.

that the bone didn’t attract greater interest is more than a little puzzling, for its appearancecame at a time when america was in a froth of excitement about the remains of large, ancientanimals. the cause of this froth was a strange assertion by the great french naturalist thecomte de buffon—he of the heated spheres from the previous chapter—that living things inthe new world were inferior in nearly every way to those of the old world. america, buffonwrote in his vast and much-esteemed histoire naturelle , was a land where the water wasstagnant, the soil unproductive, and the animals without size or vigor, their constitutionsweakened by the “noxious vapors” that rose from its rotting swamps and sunless forests. insuch an environment even the native indians lacked virility. “they have no beard or bodyhair,” buffon sagely confided, “and no ardor for the female.” their reproductive organs were“small and feeble.”

buffon’s observations found surprisingly eager support among other writers, especiallythose whose conclusions were not complicated by actual familiarity with the country. adutchman named comeille de pauw announced in a popular work called recherchesphilosophiques sur les américains that native american males were not only reproductivelyunimposing, but “so lacking in virility that they had milk in their breasts.” such viewsenjoyed an improbable durability and could be found repeated or echoed in european texts tillnear the end of the nineteenth century.

not surprisingly, such aspersions were indignantly met in america. thomas jeffersonincorporated a furious (and, unless the context is understood, quite bewildering) rebuttal in hisnotes on the state of virginia , and induced his new hampshire friend general john sullivanto send twenty soldiers into the northern woods to find a bull moose to present to buffon asproof of the stature and majesty of american quadrupeds. it took the men two weeks to trackdown a suitable subject. the moose, when shot, unfortunately lacked the imposing horns thatjefferson had specified, but sullivan thoughtfully included a rack of antlers from an elk orstag with the suggestion that these be attached instead. who in france, after all, would know?

meanwhile in philadelphia—wistar’s city—naturalists had begun to assemble the bones ofa giant elephant-like creature known at first as “the great american incognitum” but lateridentified, not quite correctly, as a mammoth. the first of these bones had been discovered ata place called big bone lick in kentucky, but soon others were turning up all over. america,it appeared, had once been the home of a truly substantial creature—one that would surelydisprove buffon’s foolish gallic contentions.

in their keenness to demonstrate the incognitum’s bulk and ferocity, the americannaturalists appear to have become slightly carried away. they overestimated its size by afactor of six and gave it frightening claws, which in fact came from a megalonyx, or giantground sloth, found nearby. rather remarkably, they persuaded themselves that the animalhad enjoyed “the agility and ferocity of the tiger,” and portrayed it in illustrations as pouncingwith feline grace onto prey from boulders. when tusks were discovered, they were forced intothe animal’s head in any number of inventive ways. one restorer screwed the tusks in upsidedown, like the fangs of a saber-toothed cat, which gave it a satisfyingly aggressive aspect.

another arranged the tusks so that they curved backwards on the engaging theory that thecreature had been aquatic and had used them to anchor itself to trees while dozing. the mostpertinent consideration about the incognitum, however, was that it appeared to be extinct—afact that buffon cheerfully seized upon as proof of its incontestably degenerate nature.

buffon died in 1788, but the controversy rolled on. in 1795 a selection of bones made theirway to paris, where they were examined by the rising star of paleontology, the youthful andaristocratic georges cuvier. cuvier was already dazzling people with his genius for takingheaps of disarticulated bones and whipping them into shapely forms. it was said that he coulddescribe the look and nature of an animal from a single tooth or scrap of jaw, and often namethe species and genus into the bargain. realizing that no one in america had thought to writea formal description of the lumbering beast, cuvier did so, and thus became its officialdiscoverer. he called it a mastodon (which means, a touch unexpectedly, “nipple-teeth”).

inspired by the controversy, in 1796 cuvier wrote a landmark paper, note on the species ofliving and fossil elephants, in which he put forward for the first time a formal theory ofextinctions. his belief was that from time to time the earth experienced global catastrophes inwhich groups of creatures were wiped out. for religious people, including cuvier himself, theidea raised uncomfortable implications since it suggested an unaccountable casualness on thepart of providence. to what end would god create species only to wipe them out later? thenotion was contrary to the belief in the great chain of being, which held that the world wascarefully ordered and that every living thing within it had a place and purpose, and always hadand always would. jefferson for one couldn’t abide the thought that whole species would everbe permitted to vanish (or, come to that, to evolve). so when it was put to him that theremight be scientific and political value in sending a party to explore the interior of americabeyond the mississippi he leapt at the idea, hoping the intrepid adventurers would find herdsof healthy mastodons and other outsized creatures grazing on the bounteous plains.

jefferson’s personal secretary and trusted friend meriwether lewis was chosen co-leader andchief naturalist for the expedition. the person selected to advise him on what to look out forwith regard to animals living and deceased was none other than caspar wistar.

in the same year—in fact, the same month—that the aristocratic and celebrated cuvier waspropounding his extinction theories in paris, on the other side of the english channel a rathermore obscure englishman was having an insight into the value of fossils that would also havelasting ramifications. william smith was a young supervisor of construction on the somersetcoal canal. on the evening of january 5, 1796, he was sitting in a coaching inn in somersetwhen he jotted down the notion that would eventually make his reputation. to interpret rocks,there needs to be some means of correlation, a basis on which you can tell that thosecarboniferous rocks from devon are younger than these cambrian rocks from wales. smith’sinsight was to realize that the answer lay with fossils. at every change in rock strata certainspecies of fossils disappeared while others carried on into subsequent levels. by noting which
species appeared in which strata, you could work out the relative ages of rocks wherever theyappeared. drawing on his knowledge as a surveyor, smith began at once to make a map ofbritain’s rock strata, which would be published after many trials in 1815 and would become acornerstone of modern geology. (the story is comprehensively covered in simonwinchester’s popular book the map that changed the world .)unfortunately, having had his insight, smith was curiously uninterested in understandingwhy rocks were laid down in the way they were. “i have left off puzzling about the origin ofstrata and content myself with knowing that it is so,” he recorded. “the whys and whereforescannot come within the province of a mineral surveyor.”

smith’s  revelation  regarding  strata  heightened the moral awkwardness concerningextinctions. to begin with, it confirmed that god had wiped out creatures not occasionally butrepeatedly. this made him seem not so much careless as peculiarly hostile. it also made itinconveniently necessary to explain how some species were wiped out while others continuedunimpeded into succeeding eons. clearly there was more to extinctions than could beaccounted for by a single noachian deluge, as the biblical flood was known. cuvier resolvedthe matter to his own satisfaction by suggesting that genesis applied only to the most recentinundation. god, it appeared, hadn’t wished to distract or alarm moses with news of earlier,irrelevant extinctions.

so by the early years of the nineteenth century, fossils had taken on a certain inescapableimportance, which makes wistar’s failure to see the significance of his dinosaur bone all themore unfortunate. suddenly, in any case, bones were turning up all over. several otheropportunities arose for americans to claim the discovery of dinosaurs but all were wasted. in1806 the lewis and clark expedition passed through the hell creek formation in montana, anarea where fossil hunters would later literally trip over dinosaur bones, and even examinedwhat was clearly a dinosaur bone embedded in rock, but failed to make anything of it. otherbones and fossilized footprints were found in the connecticut river valley of new englandafter a farm boy named plinus moody spied ancient tracks on a rock ledge at south hadley,massachusetts. some of these at least survive—notably the bones of an anchisaurus, whichare in the collection of the peabody museum at yale. found in 1818, they were the firstdinosaur bones to be examined and saved, but unfortunately weren’t recognized for what theywere until 1855. in that same year, 1818, caspar wistar died, but he did gain a certainunexpected immortality when a botanist named thomas nuttall named a delightful climbingshrub after him. some botanical purists still insist on spelling it wistaria .

by this time, however, paleontological momentum had moved to england. in 1812, atlyme regis on the dorset coast, an extraordinary child named mary anning—aged eleven,twelve, or thirteen, depending on whose account you read—found a strange fossilized seamonster, seventeen feet long and now known as the ichthyosaurus, embedded in the steep anddangerous cliffs along the english channel.

it was the start of a remarkable career. anning would spend the next thirty-five yearsgathering fossils, which she sold to visitors. (she is commonly held to be the source for thefamous tongue twister “she sells seashells on the seashore.”) she would also find the firstplesiosaurus, another marine monster, and one of the first and best pterodactyls. though noneof these was technically a dinosaur, that wasn’t terribly relevant at the time since nobody then
knew what a dinosaur was. it was enough to realize that the world had once held creaturesstrikingly unlike anything we might now find.

it wasn’t simply that anning was good at spotting fossils—though she was unrivalled atthat—but that she could extract them with the greatest delicacy and without damage. if youever have the chance to visit the hall of ancient marine reptiles at the natural history museumin london, i urge you to take it for there is no other way to appreciate the scale and beauty ofwhat this young woman achieved working virtually unaided with the most basic tools innearly impossible conditions. the plesiosaur alone took her ten years of patient excavation.

although untrained, anning was also able to provide competent drawings and descriptions forscholars. but even with the advantage of her skills, significant finds were rare and she passedmost of her life in poverty.

it would be hard to think of a more overlooked person in the history of paleontology thanmary anning, but in fact there was one who came painfully close. his name was gideonalgernon mantell and he was a country doctor in sussex.

mantell was a lanky assemblage of shortcomings—he was vain, self-absorbed, priggish,neglectful of his family—but never was there a more devoted amateur paleontologist. he wasalso lucky to have a devoted and observant wife. in 1822, while he was making a house callon a patient in rural sussex, mrs. mantell went for a stroll down a nearby lane and in a pile ofrubble that had been left to fill potholes she found a curious object—a curved brown stone,about the size of a small walnut. knowing her husband’s interest in fossils, and thinking itmight be one, she took it to him. mantell could see at once it was a fossilized tooth, and aftera little study became certain that it was from an animal that was herbivorous, reptilian,extremely large—tens of feet long—and from the cretaceous period. he was right on allcounts, but these were bold conclusions since nothing like it had been seen before or evenimagined.

aware that his finding would entirely upend what was understood about the past, and urgedby his friend the reverend william buckland—he of the gowns and experimental appetite—to proceed with caution, mantell devoted three painstaking years to seeking evidence tosupport his conclusions. he sent the tooth to cuvier in paris for an opinion, but the greatfrenchman dismissed it as being from a hippopotamus. (cuvier later apologized handsomelyfor this uncharacteristic error.) one day while doing research at the hunterian museum inlondon, mantell fell into conversation with a fellow researcher who told him the tooth lookedvery like those of animals he had been studying, south american iguanas. a hastycomparison confirmed the resemblance. and so mantell’s creature became iguanodon , aftera basking tropical lizard to which it was not in any manner related.

mantell prepared a paper for delivery to the royal society. unfortunately it emerged thatanother dinosaur had been found at a quarry in oxfordshire and had just been formallydescribed—by the reverend buckland, the very man who had urged him not to work in haste.

it was the megalosaurus, and the name was actually suggested to buckland by his friend dr.

james parkinson, the would-be radical and eponym for parkinson’s disease. buckland, it maybe recalled, was foremost a geologist, and he showed it with his work on megalosaurus. in hisreport, for the transactions of the geological society of london , he noted that the creature’steeth were not attached directly to the jawbone as in lizards but placed in sockets in themanner of crocodiles. but having noticed this much, buckland failed to realize what it meant:

megalosaurus was an entirely new type of creature. so although his report demonstrated littleacuity or insight, it was still the first published description of a dinosaur, and so to him rather
than the far more deserving mantell goes the credit for the discovery of this ancient line ofbeings.

unaware that disappointment was going to be a continuing feature of his life, mantellcontinued hunting for fossils—he found another giant, the hylaeosaurus, in 1833—andpurchasing others from quarrymen and farmers until he had probably the largest fossilcollection in britain. mantell was an excellent doctor and equally gifted bone hunter, but hewas unable to support both his talents. as his collecting mania grew, he neglected his medicalpractice. soon fossils filled nearly the whole of his house in brighton and consumed much ofhis income. much of the rest went to underwriting the publication of books that few cared toown. illustrations of the geology of sussex , published in 1827, sold only fifty copies and lefthim ￡300 out of pocket—an uncomfortably substantial sum for the times.

in some desperation mantell hit on the idea of turning his house into a museum andcharging admission, then belatedly realized that such a mercenary act would ruin his standingas a gentleman, not to mention as a scientist, and so he allowed people to visit the house forfree. they came in their hundreds, week after week, disrupting both his practice and his homelife. eventually he was forced to sell most of his collection to pay off his debts. soon after, hiswife left him, taking their four children with her.

remarkably, his troubles were only just beginning.

in the district of sydenham in south london, at a place called crystal palace park, therestands a strange and forgotten sight: the world’s first life-sized models of dinosaurs. not manypeople travel there these days, but once this was one of the most popular attractions inlondon—in effect, as richard fortey has noted, the world’s first theme park. quite a lotabout the models is not strictly correct. the iguanodon’s thumb has been placed on its nose,as a kind of spike, and it stands on four sturdy legs, making it look like a rather stout andawkwardly overgrown dog. (in life, the iguanodon did not crouch on all fours, but wasbipedal.) looking at them now you would scarcely guess that these odd and lumbering beastscould cause great rancor and bitterness, but they did. perhaps nothing in natural history hasbeen at the center of fiercer and more enduring hatreds than the line of ancient beasts knownas dinosaurs.

at the time of the dinosaurs’ construction, sydenham was on the edge of london and itsspacious park was considered an ideal place to re-erect the famous crystal palace, the glassand cast-iron structure that had been the centerpiece of the great exhibition of 1851, and fromwhich the new park naturally took its name. the dinosaurs, built of concrete, were a kind ofbonus attraction. on new year’s eve 1853 a famous dinner for twenty-one prominentscientists was held inside the unfinished iguanodon. gideon mantell, the man who had foundand identified the iguanodon, was not among them. the person at the head of the table wasthe greatest star of the young science of paleontology. his name was richard owen and bythis time he had already devoted several productive years to making gideon mantell’s lifehell.

owen had grown up in lancaster, in the north of england, where he had trained as a doctor.

he was a born anatomist and so devoted to his studies that he sometimes illicitly borrowedlimbs, organs, and other parts from cadavers and took them home for leisurely dissection.

once while carrying a sack containing the head of a black african sailor that he had just
removed, owen slipped on a wet cobble and watched in horror as the head bounced awayfrom him down the lane and through the open doorway of a cottage, where it came to rest inthe front parlor. what the occupants had to say upon finding an unattached head rolling to ahalt at their feet can only be imagined. one assumes that they had not formed any terriblyadvanced conclusions when, an instant later, a fraught-looking young man rushed in,wordlessly retrieved the head, and rushed out again.

in 1825, aged just twenty-one, owen moved to london and soon after was engaged by theroyal college of surgeons to help organize their extensive, but disordered, collections ofmedical and anatomical specimens. most of these had been left to the institution by johnhunter, a distinguished surgeon and tireless collector of medical curiosities, but had neverbeen catalogued or organized, largely because the paperwork explaining the significance ofeach had gone missing soon after hunter’s death.

owen swiftly distinguished himself with his powers of organization and deduction. at thesame time he showed himself to be a peerless anatomist with instincts for reconstructionalmost on a par with the great cuvier in paris. he become such an expert on the anatomy ofanimals that he was granted first refusal on any animal that died at the london zoologicalgardens, and these he would invariably have delivered to his house for examination. once hiswife returned home to find a freshly deceased rhinoceros filling the front hallway. he quicklybecame a leading expert on all kinds of animals living and extinct—from platypuses,echidnas, and other newly discovered marsupials to the hapless dodo and the extinct giantbirds called moas that had roamed new zealand until eaten out of existence by the maoris. hewas the first to describe the archaeopteryx after its discovery in bavaria in 1861 and the firstto write a formal epitaph for the dodo. altogether he produced some six hundred anatomicalpapers, a prodigious output.

but it was for his work with dinosaurs that owen is remembered. he coined the termdinosauria in 1841. it means “terrible lizard” and was a curiously inapt name. dinosaurs, aswe now know, weren’t all terrible—some were no bigger than rabbits and probably extremelyretiring—and the one thing they most emphatically were not was lizards, which are actually ofa much older (by thirty million years) lineage. owen was well aware that the creatures werereptilian and had at his disposal a perfectly good greek word, herpeton, but for some reasonchose not to use it. another, more excusable error (given the paucity of specimens at the time)was that dinosaurs constitute not one but two orders of reptiles: the bird-hipped ornithischiansand the lizard-hipped saurischians.

owen was not an attractive person, in appearance or in temperament. a photograph fromhis late middle years shows him as gaunt and sinister, like the villain in a victorianmelodrama, with long, lank hair and bulging eyes—a face to frighten babies. in manner hewas cold and imperious, and he was without scruple in the furtherance of his ambitions. hewas the only person charles darwin was ever known to hate. even owen’s son (who soonafter killed himself) referred to his father’s “lamentable coldness of heart.”

his undoubted gifts as an anatomist allowed him to get away with the most barefaceddishonesties. in 1857, the naturalist t. h. huxley was leafing through a new edition ofchurchill’s medical directory when he noticed that owen was listed as professor ofcomparative anatomy and physiology at the government school of mines, which rathersurprised huxley as that was the position he held. upon inquiring how churchill’s had madesuch an elemental error, he was told that the information had been provided to them by dr.

owen himself. a fellow naturalist named hugh falconer, meanwhile, caught owen taking
credit for one of his discoveries. others accused him of borrowing specimens, then denyinghe had done so. owen even fell into a bitter dispute with the queen’s dentist over the creditfor a theory concerning the physiology of teeth.

he did not hesitate to persecute those whom he disliked. early in his career owen used hisinfluence at the zoological society to blackball a young man named robert grant whose onlycrime was to have shown promise as a fellow anatomist. grant was astonished to discover thathe was suddenly denied access to the anatomical specimens he needed to conduct hisresearch. unable to pursue his work, he sank into an understandably dispirited obscurity.

but no one suffered more from owen’s unkindly attentions than the hapless andincreasingly tragic gideon mantell. after losing his wife, his children, his medical practice,and most of his fossil collection, mantell moved to london. there in 1841—the fateful yearin which owen would achieve his greatest glory for naming and identifying the dinosaurs—mantell was involved in a terrible accident. while crossing clapham common in a carriage,he somehow fell from his seat, grew entangled in the reins, and was dragged at a gallop overrough ground by the panicked horses. the accident left him bent, crippled, and in chronicpain, with a spine damaged beyond repair.

capitalizing  on  mantell’s  enfeebled  state, owen set about systematically expungingmantell’s contributions from the record, renaming species that mantell had named yearsbefore and claiming credit for their discovery for himself. mantell continued to try to dooriginal research but owen used his influence at the royal society to ensure that most of hispapers were rejected. in 1852, unable to bear any more pain or persecution, mantell took hisown life. his deformed spine was removed and sent to the royal college of surgeonswhere—and now here’s an irony for you—it was placed in the care of richard owen, directorof the college’s hunterian museum.

but the insults had not quite finished. soon after mantell’s death an arrestingly uncharitableobituary appeared in the literary gazette. in it mantell was characterized as a mediocreanatomist whose modest contributions to paleontology were limited by a “want of exactknowledge.” the obituary even removed the discovery of the iguanodon from him andcredited it instead to cuvier and owen, among others. though the piece carried no byline, thestyle was owen’s and no one in the world of the natural sciences doubted the authorship.

by this stage, however, owen’s transgressions were beginning to catch up with him. hisundoing began when a committee of the royal society—a committee of which he happenedto be chairman—decided to award him its highest honor, the royal medal, for a paper he hadwritten on an extinct mollusc called the belemnite. “however,” as deborah cadbury notes inher excellent history of the period, terrible lizard, “this piece of work was not quite asoriginal as it appeared.” the belemnite, it turned out, had been discovered four years earlierby an amateur naturalist named chaning pearce, and the discovery had been fully reported ata meeting of the geological society. owen had been at that meeting, but failed to mentionthis when he presented a report of his own to the royal society—in which, not incidentally,he rechristened the creature belemnites owenii in his own honor. although owen was allowedto keep the royal medal, the episode left a permanent tarnish on his reputation, even amonghis few remaining supporters.

eventually huxley managed to do to owen what owen had done to so many others: he hadhim voted off the councils of the zoological and royal societies. as a final insult huxleybecame the new hunterian professor at the royal college of surgeons.

owen would never again do important research, but the latter half of his career was devotedto one unexceptionable pursuit for which we can all be grateful. in 1856 he became head ofthe natural history section of the british museum, in which capacity he became the drivingforce behind the creation of london’s natural history museum. the grand and belovedgothic heap in south kensington, opened in 1880, is almost entirely a testament to his vision.

before owen, museums were designed primarily for the use and edification of the elite, andeven then it was difficult to gain access. in the early days of the british museum, prospectivevisitors had to make a written application and undergo a brief interview to determine if theywere fit to be admitted at all. they then had to return a second time to pick up a ticket—that isassuming they had passed the interview—and finally come back a third time to view themuseum’s treasures. even then they were whisked through in groups and not allowed tolinger. owen’s plan was to welcome everyone, even to the point of encouraging workingmento visit in the evening, and to devote most of the museum’s space to public displays. he evenproposed, very radically, to put informative labels on each display so that people couldappreciate what they were viewing. in this, somewhat unexpectedly, he was opposed by t. h.

huxley, who believed that museums should be primarily research institutes. by making thenatural history museum an institution for everyone, owen transformed our expectations ofwhat museums are for.

still, his altruism in general toward his fellow man did not deflect him from more personalrivalries. one of his last official acts was to lobby against a proposal to erect a statue inmemory of charles darwin. in this he failed—though he did achieve a certain belated,inadvertent triumph. today his statue commands a masterly view from the staircase of themain hall in the natural history museum, while darwin and t. h. huxley are consignedsomewhat obscurely to the museum coffee shop, where they stare gravely over peoplesnacking on cups of tea and jam doughnuts.

it would be reasonable to suppose that richard owen’s petty rivalries marked the low pointof nineteenth-century paleontology, but in fact worse was to come, this time from overseas. inamerica in the closing decades of the century there arose a rivalry even more spectacularlyvenomous, if not quite as destructive. it was between two strange and ruthless men, edwarddrinker cope and othniel charles marsh.

they had much in common. both were spoiled, driven, self-centered, quarrelsome, jealous,mistrustful, and ever unhappy. between them they changed the world of paleontology.

they began as mutual friends and admirers, even naming fossil species after each other,and spent a pleasant week together in 1868. however, something then went wrong betweenthem—nobody is quite sure what—and by the following year they had developed an enmitythat would grow into consuming hatred over the next thirty years. it is probably safe to saythat no two people in the natural sciences have ever despised each other more.

marsh, the elder of the two by eight years, was a retiring and bookish fellow, with a trimbeard and dapper manner, who spent little time in the field and was seldom very good atfinding things when he was there. on a visit to the famous dinosaur fields of como bluff,wyoming, he failed to notice the bones that were, in the words of one historian, “lyingeverywhere like logs.” but he had the means to buy almost anything he wanted. although hecame from a modest background—his father was a farmer in upstate new york—his uncle
was the supremely rich and extraordinarily indulgent financier george peabody. when marshshowed an interest in natural history, peabody had a museum built for him at yale andprovided funds sufficient for marsh to fill it with almost whatever took his fancy.

cope was born more directly into privilege—his father was a rich philadelphiabusinessman—and was by far the more adventurous of the two. in the summer of 1876 inmontana while george armstrong custer and his troops were being cut down at little bighorn, cope was out hunting for bones nearby. when it was pointed out to him that this wasprobably not the most prudent time to be taking treasures from indian lands, cope thought fora minute and decided to press on anyway. he was having too good a season. at one point heran into a party of suspicious crow indians, but he managed to win them over by repeatedlytaking out and replacing his false teeth.

for a decade or so, marsh and cope’s mutual dislike primarily took the form of quietsniping, but in 1877 it erupted into grandiose dimensions. in that year a coloradoschoolteacher named arthur lakes found bones near morrison while out hiking with a friend.

recognizing the bones as coming from a “gigantic saurian,” lakes thoughtfully dispatchedsome samples to both marsh and cope. a delighted cope sent lakes a hundred dollars for histrouble and asked him not to tell anyone of his discovery, especially marsh. confused, lakesnow asked marsh to pass the bones on to cope. marsh did so, but it was an affront that hewould never forget.

it also marked the start of a war between the two that became increasingly bitter,underhand, and often ridiculous. they sometimes stooped to one team’s diggers throwingrocks at the other team’s. cope was caught at one point jimmying open crates that belonged tomarsh. they insulted each other in print and each poured scorn on the other’s results.

seldom—perhaps never—has science been driven forward more swiftly and successfully byanimosity. over the next several years the two men between them increased the number ofknown dinosaur species in america from 9 to almost 150. nearly every dinosaur that theaverage person can name—stegosaurus, brontosaurus, diplodocus, triceratops—was found byone or the other of them.

1unfortunately, they worked in such reckless haste that they oftenfailed to note that a new discovery was something already known. between them theymanaged to “discover” a species calleduintatheres anceps no fewer than twenty-two times. ittook years to sort out some of the classification messes they made. some are not sorted outyet.

of the two, cope’s scientific legacy was much the more substantial. in a breathtakinglyindustrious career, he wrote some 1,400 learned papers and described almost 1,300 newspecies of fossil (of all types, not just dinosaurs)—more than double marsh’s output in bothcases. cope might have done even more, but unfortunately he went into a rather precipitatedescent in his later years. having inherited a fortune in 1875, he invested unwisely in silverand lost everything. he ended up living in a single room in a philadelphia boarding house,surrounded by books, papers, and bones. marsh by contrast finished his days in a splendidmansion in new haven. cope died in 1897, marsh two years later.

in his final years, cope developed one other interesting obsession. it became his earnestwish to be declared the type specimen forhomo sapiens —that is, that his bones would be theofficial set for the human race. normally, the type specimen of a species is the first set of1the notable exception being the tyrannosaurus rex, which was found by barnum brown in 1902.

bones found, but since no first set of homo sapiens bones exists, there was a vacancy, whichcope desired to fill. it was an odd and vain wish, but no one could think of any grounds tooppose it. to that end, cope willed his bones to the wistar institute, a learned society inphiladelphia endowed by the descendants of the seemingly inescapable caspar wistar.

unfortunately, after his bones were prepared and assembled, it was found that they showedsigns of incipient syphilis, hardly a feature one would wish to preserve in the type specimenfor one’s own race. so cope’s petition and his bones were quietly shelved. there is still notype specimen for modern humans.

as for the other players in this drama, owen died in 1892, a few years before cope ormarsh. buckland ended up by losing his mind and finished his days a gibbering wreck in alunatic asylum in clapham, not far from where mantell had suffered his crippling accident.

mantell’s twisted spine remained on display at the hunterian museum for nearly a centurybefore being mercifully obliterated by a german bomb in the blitz. what remained ofmantell’s collection after his death passed on to his children, and much of it was taken to newzealand by his son walter, who emigrated there in 1840. walter became a distinguished kiwi,eventually attaining the office of minister of native affairs. in 1865 he donated the primespecimens from his father’s collection, including the famous iguanodon tooth, to the colonialmuseum (now the museum of new zealand) in wellington, where they have remained eversince. the iguanodon tooth that started it all—arguably the most important tooth inpaleontology—is no longer on display.

of course dinosaur hunting didn’t end with the deaths of the great nineteenth-century fossilhunters. indeed, to a surprising extent it had only just begun. in 1898, the year that fellbetween the deaths of cope and marsh, a trove greater by far than anything found before wasdiscovered—noticed, really—at a place called bone cabin quarry, only a few miles frommarsh’s prime hunting ground at como bluff, wyoming. there, hundreds and hundreds offossil bones were to be found weathering out of the hills. they were so numerous, in fact, thatsomeone had built a cabin out of them—hence the name. in just the first two seasons, 100,000pounds of ancient bones were excavated from the site, and tens of thousands of pounds morecame in each of the half dozen years that followed.

the upshot is that by the turn of the twentieth century, paleontologists had literally tons ofold bones to pick over. the problem was that they still didn’t have any idea how old any ofthese bones were. worse, the agreed ages for the earth couldn’t comfortably support thenumbers of eons and ages and epochs that the past obviously contained. if earth were reallyonly twenty million years old or so, as the great lord kelvin insisted, then whole orders ofancient creatures must have come into being and gone out again practically in the samegeological instant. it just made no sense.

other scientists besides kelvin turned their minds to the problem and came up with resultsthat only deepened the uncertainty. samuel haughton, a respected geologist at trinity collegein dublin, announced an estimated age for the earth of 2,300 million years—way beyondanything anybody else was suggesting. when this was drawn to his attention, he recalculatedusing the same data and put the figure at 153 million years. john joly, also of trinity, decidedto give edmond halley’s ocean salts idea a whirl, but his method was based on so manyfaulty assumptions that he was hopelessly adrift. he calculated that the earth was 89 millionyears old—an age that fit neatly enough with kelvin’s assumptions but unfortunately not withreality.

such was the confusion that by the close of the nineteenth century, depending on whichtext you consulted, you could learn that the number of years that stood between us and thedawn of complex life in the cambrian period was 3 million, 18 million, 600 million, 794million, or 2.4 billion—or some other number within that range. as late as 1910, one of themost respected estimates, by the american george becker, put the earth’s age at perhaps aslittle as 55 million years.

just when matters seemed most intractably confused, along came another extraordinaryfigure with a novel approach. he was a bluff and brilliant new zealand farm boy namedernest rutherford, and he produced pretty well irrefutable evidence that the earth was at leastmany hundreds of millions of years old, probably rather more.

remarkably, his evidence was based on alchemy—natural, spontaneous, scientificallycredible, and wholly non-occult, but alchemy nonetheless. newton, it turned out, had not beenso wrong after all. and exactly how that came to be is of course another story.

7    ELEMENTAL MATTERSCHEMISTRY

as an earnest and respectable science is often said to date from 1661, whenrobert boyle of oxford published the sceptical chymist —the first work to distinguishbetween chemists and alchemists—but it was a slow and often erratic transition. into theeighteenth century scholars could feel oddly comfortable in both camps—like the germanjohann becher, who produced an unexceptionable work on mineralogy called physicasubterranea , but who also was certain that, given the right materials, he could make himselfinvisible.

perhaps nothing better typifies the strange and often accidental nature of chemical sciencein its early days than a discovery made by a german named hennig brand in 1675. brandbecame convinced that gold could somehow be distilled from human urine. (the similarity ofcolor seems to have been a factor in his conclusion.) he assembled fifty buckets of humanurine, which he kept for months in his cellar. by various recondite processes, he converted theurine first into a noxious paste and then into a translucent waxy substance. none of it yieldedgold, of course, but a strange and interesting thing did happen. after a time, the substancebegan to glow. moreover, when exposed to air, it often spontaneously burst into flame.

the commercial potential for the stuff—which soon became known as phosphorus, fromgreek and latin roots meaning “light bearing”—was not lost on eager businesspeople, but thedifficulties of manufacture made it too costly to exploit. an ounce of phosphorus retailed forsix guineas—perhaps five hundred dollars in today’s money—or more than gold.

at first, soldiers were called on to provide the raw material, but such an arrangement washardly conducive to industrial-scale production. in the 1750s a swedish chemist named karl(or carl) scheele devised a way to manufacture phosphorus in bulk without the slop or smellof urine. it was largely because of this mastery of phosphorus that sweden became, andremains, a leading producer of matches.

scheele was both an extraordinary and extraordinarily luckless fellow. a poor pharmacistwith little in the way of advanced apparatus, he discovered eight elements—chlorine, fluorine,manganese, barium, molybdenum, tungsten, nitrogen, and oxygen—and got credit for none ofthem. in every case, his finds were either overlooked or made it into publication aftersomeone else had made the same discovery independently. he also discovered many usefulcompounds, among them ammonia, glycerin, and tannic acid, and was the first to see thecommercial potential of chlorine as a bleach—all breakthroughs that made other peopleextremely wealthy.

scheele’s one notable shortcoming was a curious insistence on tasting a little of everythinghe worked with, including such notoriously disagreeable substances as mercury, prussic acid(another of his discoveries), and hydrocyanic acid—a compound so famously poisonous that150 years later erwin schr?dinger chose it as his toxin of choice in a famous thoughtexperiment (see page 146). scheele’s rashness eventually caught up with him. in 1786, agedjust forty-three, he was found dead at his workbench surrounded by an array of toxicchemicals, any one of which could have accounted for the stunned and terminal look on hisface.

were the world just and swedish-speaking, scheele would have enjoyed universal acclaim.

instead credit has tended to lodge with more celebrated chemists, mostly from the english-speaking world. scheele discovered oxygen in 1772, but for various heartbreakingly complicated reasons could not get his paper published in a timely manner. instead credit wentto joseph priestley, who discovered the same element independently, but latterly, in thesummer of 1774. even more remarkable was scheele’s failure to receive credit for thediscovery of chlorine. nearly all textbooks still attribute chlorine’s discovery to humphrydavy, who did indeed find it, but thirty-six years after scheele had.

although chemistry had come a long way in the century that separated newton and boylefrom scheele and priestley and henry cavendish, it still had a long way to go. right up to theclosing years of the eighteenth century (and in priestley’s case a little beyond) scientistseverywhere searched for, and sometimes believed they had actually found, things that justweren’t there: vitiated airs, dephlogisticated marine acids, phloxes, calxes, terraqueousexhalations, and, above all, phlogiston, the substance that was thought to be the active agentin combustion. somewhere in all this, it was thought, there also resided a mysterious élanvital, the force that brought inanimate objects to life. no one knew where this ethereal essencelay, but two things seemed probable: that you could enliven it with a jolt of electricity (anotion mary shelley exploited to full effect in her novel frankenstein ) and that it existed insome substances but not others, which is why we ended up with two branches of chemistry:

organic (for those substances that were thought to have it) and inorganic (for those that didnot).

someone of insight was needed to thrust chemistry into the modern age, and it was thefrench who provided him. his name was antoine-laurent lavoisier. born in 1743, lavoisierwas a member of the minor nobility (his father had purchased a title for the family). in 1768,he bought a practicing share in a deeply despised institution called the ferme générale (orgeneral farm), which collected taxes and fees on behalf of the government. althoughlavoisier himself was by all accounts mild and fair-minded, the company he worked for wasneither. for one thing, it did not tax the rich but only the poor, and then often arbitrarily. forlavoisier, the appeal of the institution was that it provided him with the wealth to follow hisprincipal devotion, science. at his peak, his personal earnings reached 150,000 livres a year—perhaps $20 million in today’s money.

three years after embarking on this lucrative career path, he married the fourteen-year-olddaughter of one of his bosses. the marriage was a meeting of hearts and minds both. madamelavoisier had an incisive intellect and soon was working productively alongside her husband.

despite the demands of his job and busy social life, they managed to put in five hours ofscience on most days—two in the early morning and three in the evening—as well as thewhole of sunday, which they called their jour de bonheur (day of happiness). somehowlavoisier also found the time to be commissioner of gunpowder, supervise the building of awall around paris to deter smugglers, help found the metric system, and coauthor thehandbook méthode de nomenclature chimique , which became the bible for agreeing on thenames of the elements.

as a leading member of the académie royale des sciences, he was also required to take aninformed and active interest in whatever was topical—hypnotism, prison reform, therespiration of insects, the water supply of paris. it was in such a capacity in 1780 thatlavoisier made some dismissive remarks about a new theory of combustion that had beensubmitted to the academy by a hopeful young scientist. the theory was indeed wrong, but thescientist never forgave him. his name was jean-paul marat.

the one thing lavoisier never did was discover an element. at a time when it seemed as ifalmost anybody with a beaker, a flame, and some interesting powders could discover something new—and when, not incidentally, some two-thirds of the elements were yet to befound—lavoisier failed to uncover a single one. it certainly wasn’t for want of beakers.

lavoisier had thirteen thousand of them in what was, to an almost preposterous degree, thefinest private laboratory in existence.

instead he took the discoveries of others and made sense of them. he threw out phlogistonand mephitic airs. he identified oxygen and hydrogen for what they were and gave them boththeir modern names. in short, he helped to bring rigor, clarity, and method to chemistry.

and his fancy equipment did in fact come in very handy. for years, he and madamelavoisier occupied themselves with extremely exacting studies requiring the finestmeasurements. they determined, for instance, that a rusting object doesn’t lose weight, aseveryone had long assumed, but gains weight—an extraordinary discovery. somehow as itrusted the object was attracting elemental particles from the air. it was the first realization thatmatter can be transformed but not eliminated. if you burned this book now, its matter wouldbe changed to ash and smoke, but the net amount of stuff in the universe would be the same.

this became known as the conservation of mass, and it was a revolutionary concept.

unfortunately, it coincided with another type of revolution—the french one—and for this onelavoisier was entirely on the wrong side.

not only was he a member of the hated ferme générale, but he had enthusiastically builtthe wall that enclosed paris—an edifice so loathed that it was the first thing attacked by therebellious citizens. capitalizing on this, in 1791 marat, now a leading voice in the nationalassembly, denounced lavoisier and suggested that it was well past time for his hanging.

soon afterward the ferme générale was shut down. not long after this marat was murderedin his bath by an aggrieved young woman named charlotte corday, but by this time it was toolate for lavoisier.

in 1793, the reign of terror, already intense, ratcheted up to a higher gear. in octobermarie antoinette was sent to the guillotine. the following month, as lavoisier and his wifewere making tardy plans to slip away to scotland, lavoisier was arrested. in may he andthirty-one fellow farmers-general were brought before the revolutionary tribunal (in acourtroom presided over by a bust of marat). eight were granted acquittals, but lavoisier andthe others were taken directly to the place de la revolution (now the place de la concorde),site of the busiest of french guillotines. lavoisier watched his father-in-law beheaded, thenstepped up and accepted his fate. less than three months later, on july 27, robespierrehimself was dispatched in the same way and in the same place, and the reign of terrorswiftly ended.

a hundred years after his death, a statue of lavoisier was erected in paris and muchadmired until someone pointed out that it looked nothing like him. under questioning thesculptor admitted that he had used the head of the mathematician and philosopher the marquisde condorcet—apparently he had a spare—in the hope that no one would notice or, havingnoticed, would care. in the second regard he was correct. the statue of lavoisier-cum-condorcet was allowed to remain in place for another half century until the second worldwar when, one morning, it was taken away and melted down for scrap.

in the early 1800s there arose in england a fashion for inhaling nitrous oxide, or laughinggas, after it was discovered that its use “was attended by a highly pleasurable thrilling.” for
the next half century it would be the drug of choice for young people. one learned body, theaskesian society, was for a time devoted to little else. theaters put on “laughing gasevenings” where volunteers could refresh themselves with a robust inhalation and thenentertain the audience with their comical staggerings.

it wasn’t until 1846 that anyone got around to finding a practical use for nitrous oxide, asan anesthetic. goodness knows how many tens of thousands of people suffered unnecessaryagonies under the surgeon’s knife because no one thought of the gas’s most obvious practicalapplication.

i mention this to make the point that chemistry, having come so far in the eighteenthcentury, rather lost its bearings in the first decades of the nineteenth, in much the way thatgeology would in the early years of the twentieth. partly it was to do with the limitations ofequipment—there were, for instance, no centrifuges until the second half of the century,severely restricting many kinds of experiments—and partly it was social. chemistry was,generally speaking, a science for businesspeople, for those who worked with coal and potashand dyes, and not gentlemen, who tended to be drawn to geology, natural history, and physics.

(this was slightly less true in continental europe than in britain, but only slightly.) it isperhaps telling that one of the most important observations of the century, brownian motion,which established the active nature of molecules, was made not by a chemist but by a scottishbotanist, robert brown. (what brown noticed, in 1827, was that tiny grains of pollensuspended in water remained indefinitely in motion no matter how long he gave them tosettle. the cause of this perpetual motion—namely the actions of invisible molecules—waslong a mystery.)things might have been worse had it not been for a splendidly improbable character namedcount von rumford, who, despite the grandeur of his title, began life in woburn,massachusetts, in 1753 as plain benjamin thompson. thompson was dashing and ambitious,“handsome in feature and figure,” occasionally courageous and exceedingly bright, butuntroubled by anything so inconveniencing as a scruple. at nineteen he married a rich widowfourteen years his senior, but at the outbreak of revolution in the colonies he unwisely sidedwith the loyalists, for a time spying on their behalf. in the fateful year of 1776, facing arrest“for lukewarmness in the cause of liberty,” he abandoned his wife and child and fled justahead of a mob of anti-royalists armed with buckets of hot tar, bags of feathers, and anearnest desire to adorn him with both.

he decamped first to england and then to germany, where he served as a military advisorto the government of bavaria, so impressing the authorities that in 1791 he was named countvon rumford of the holy roman empire. while in munich, he also designed and laid out thefamous park known as the english garden.

in between these undertakings, he somehow found time to conduct a good deal of solidscience. he became the world’s foremost authority on thermodynamics and the first toelucidate the principles of the convection of fluids and the circulation of ocean currents. healso invented several useful objects, including a drip coffeemaker, thermal underwear, and atype of range still known as the rumford fireplace. in 1805, during a sojourn in france, hewooed and married madame lavoisier, widow of antoine-laurent. the marriage was not asuccess and they soon parted. rumford stayed on in france, where he died, universallyesteemed by all but his former wives, in 1814.

but our purpose in mentioning him here is that in 1799, during a comparatively briefinterlude in london, he founded the royal institution, yet another of the many learnedsocieties that popped into being all over britain in the late eighteenth and early nineteenthcenturies. for a time it was almost the only institution of standing to actively promote theyoung science of chemistry, and that was thanks almost entirely to a brilliant young mannamed humphry davy, who was appointed the institution’s professor of chemistry shortlyafter its inception and rapidly gained fame as an outstanding lecturer and productiveexperimentalist.

soon after taking up his position, davy began to bang out new elements one afteranother—potassium, sodium, magnesium, calcium, strontium, and aluminum or aluminium,depending on which branch of english you favor.

1he discovered so many elements not somuch because he was serially astute as because he developed an ingenious technique ofapplying electricity to a molten substance—electrolysis, as it is known. altogether hediscovered a dozen elements, a fifth of the known total of his day. davy might have done farmore, but unfortunately as a young man he developed an abiding attachment to the buoyantpleasures of nitrous oxide. he grew so attached to the gas that he drew on it (literally) three orfour times a day. eventually, in 1829, it is thought to have killed him.

fortunately more sober types were at work elsewhere. in 1808, a dour quaker named johndalton became the first person to intimate the nature of an atom (progress that will bediscussed more completely a little further on), and in 1811 an italian with the splendidlyoperatic name of lorenzo romano amadeo carlo avogadro, count of quarequa and cerreto,made a discovery that would prove highly significant in the long term—namely, that twoequal volumes of gases of any type, if kept at the same pressure and temperature, will containidentical numbers of molecules.

two things were notable about avogadro’s principle, as it became known. first, itprovided a basis for more accurately measuring the size and weight of atoms. usingavogadro’s mathematics, chemists were eventually able to work out, for instance, that atypical atom had a diameter of 0.00000008 centimeters, which is very little indeed. andsecond, almost no one knew about avogadro’s appealingly simple principle for almost fiftyyears.

2partly this was because avogadro himself was a retiring fellow—he worked alone,corresponded very little with fellow scientists, published few papers, and attended nomeetings—but also it was because there were no meetings to attend and few chemicaljournals in which to publish. this is a fairly extraordinary fact. the industrial revolution was1the confusion over the aluminum/aluminium spelling arose b cause of some uncharacteristic indecisiveness ondavys part. when he first isolated the element in 1808, he called it alumium. for son reason he thought better ofthat and changed it to aluminum four years later. americans dutifully adopted the new term, but mai britishusers disliked aluminum, pointing out that it disrupted the -ium pattern established by sodium, calcium, andstrontium, so they added a vowel and syllable.

2the principle led to the much later adoption of avogadros number, a basic unit of measure in chemistry, whichwas named for avogadro long after his death. it is the number of molecules found in 2.016 grams of hydrogengas (or an equal volume of any other gas). its value is placed at 6.0221367 x 1023, which is an enormously largenumber. chemistry students have long amused themselves by computing just how large a number it is, so i canreport that it is equivalent to the number of popcorn kernels needed to cover the united states to a depth of ninemiles, or cupfuls of water in the pacific ocean, or soft drink cans that would, evenly stacked, cover the earth to adepth of 200 miles. an equivalent number of american pennies would be enough to make every person on eartha dollar trillionaire. it is a big number.

driven in large part by developments in chemistry, and yet as an organized science chemistrybarely existed for decades.

the chemical society of london was not founded until 1841 and didn’t begin to produce aregular journal until 1848, by which time most learned societies in britain—geological,geographical, zoological, horticultural, and linnaean (for naturalists and botanists)—were atleast twenty years old and often much more. the rival institute of chemistry didn’t come intobeing until 1877, a year after the founding of the american chemical society. becausechemistry was so slow to get organized, news of avogadro’s important breakthrough of 1811didn’t begin to become general until the first international chemistry congress, in karlsruhe,in 1860.

because chemists for so long worked in isolation, conventions were slow to emerge. untilwell into the second half of the century, the formula h2o2might mean water to one chemistbut hydrogen peroxide to another. c2h4could signify ethylene or marsh gas. there was hardlya molecule that was uniformly represented everywhere.

chemists also used a bewildering variety of symbols and abbreviations, often self-invented.

sweden’s j. j. berzelius brought a much-needed measure of order to matters by decreeing thatthe elements be abbreviated on the basis of their greek or latin names, which is why theabbreviation for iron is fe (from the latin ferrum ) and that for silver is ag (from the latinargentum ). that so many of the other abbreviations accord with their english names (n fornitrogen, o for oxygen, h for hydrogen, and so on) reflects english’s latinate nature, not itsexalted status. to indicate the number of atoms in a molecule, berzelius employed asuperscript notation, as in h2o. later, for no special reason, the fashion became to render thenumber as subscript: h2o.

despite the occasional tidyings-up, chemistry by the second half of the nineteenth centurywas in something of a mess, which is why everybody was so pleased by the rise toprominence in 1869 of an odd and crazed-looking professor at the university of st. petersburgnamed dmitri ivanovich mendeleyev.

mendeleyev (also sometimes spelled mendeleev or mendeléef) was born in 1834 attobolsk, in the far west of siberia, into a well-educated, reasonably prosperous, and verylarge family—so large, in fact, that history has lost track of exactly how many mendeleyevsthere were: some sources say there were fourteen children, some say seventeen. all agree, atany rate, that dmitri was the youngest. luck was not always with the mendeleyevs. whendmitri was small his father, the headmaster of a local school, went blind and his mother hadto go out to work. clearly an extraordinary woman, she eventually became the manager of asuccessful glass factory. all went well until 1848, when the factory burned down and thefamily was reduced to penury. determined to get her youngest child an education, theindomitable mrs. mendeleyev hitchhiked with young dmitri four thousand miles to st.

petersburg—that’s equivalent to traveling from london to equatorial guinea—and depositedhim at the institute of pedagogy. worn out by her efforts, she died soon after.

mendeleyev dutifully completed his studies and eventually landed a position at the localuniversity. there he was a competent but not terribly outstanding chemist, known more forhis wild hair and beard, which he had trimmed just once a year, than for his gifts in thelaboratory.

however, in 1869, at the age of thirty-five, he began to toy with a way to arrange theelements. at the time, elements were normally grouped in two ways—either by atomic weight(using avogadro’s principle) or by common properties (whether they were metals or gases,for instance). mendeleyev’s breakthrough was to see that the two could be combined in asingle table.

as is often the way in science, the principle had actually been anticipated three yearspreviously by an amateur chemist in england named john newlands. he suggested that whenelements were arranged by weight they appeared to repeat certain properties—in a sense toharmonize—at every eighth place along the scale. slightly unwisely, for this was an ideawhose time had not quite yet come, newlands called it the law of octaves and likened thearrangement to the octaves on a piano keyboard. perhaps there was something in newlands’smanner of presentation, but the idea was considered fundamentally preposterous and widelymocked. at gatherings, droller members of the audience would sometimes ask him if he couldget his elements to play them a little tune. discouraged, newlands gave up pushing the ideaand soon dropped from view altogether.

mendeleyev used a slightly different approach, placing his elements into groups of seven,but employed fundamentally the same principle. suddenly the idea seemed brilliant andwondrously perceptive. because the properties repeated themselves periodically, the inventionbecame known as the periodic table.

mendeleyev was said to have been inspired by the card game known as solitaire in northamerica and patience elsewhere, wherein cards are arranged by suit horizontally and bynumber vertically. using a broadly similar concept, he arranged the elements in horizontalrows called periods and vertical columns called groups. this instantly showed one set ofrelationships when read up and down and another when read from side to side. specifically,the vertical columns put together chemicals that have similar properties. thus copper sits ontop of silver and silver sits on top of gold because of their chemical affinities as metals, whilehelium, neon, and argon are in a column made up of gases. (the actual, formal determinant inthe ordering is something called their electron valences, for which you will have to enroll innight classes if you wish an understanding.) the horizontal rows, meanwhile, arrange thechemicals in ascending order by the number of protons in their nuclei—what is known as theiratomic number.

the structure of atoms and the significance of protons will come in a following chapter, sofor the moment all that is necessary is to appreciate the organizing principle: hydrogen hasjust one proton, and so it has an atomic number of one and comes first on the chart; uraniumhas ninety-two protons, and so it comes near the end and has an atomic number of ninety-two.

in this sense, as philip ball has pointed out, chemistry really is just a matter of counting.

(atomic number, incidentally, is not to be confused with atomic weight, which is the numberof protons plus the number of neutrons in a given element.) there was still a great deal thatwasn’t known or understood. hydrogen is the most common element in the universe, and yetno one would guess as much for another thirty years. helium, the second most abundantelement, had only been found the year before—its existence hadn’t even been suspectedbefore that—and then not on earth but in the sun, where it was found with a spectroscopeduring a solar eclipse, which is why it honors the greek sun god helios. it wouldn’t beisolated until 1895. even so, thanks to mendeleyev’s invention, chemistry was now on a firmfooting.

for most of us, the periodic table is a thing of beauty in the abstract, but for chemists itestablished an immediate orderliness and clarity that can hardly be overstated. “without adoubt, the periodic table of the chemical elements is the most elegant organizational chartever devised,” wrote robert e. krebs in the history and use of our earth’s chemicalelements, and you can find similar sentiments in virtually every history of chemistry in print.

today we have “120 or so” known elements—ninety-two naturally occurring ones plus acouple of dozen that have been created in labs. the actual number is slightly contentiousbecause the heavy, synthesized elements exist for only millionths of seconds and chemistssometimes argue over whether they have really been detected or not. in mendeleyev’s dayjust sixty-three elements were known, but part of his cleverness was to realize that theelements as then known didn’t make a complete picture, that many pieces were missing. histable predicted, with pleasing accuracy, where new elements would slot in when they werefound.

no one knows, incidentally, how high the number of elements might go, though anythingbeyond 168 as an atomic weight is considered “purely speculative,” but what is certain is thatanything that is found will fit neatly into mendeleyev’s great scheme.

the nineteenth century held one last great surprise for chemists. it began in 1896 whenhenri becquerel in paris carelessly left a packet of uranium salts on a wrapped photographicplate in a drawer. when he took the plate out some time later, he was surprised to discoverthat the salts had burned an impression in it, just as if the plate had been exposed to light. thesalts were emitting rays of some sort.

considering the importance of what he had found, becquerel did a very strange thing: heturned the matter over to a graduate student for investigation. fortunately the student was arecent émigré from poland named marie curie. working with her new husband, pierre, curiefound that certain kinds of rocks poured out constant and extraordinary amounts of energy,yet without diminishing in size or changing in any detectable way. what she and her husbandcouldn’t know—what no one could know until einstein explained things the followingdecade—was that the rocks were converting mass into energy in an exceedingly efficient way.

marie curie dubbed the effect “radioactivity.” in the process of their work, the curies alsofound two new elements—polonium, which they named after her native country, and radium.

in 1903 the curies and becquerel were jointly awarded the nobel prize in physics. (mariecurie would win a second prize, in chemistry, in 1911, the only person to win in bothchemistry and physics.)at mcgill university in montreal the young new zealand–born ernest rutherford becameinterested in the new radioactive materials. with a colleague named frederick soddy hediscovered that immense reserves of energy were bound up in these small amounts of matter,and that the radioactive decay of these reserves could account for most of the earth’s warmth.

they also discovered that radioactive elements decayed into other elements—that one dayyou had an atom of uranium, say, and the next you had an atom of lead. this was trulyextraordinary. it was alchemy, pure and simple; no one had ever imagined that such a thingcould happen naturally and spontaneously.

ever the pragmatist, rutherford was the first to see that there could be a valuable practicalapplication in this. he noticed that in any sample of radioactive material, it always took the
same amount of time for half the sample to decay—the celebrated half-life—and that thissteady, reliable rate of decay could be used as a kind of clock. by calculating backwards fromhow much radiation a material had now and how swiftly it was decaying, you could work outits age. he tested a piece of pitchblende, the principal ore of uranium, and found it to be 700million years old—very much older than the age most people were prepared to grant theearth.

in the spring of 1904, rutherford traveled to london to give a lecture at the royalinstitution—the august organization founded by count von rumford only 105 years before,though that powdery and periwigged age now seemed a distant eon compared with the roll-your-sleeves-up robustness of the late victorians. rutherford was there to talk about his newdisintegration theory of radioactivity, as part of which he brought out his piece of pitchblende.

tactfully—for the aging kelvin was present, if not always fully awake—rutherford notedthat kelvin himself had suggested that the discovery of some other source of heat wouldthrow his calculations out. rutherford had found that other source. thanks to radioactivity theearth could be—and self-evidently was—much older than the twenty-four million yearskelvin’s calculations allowed.

kelvin beamed at rutherford’s respectful presentation, but was in fact unmoved. he neveraccepted the revised figures and to his dying day believed his work on the age of the earth hismost astute and important contribution to science—far greater than his work onthermodynamics.

as  with  most  scientific  revolutions,  rutherford’s new findings were not universallyaccepted. john joly of dublin strenuously insisted well into the 1930s that the earth was nomore than eighty-nine million years old, and was stopped only then by his own death. othersbegan to worry that rutherford had now given them too much time. but even withradiometric dating, as decay measurements became known, it would be decades before we gotwithin a billion years or so of earth’s actual age. science was on the right track, but still wayout.

kelvin died in 1907. that year also saw the death of dmitri mendeleyev. like kelvin, hisproductive work was far behind him, but his declining years were notably less serene. as heaged, mendeleyev became increasingly eccentric—he refused to acknowledge the existenceof radiation or the electron or anything else much that was new—and difficult. his finaldecades were spent mostly storming out of labs and lecture halls all across europe. in 1955,element 101 was named mendelevium in his honor. “appropriately,” notes paul strathern, “itis an unstable element.”

radiation, of course, went on and on, literally and in ways nobody expected. in the early1900s pierre curie began to experience clear signs of radiation sickness—notably dull achesin his bones and chronic feelings of malaise—which doubtless would have progressedunpleasantly. we shall never know for certain because in 1906 he was fatally run over by acarriage while crossing a paris street.

marie curie spent the rest of her life working with distinction in the field, helping to foundthe celebrated radium institute of the university of paris in 1914. despite her two nobelprizes, she was never elected to the academy of sciences, in large part because after the deathof pierre she conducted an affair with a married physicist that was sufficiently indiscreet toscandalize even the french—or at least the old men who ran the academy, which is perhapsanother matter.

for a long time it was assumed that anything so miraculously energetic as radioactivitymust be beneficial. for years, manufacturers of toothpaste and laxatives put radioactivethorium in their products, and at least until the late 1920s the glen springs hotel in the fingerlakes region of new york (and doubtless others as well) featured with pride the therapeuticeffects of its “radioactive mineral springs.” radioactivity wasn’t banned in consumerproducts until 1938. by this time it was much too late for madame curie, who died ofleukemia in 1934. radiation, in fact, is so pernicious and long lasting that even now herpapers from the 1890s—even her cookbooks—are too dangerous to handle. her lab books arekept in lead-lined boxes, and those who wish to see them must don protective clothing.

thanks to the devoted and unwittingly high-risk work of the first atomic scientists, by the early years of the twentieth century it was becoming clear that earth was unquestionably venerable, though another half century of science would have to be done before anyone could confidently say quite how venerable. science, meanwhile, was about to get a new age of it sown—the atomic one.