Читать книгу Water, Ice & Stone - Bill Green - Страница 15
ОглавлениеTHREE
Rutherford’s Den
Matter sings. In its spinning and tumbling, its locked vibrations, its translatory leaps, it sings, but we cannot hear. Beneath the most placid surface—a water drop from Acton Lake, a table at Christchurch, the glacial erratic on the shores of Vanda—there is a ceaseless, sibilant whispering, a kind of delicate rustling and turning, unattended sounds so profligate and spendthrift, so seductive, that if they did not lie forever beyond us, we would be held totally in their thrall.
THREE HOURS OUT OF AUCKLAND the sun rose. The clouds were columns and cliffs in a three-dimensional sky. In time the North Island appeared, sparse in settlement, the bays of Auckland flecked with sails against the brown headlands. We had been more than twenty hours in the air. Had passed from winter into summer, and back again to spring. We had crossed the equator, the dateline near Fiji, had moved ahead an entire day of calendar time. When we landed, there was such relief, such loud applause. It went on for nearly a minute.
We left for Christchurch in early afternoon. The day was clear, and New Zealand lay below, a land of scattered lakes and glaciers, forests and bays. In Christchurch we stayed at the Windsor Hotel, a small bed-and-breakfast in Armagh Street. Old, but open and airy and smelling of spring, it faced onto a large public garden. The curtains of my window billowed in the afternoon breeze and sunlight fell through onto the bed.
I unpacked and went outside: the scent of franjipani, the poinsettias in window boxes against the green lawns. We were in the southern hemisphere now, far away from the sleet and cold of Ohio. We were where water drains clockwise, where it’s mostly ocean, where you can feel the Earth tilt inward toward the sun, leaning you obliquely into the face of its warmth instead of away. I hadn’t been in Christchurch for more than an hour, and I felt as though I had been living there a decade, an expatriate. It was easy: lounging on the park grass in short sleeves; queuing up at the street vendor’s two-wheeled cart for ice cream; sitting on the banks of the Avon River where it wends under poplar and willow, my feet dangling in clear water; sitting in the town square listening to the Wizard, in his starry cape, preach to the pigeons. Even the marble statue of Robert Falcon Scott, in white tunic and polar gloves, looked warm and content.
I did not know how long we would be in New Zealand. Maybe a day, a week. You had to wait until the “Herc,” the LC-130 Hercules, was ready to fly, until the weather at McMurdo was good for landing. Sometimes you’d leave Christchurch, fly for a few hours, then turn around. They never told you why, although there were always rumors. I was anxious to get to the lakes now. Here time moved so slowly. There it would just race, carry me along like a swollen stream.
Our flight had been moved back indefinitely. There were storms over Ross Island: whiteout and seventy-knot winds. Williams Field was closed except for emergencies. Word came that there had been a terrible crash at Siple, out at the recovery site. One of the LC-130s had hit a crevasse, had jackknifed over its nose onto its back. There were rumors of deaths and of many injuries. You could feel a heaviness in the air every time you stopped by the clothing warehouse. People almost whispered when they talked. We were put on alert, advised to stay close to our hotels, to call in every hour, just in case the weather broke.
Morning. There was no plan of action. We fanned out around the city, drank coffee in little shops, ate thin British sandwiches and sausage rolls, wandered the banks of the Avon under its big, shadowy trees. Ripeness. Fullness. Eternal spring. Buses swaying through streets that looked like London. All in the midst of the Pacific. “I could get used to this,” Varner said. “Buy some sheep, settle in, make bulky sweaters.”
To mark time, we decided to go to the formal gardens and to the Ernest Rutherford exhibit, or, as they call it here, “Rutherford’s Den.” Now that we might have a few extra days, I wanted to think about Rutherford, this man from New Zealand; I wanted to think about how he had hollowed out the world, taken the measure of its emptiness; how, like Henry Moore, he had urged us to think of space as much as of substance; how he had turned substance into space. “This is where it all began,” Varner was saying, as he looked into the tiny exhibit room where the tall Rutherford was holding aloft an intricate glass tube. “This is where we really begin to understand.”
There was a day not long ago when matter was thought to be solid and impenetrable, just as it appears. This table to which we have moved in the sunny garden, this table on which I am leaning, supports my coffee cup, my writing pad, my elbow. It supports Varner’s journal, which is lying open and empty before us. Like Sir Arthur Eddington’s famous table,* this one is everything we could hope for: it presses upward against our arms, remains flat and level against the shifts of weight we impose upon it. It is the perfect surface: opaque, rigid, a thing to be counted on. A fine material object.
The English chemist John Dalton would have recognized this table. He would have recognized its properties as mere extensions of the tiny atoms he had been thinking about for years, atoms that were round and massive and hard. There was nothing smaller than Dalton’s atom, and inside there was no space. Like clay spheres in a clay ring, they had no moving parts. As the Greek atmos implied, they were the “uncut,” and, for Dalton, the uncuttable. Solidity, the solidity of this table, was nothing less than one should expect, given the robust atoms of which it is composed.
The world of objects, at its unseen heart, was a collection of microscopic spheres, variously configured bound into aggregates. These spheres had one fundamental and ultimately knowable property, and that was weight. The passion of Daltonian chemistry was the passion for atomic weights.
Atomic weight. We bring that term out from storage, dust it off, recall having heard it somewhere. Chemistry! It is back there with words like mole and chemical formula, words we would rather forget, the intellectual equivalents of spinach and broccoli. I once dreamed of atomic weights: myself on one side of a huge pan balance, metallic cobalt being shoveled from a pickup truck onto the other. All I had to do was count the atoms and I would have the atomic weight of cobalt. I woke up sweating, wondering where I was.
Dalton was far more elegant. While his method could not get you the actual weight of an atom, it could get you its relative weight. It worked like this: Suppose you had some water, say eighteen grams of water, enough to line the bottom of a coffee cup to a few inches’ depth. If you could break that water into its simplest parts—its elements, hydrogen and oxygen—then you could weigh those parts and find out just how much hydrogen combined with how much oxygen to give water. When this was done (and in practice it was done by passing a current through the water, collecting the gaseous hydrogen and oxygen at the electrodes), it always gave the same result: sixteen grams of oxygen at one electrode, two grams of hydrogen at the other. The ratio of the “combining weights” was 16/2 or 8/1.
Did that mean an oxygen atom was eight times heavier than a hydrogen atom? It all depended. It depended on what you thought the formula for water was. If, like Dalton, you thought that water was represented by the formula HO, one atom of hydrogen and one of oxygen, and that you had, therefore, collected equal numbers of oxygen and hydrogen “particles” at your electrodes, it made sense to say, from the combining weights, that an oxygen atom was eight times heavier than a hydrogen atom. But Dalton’s “water” would have made a strange, strange world. Not our world.
Suppose instead water was made. up of two hydrogen atoms for every atom of oxygen, the way that Amadeo Avogadro said it was, in the early nineteenth century. Then what would happen? Now there would be twice as many particles of hydrogen as oxygen, but still the same weights, still sixteen grams of oxygen to two grams of hydrogen. If water is really “H2O,” then oxygen must be sixteen times heavier than hydrogen.
The trick was to know combining weights and formulas so that you could get relative weights. Then you could decide that an oxygen atom weighed sixteen times as much as a hydrogen atom and that carbon weighed twelve times as much. This simple trick, this weighing of atoms, is why we remember John Dalton as the Isaac Newton of chemistry.
Still, those were only relative weights, and it took another fifty-eight years, the congress at Karlsruhe, and the eloquence of Cannizzaro to work out a consistent set of them. It took another fifty years to get absolute weights—how much an atom really weighs in comparison, say, to an autumn leaf. This could only be achieved once Planck and Einstein had determined how many atoms there were in twelve grams of carbon, or one gram of atomic hydrogen, or sixteen grams of atomic oxygen. It turned out to be a lot, and it turned out to be the same in every case: 6.02 X 1023. Avogadro’s number. A mole of particles.
Alas, more broccoli. Yet for the chemist these were the good old days, the days when things were simple, when the atom made sense in a good intuitive way, and when the world it rested on did too. All that changed with Rutherford, and in a way it changed with a single experiment.
By the early part of this century, people knew that Dalton had not quite gotten it right. The atom was a thing of parts, charged parts in fact, fleeting bits and pieces of electricity. J. J. Thomson and Robert Millikan had weighed the electron, defined its charge. Thomson had even proposed a model for how electrons might exist in atoms. What he envisioned was an English pudding, a pudding of positive charge in which were embedded plums of negative electricity—the electrons. The “plum pudding model,” however, mouthwatering as it was to contemplate, was put to the test by Rutherford and found to be wanting.
In 1909, at Cambridge University, Rutherford took a very thin sheet of gold foil and subjected it to a barrage of charged particles. He expected them to rush through the foil, to be bent only slightly from their course. And most of the time that was exactly what happened.
But on occasion, something strange occurred. Some of the particles, moving at half the speed of light, actually rebounded, came back and hit the source, like a tennis ball ricocheting from a wall. Rutherford was stunned. In a letter to a friend he said:
It was quite the most incredible event that has ever happened to me in my life. It was almost as incredible as if you fired a fifteen-inch shell at a piece of tissue paper and it came back and hit you.
What was causing this flimsy sheet of “tissue paper” to withstand the mighty rush of an “artillery shell,” and more, to turn it around and send it back from where it had come? Rutherford thought he knew, and his calculations bore him out. The particles could have been repelled with such force, he reasoned, only if all of the positive charge in the gold atom were compressed into a hard, dense, fiercely compacted point of matter: into a “nucleus.” But where were the electrons? Rutherford argued, and his brilliant student Niels Bohr showed mathematically, that the electrons must be orbiting this nuclear sun like so many tiny planets, like vacant moons. Suddenly it was no longer possible to think of atoms as Daltonian billiard balls, or even as plum puddings. With this single experiment, the atom, upon which the hard back of the physical world rested, became mostly emptiness.
Imagine the rounded dome of a great cathedral on a quiet morning. In its center, on an updraft, is supported a single dust mote, a particle of mica. Between this speck and the great dome there is nothing. Place yourself there on that ceiling and look across the broad enclosure, rose-colored at this hour, toward that glittering point. You are at the distance of the first electron shell, looking inward to the heart of matter itself, whirling and caught in the force of that insignificant nub, the nucleus. And you can barely discern it, barely make it out. What you see, the great fact of your experience, is space pure and simple, empty space, awash over matter like a sea.
That is what solidity—the solidity of tables and chairs, of rocks and mountains and ice—became after Rutherford. An illusion. This table in the garden is no more a plenum than was the latticework of lights that had lain below us in the Hawaiian night. Rather it is a system of shimmering forces, as nuclei rein in the restive electrons, and electrons occupy space the way a turning fan blade does, not by filling it, but by making it impossible for anything else to fill it.
What once seemed full now seems empty. What once seemed so durable now seems evanescent; what once seemed permanent now seems an accidental gathering of particles—gulls on the beach bound for dispersion. For at this level of analysis, this table, matter itself, has too many points of entry, too many microscopic toeholds, too many interstices, too much motion. It can be teased apart, the way manganese is teased by water from basalt; disassembled the way rock is disassembled by wind, layer by layer, atom by atom; the way iron oxides are dissolved and dispersed in the depths of a summer-stratified lake. This table can be turned to smoke, recycled back to carbon dioxide, sent on its way through the wild troposphere, if only enough heat is applied—a small flame will do. Against time and chance this genial gathering of molecules is nothing.
So I lean against the garden table, in the shade of the monkey puzzle tree. As furniture this bit of nothing is entirely adequate. Though now, in the wake of these reflections, it is less familiar.
As it turned out, the physics of Rutherford was only the beginning. Bohr had then to see the possible arrangements of the electron in hydrogen, its planetary paths around the nucleus, its circus leaps and arabesques through the void, the lines of visible light that it cast as a spectrum from eerie tubes in darkened rooms—red, green, blue-green, violet (these and no others). Matter and light linked; the hues of the Swiss schoolteacher Johann Balmer, caught in the net of numbers. Heisenberg, Born, Schroedinger, Dirac, Jordan—the quantum theorists of the “golden age”—had yet to capture the electron as wave, as barn swallow—here, there, everywhere, mere mist of charge. They had yet to give deepened logic to the elements, to the play and recurrence of their themes: the nobility of platinum and gold, the vigor of metallic potassium and cesium, the utter vivacity of fluorine and chlorine.
After two short years, from 1925 to 1927, you could at last understand why hydrogen behaved as it did, its vehement attachments, its liaisons with nearly everything. And the same with oxygen: Now you could rationalize its valence, its self-involvement as a diatomic gas, its undisguised propensity for metals. The red and orange rusts of iron followed exactly from this. And Mendeleyev’s elements, stacked in neat empirical columns, strung in long, sonorous rows, finally sounded, as Mendeleyev had known all along, like a lovely sonata.
So there is a trembling at the heart of matter, at its very core a disquiet. Things oscillate and turn, twist to breaking, collide and sunder, re-form anew. Generation comes from this. And decay. The way a lake rolls and stratifies and rolls again. All that we see is change. The shadow moving on the mountain is the Earth’s moving, the sun’s moving, the explosion of hydrogen against hydrogen far away becoming helium, casting light, spitting photons through vacuums of folded space. Light lands on the mountain, warms the stone, sets it to moving faster deep within itself. You can measure these things, you can feel them against your skin, recon their beginnings as events, as births and deaths by the billion. Warming yourself on a simple rock, you know catastrophe upon catastrophe and you are gladdened by it all, knowing this is the way it has to be, it can be no other. We were given only one world and this is it: reckless, dangerous, sweet, forever in flux. The sun’s death raises the brook in the hills, warms the stone, warms the skin, warms the very soul along its way.
This trembling cannot be stilled, not down at the farthest zero, not on the still life of canvas. Cézanne’s apples spilling on the table, spilling on the cloth. What is still? Not the apples Cézanne faced, brush in hand, waxed skin glowing red, yellow, green, like a spectrum. Not the painting, not now, not ever, not in reproduction. In the wine there is change, in the straw, in the cloth, in the simple fruit. You cannot hold on to it, it is always passing, always gone. Cézanne knew this.
This change has been written into things like a law: electrons on the wing, atoms shaking at their very core. Things build and fall apart. Only the pattern remains, only the name. The mountain is rising, is being worn down, never the same mountain. Look twice, you will not see what you saw before. The flanks, the peaks, the ridges. Even the pattern changes: this is the vision, and physics sings of it. And chemistry. And geology. And biology. Thus, from Rutherford’s physics and what came in its wake the great cycles of the world emerge as necessities. The vision of Ecclesiastes finds its theoretical underpinnings. Beauty and death are everywhere, and everywhere are entwined.
I think it was Varner who reminded me that this journey into the heart of matter, which scientists always associate with the early decades of the century, coincides neatly with the quest for the Pole. Scott’s Discovery Expedition, which came through these very gardens (1901-4), extended the human presence south to 82 degrees latitude during the very years that Planck was probing the discontinuity of physical process and Thomson was sketching the contents of the atom. These were the years of Soddy’s work on radioactivity, of Lenard’s on the photoelectric effect, and of Roentgen’s on X rays. By the time of Scott’s Terra Nova Expedition, Einstein had explained the photoelectric effect, had shown that Brownian motion was the outcome of atomic and molecular events, and had published his epochal papers on special relativity. Bohr was only a year away from his quantum trilogy on the constitution of atoms and molecules.
There was a probing of limits in that age, an effacement of distance, a turning outward and in at the same time that shadowed forth a deeper need. This intellectual passion, this desire to take the measure of the world, to map the territory in which we dwell, shone so brightly that it all but masked the more common motives that were surely there as well. The pure ebullience that seemed to flow out of Thomson’s laboratory, the playfulness of Bohr, with his ping-pong and his animated walks through the Tivoli, the swagger of Rutherford in Manchester claiming of the electron, “why I can see the little beggars there in front of me as plainly as I can see that spoon,” all suggest a grand adventure under way, motivated by a simple need to know.
The warehouse stood in the Antarctic facility near the Christchurch airport. It was a cheerless, functional place. Cement floors, dark walls, cold even in spring, unless the wide doors were thrown open. Before this morning there had been a sense that the journey to the Ice was not yet real; that I would roll over soon, wake up, stare out the window of my own house into the gray Ohio sky, into the leafless redbuds, into my own backyard. But here, now, it became real.
There was a seascape on the wall, a black and white photograph, eight feet by ten, taken by William Curtsinger. In the photograph, a freezing southern ocean heaved, under gray skies, the bitter cold sea blending into low cloud, sky and water dissolving in gray. No ice floes, no pack ice, no research vessels. Only the sea itself. I knew the photograph must have been taken twenty years ago, when Curtsinger worked these latitudes. But it held an instant in time that would play itself over and over again; that at this very moment, as we dressed, was being relived. In this photograph, the southern ocean seemed to brook no intrusion. “Go home to your cities,” said the grim sea. “Go home.” And I once heard of a scientist who, having gazed into this scene for several minutes, thought better of the journey south, handed his clothing back, left the warehouse, and returned to Los Angeles.
Eventually we approached our plane. I climbed through the door into the hold, felt my way along the webbing and canvas seats toward the back. Pipes and wires ran the length of the fuselage, and huge crates, like some dark cordillera, tapered into the tail. I groped my way into a slot between two Navy men and sank into my seat. The plane shook. I took the yellow ear plugs, rolled them into points, and began to insert them into my ears. Mike was yelling at the top of his voice, but I could hardly hear him. “We’re finally going,” he shouted. “Finally. I want to get to the lakes.” I nodded and pushed the plugs in. Moments later we were airborne, above clouds, the tiny windows silver with the morning light.
Six hours out of Christchurch, I walk toward the back of the Herc. I can see my breath. The wool shirt, once close and prickly and hot, is now warm and comfortable. I lean against the cold skin of the aircraft, slouch toward the window, and peer out.
The ice below me is spreading slowly, serenely, poleward. It is only this water molecule: these simple threads of force thrown and repeated over and over, a pattern of matter foreordained by the way that ten electrons weave themselves among three nuclei. The hydrogen of this molecule gropes for the outreaching electrons of that molecule, and the hydrogen of that molecule seeks its opposite charge on the next. If the temperature is low enough and the gropings are not unrequited, ice will form. Project these patterns over thousands of miles, thicken them, give them the hard, illumined edges of sea cliffs; let them gently curve with the Earth’s curve, be unreceptive of light, and you have what is below me in clear view, the glowing white underside of our globe. Greater Antarctica.
Varner is up now. He slowly works his way toward the back, squeezes by a wall of wooden crates. He hands me a crumpled sheet of paper as he passes. On it is a list of flight times. “CINCI to LAX, 4 hours; LAX to HONO, 5 hours; HONO to AUCK, 10 hours; AUCK to CHCH, 1 hour; CHCH to MCM, 8 hours.” “Only two hours more to go,” the sheet reads. “I want to be on the ground. Or the ice. Or whatever it is that’s down there.”
Soon everyone is awake, sitting rigid, hands folded in laps, knotted against the slick fabric of the windpants, the hoods of parkas pulled snugly around faces. We are banking toward Black Island, then away, coming in over McMurdo Sound, making toward the ice runway. The landing is smooth and there is a mild sense of deceleration as the wide skis of the aircraft touch down. The Herc taxies and in five minutes comes to rest; the engines fall silent, the door swings open. The gloom of the fuselage is broken, suddenly shattered by an almost supernal light. We have arrived.
We file through the narrow door. Outside there is silence, except for the wind and the crunch of boots on dry snow. Desert snow. I stagger a little at first, awkward under the weight of my flight bag and thirty pounds of clothing. I squint, trying to adjust my eyes to the glare.
Off to the right I can see Ross Island, and Mount Erebus, a line of steam at a perfect right angle to the cone. There is a cluster of huts to the left, like photographs of old Dakota mining camps. And then this vast whiteness in front of me and behind, and, far away, mountains running off behind mountains behind other mountains into the distance. A continent of mountains lost under the long ages of snow. Thirty million years of snow. I think of my father, what he said about openness and light. How these set you free. I look at Varner, who is turning slowly in circles. I put a hand on his shoulder. He says only, “This isn’t real.” Then he repeats it.
*The astronomer Sir Arthur Eddington begins his book The Nature of the Physical World with a fascinating discussion of the “two tables.” Which of Eddington’s tables is “real”—the table described by modern physics, or the table of our everyday sense experience—has been the subject of considerable philosophical debate ever since.
