The Clockwork Universe Read online

  Galileo continued to improve his design and soon produced a telescope able to magnify twenty times, twice as powerful as his first model. He could now be certain that the new stars that had appeared in 1572 and 1604 were the merest prelude, a two-note introduction to a visual symphony.

  His own excitement fully matched that of the ecstatic senators in San Marco’s belltower. The “absolute novelty” of his discoveries, Galileo wrote, filled him with “incredible delight.” He marveled at the sight of “stars in myriads, which have never been seen before, and which surpass the old, previously known stars in number more than ten times.” The moon, the perfect disc of a thousand poets’ odes, “does not possess a smooth and polished surface but one rough and uneven and just like the face of the Earth itself, everywhere full of vast protuberances, deep chasms, and sinuosities.”

  The Milky Way was not some kind of cosmic fog reflecting light from the sun or moon, as had long been speculated. A glance through the telescope would at once put an end to all “wordy disputes upon this subject,” Galileo boasted, and would leave no doubt that “the Galaxy is nothing else but a mass of innumerable stars planted together in clusters . . . many of them tolerably large and extremely bright, and the number of small ones quite beyond determination.”

  Yet another discovery was the most important of all, guaranteed to “excite the greatest astonishment by far.” But even for Galileo the astonishment was slow in dawning. He had aimed his telescope at Jupiter and spotted several bright objects near the planet. The next day they were still there, but they had rearranged themselves. A few days later, another rearrangement. Some days there were four objects; some days only two or three. What could it mean?

  Jupiter and nearby mysterious objects, as seen by Galileo

  The answer, Galileo came to see, was that four objects were in orbit around Jupiter. “I have discovered four planets, neither known nor observed by any one of the astronomers before my time,” Galileo crowed. (He hurried to name the moons in honor of Cosimo de’ Medici, Grand Duke of Tuscany, who swallowed the bait with gusto.) Here was a planetary system in miniature, and not a diagram or a mathematical hypothesis but an observable reality. Jupiter’s moons were mini-Earths moving in orbit around a central body. Why could not the Earth itself be in orbit around a huge central body? And if the Earth, why not the other planets, too?

  These were exhilarating, disorienting discoveries. The unsuspected vistas revealed by the telescope inspired a fair number of seventeenth-century thinkers to rejoice at this proof that God’s creation was truly without bounds. It was only fitting that an infinite God should have created an infinite universe. What could be “more splendid, glorious, and magnificent than for God to have made the universe commensurate with his own immensity?” asked the Royal Society’s Joseph Glanvill.

  The gates to the cosmos had been thrown open, and optimists ran through and turned cartwheels in the vastness. “When the heavens were a little blue arch stuck with stars, methought the universe was too strait and close,” exulted the French writer Bernard de Fontenelle, in an immensely popular account of the new doctrines called On the Plurality of Worlds. “I was almost stifled for want of air; but now it is enlarged in height and breadth and a thousand vortexes taken in. I begin to breathe with more freedom, and I think the universe to be incomparably more magnificent than it was before.”24

  But the endless expanses that beckoned so invitingly to some induced a kind of trembling agoraphobia in others. Pascal spoke for all who found themselves horrified by a vision of the planets as specks of dust adrift in a black immensity. “The eternal silence of these infinite spaces frightens me,” he observed, and he seemed to view humankind on its lonely voyage as akin to a ship’s crew adrift in an endless sea. “What is a man in the midst of infinity?” Pascal asked.

  Decades before, Copernicus’s pushing of the Earth off center stage had inspired similar questions and similar fears, but among a smaller audience. Galileo had far more impact. Anyone could look through a telescope, while almost no one could follow a mathematical argument. But whether Copernicus or Galileo took the role of narrator, the story was the same. The Earth was not the center of the universe but a run-of-the-mill planet in a random corner of the cosmos.

  This stripping away of Earth’s special status is always cited as a great assault on human pride. Freud famously contended, for example, that in the course of modern history three thinkers had dealt enormous blows to humankind’s self-esteem. The three were Copernicus, Darwin, and Freud himself. Darwin had proved that humans are animals, and Freud that we are blind to our own motivations. But the first body blow had come from Copernicus, who had displaced mankind from his place of honor.

  Freud had a key piece of the story almost exactly backward. Before Copernicus and Galileo, humans had believed that they lived at the center of the universe, but in their minds the center was a shameful, degraded place, not an exalted one. The Earth was lowly in every sense, at the furthest possible remove from the heavens. Man occupied “the filth and mire of the world,” wrote Montaigne, “the worst, lowest, most lifeless part of the universe, the bottom story of the house.”

  In the cosmic geography of the day, heaven and hell were actual places. Hell was not consigned to some vague location “below” but sat deep inside the Earth with its center directly beneath Jerusalem. The Earth was the center of the universe, and hell was the center of the center. Galileo’s adversary Cardinal Bellarmine spelled out why that was so. “The place of devils and wicked damned men should be as far as possible from the place where angels and blessed men will be forever. The abode of the blessed (as our adversaries agree) is Heaven, and no place is further removed from Heaven than the center of the earth.”

  Mankind had always occupied a conspicuous place in the universe, in other words, but it was a dangerous and exposed position rather than a seat of honor. Theologians through the ages had thought well of that arrangement precisely because it did not puff up human pride. Humility was a virtue, they taught, and a home set amid “filth and mire” was nearly certain to have humble occupants.

  In a sense, Copernicus had done mankind a favor. By moving the Earth to a less central locale, he had moved humankind farther from harm’s way. For religious thinkers, ironically, this was yet another reason to object to the new doctrine. Theologians found themselves contemplating a riddle—how to keep humanity in its place when its place had moved?

  In time, they would come up with an answer. They would seize on a different aspect of the new astronomy, the vast expansion in the size of the universe. If the universe was bigger, then man was smaller. For theologians in search of a way to reconcile themselves to science’s new teachings, a doctrine that seemed to belittle mankind was welcome news.

  Chapter Eighteen

  Flies as Big as a Lamb

  The microscope came along a bit later than the telescope, but its discovery produced just as much amazement. Here, too, were new worlds, and this time teeming with life! The greatest explorer of these new kingdoms was an unlikely conquistador, a Dutch merchant named Antonie van Leeuwenhoek. He seems to have begun tinkering with lenses with no grander ambition than to check for defects in swatches of cloth.

  Leeuwenhoek quickly moved beyond fabric samples. Peering through microscopes he built himself—more like magnifying glasses than what we think of as microscopes—he witnessed scenes that no one else had ever imagined. In a frenzy of excitement, he dashed off letters to the Royal Society, hundreds altogether, describing the “secret world” he had found. He thrilled at the living creatures in a drop of water scooped from a puddle and then found he did not even have to venture outdoors to find teeming, complex life. He put his own saliva under the microscope and “saw, with great wonder, that in the said matter there were many very little living animalcules, very prettily a-moving. The biggest sort had a very strong and swift motion, and shot through the spittle like a pike does through the water.”

  Hooke had been experimenting with microsco
pes of his own design for years. Leeuwenhoek’s microscopes yielded clearer images, but on November 15, 1677, Hooke reported that he, too, had seen a great number of “exceedingly small animals” swimming in a drop of water. And he had witnesses. Hooke rattled off a list: “Mr. Henshaw, Sir Christopher Wren, Sir John Hoskyns, Sir Jonas Moore, Dr. Mapletoft, Mr. Hill, Dr. Croone, Dr. Grew, Mr. Aubrey, and diverse others.” The roll call of names highlights just how shocking these findings were. The microscope was so unfamiliar, and the prospect of a tiny, living, hitherto invisible world so astonishing, that even an eminent investigator like Hooke needed allies. It would be as if, in our day, Stephen Hawking turned a new sort of telescope to the heavens and saw UFOs flying in formation. Before he told the world, Hawking might coax other eminent figures to look for themselves.

  But Hooke and the rest of the Royal Society could not catch Leeuwenhoek. Endlessly patient, omnivorously curious, and absurdly sharp-eyed, he racked up discovery after discovery.25 Sooner or later, everything—pond water, blood, plaque from his teeth—found its way to his microscope slides. Leeuwenhoek jumped up from his bed one night, “immediately after ejaculation before six beats of the pulse had intervened,” and raced to his microscope. There he became the first person ever to see sperm cells. “More than a thousand were moving about in an amount of material the size of a grain of sand,” he wrote in amazement, and “they were furnished with a thin tail, about five or six times as long as the body . . . and moved forward owing to the motion of their tails like that of a snake or an eel swimming in water.”26 Leeuwenhoek hastened to assure the Royal Society that he had obtained his sample “after conjugal coitus” (rather than “by sinfully defiling myself”), but he did not discuss whether Mrs. Leeuwenhoek shared his fascination with scientific observation.

  No matter. Others did. Even Charles II delighted in peering through microscopes and witnessing life in miniature. “His Majesty seeing the little animals, contemplated them in astonishment and mentioned my name with great respect,” Leeuwenhoek wrote proudly. This was a development almost as striking as Leeuwenhoek’s findings themselves. In the new world of science, a merchant who had never attended a university and knew only Dutch, not Latin, could make discoveries that commanded the attention of a king.

  Both the microscope and the telescope fascinated the seventeenth century’s intelligentsia, not just its scientists. The telescope tended to produce unwelcome musings on man’s puniness, as we have seen, but the picture of worlds within worlds revealed by the microscope did not trouble most people. Pascal was an exception. The endless descent into microworlds—“limbs with joints, veins in these limbs, blood in these veins, humors in this blood, globules in these humors, gases in these globules”—left him queasy and afraid. Many a ten-year-old has delighted in an imaginary outward zoom that plays Pascal’s voyage in reverse: I live at 10 Glendale Road in the town of Marblehead in the county of Essex in the state of Massachusetts in the United States of America on the planet Earth in the Milky Way galaxy. Pascal’s inward journey shared the same rhythm, but the dread in his tone stood the child’s exhilaration on its head.

  Most people felt more fascination than fright, perhaps simply because we tend to feel powerful in proportion to our size. In any case, both telescope and microscope strengthened the case for God as designer. The ordinary world had already provided countless examples of God’s craftsmanship. “Were men and beast made by fortuitous jumblings of atoms,” Newton wrote contemptuously, “there would be many parts useless in them—here a lump of flesh, there a member too much.” Now the microscope showed that God had done meticulous work even in secret realms that man had never known. Unlike those furniture makers, say, who lavished all their care on the front of their bureaus and desks but neglected surfaces destined to stay hidden, God had made every detail perfect.

  The heavens declared the glory of God, and so did fleas and flies and feathers. Man-made objects looked shoddy in comparison. Hooke examined the tip of a needle under a microscope, to test the aptness of the expression “as sharp as a Needle.” He found not a perfect, polished surface but “large Hollows and Roughnesses, like those eaten in an Iron Bar by Rust and Length of Time.” A printed dot on the page of a book told the same story. To the naked eye it looked “perfectly black and round,” wrote Hooke, “but through the Magnifier it seemed grey, and quite irregular, like a great Splatch of London Dirt.”

  No features of the natural world were too humble to inspire rapt study. In some of the earliest experiments with microscopes, Galileo had tinkered with various designs. His astonishment reaches us across a gap four centuries wide. Galileo had seen “flies which look as big as a lamb,” he told a French visitor, “and are covered all over with hair, and have very pointed nails by means of which they keep themselves up and walk on glass, although hanging feet upwards.”

  Many of the objects that came in for close examination were even less grand than houseflies. In April 1669 Hooke and the other members of the Royal Society gazed intently at a bit of fat and then at a moldy smear of bookbinder’s paste, “which was found to have a fine moss growing on it.” One early scientist who studied plants under the microscope marveled that “one who walks about with the meanest stick holds a piece of nature’s handicraft which far surpasses the most elaborate . . . needlework in the world.”

  Robert Hooke’s drawing of a fly’s meticulously “designed” eyes

  Hooke published a lavish book called Micrographia that featured such stunning illustrations (by Hooke himself) as a twelve-by-eighteen-inch foldout engraving of a flea. The creature was, Hooke noted admiringly, “adorn’d with a curiously polish’d suit of sable Armour, neatly jointed.” Another oversize illustration showed a fly’s eyes, with some fourteen thousand facets or “pearls.” Hooke went out of his way to justify lavishing attention on so lowly an insect. “There may be as much curiosity of contrivance and structure in every one of these Pearls, as in the eye of a Whale or Elephant,” he wrote, and he noted that in any case God was surely up to such a task. “As one day and a thousand years are the same with him, so may one eye and ten thousand.”

  Both telescope and microscope had opened up new worlds. The new vistas served to reinforce the belief that on every scale the universe was a flawless, harmonious, and unimaginably complex mechanism. God was a sculptor who could shape stars and planets and a craftsman with a delicacy of touch to shame the finest jeweler.

  Chapter Nineteen

  From Earthworms to Angels

  If the thinkers of the seventeenth century had been content to see God as a superbly talented artist and craftsman, their homage might have taken a different form. Instead they looked at the marvelous sights revealed by the telescope and microscope and found new support for their favorite doctrine, that God was a mathematician.

  They believed it already, thanks largely to their discoveries about the geometry of the cosmos, but they saw the new evidence as proving the case beyond the least possible doubt. In part this was because of the new sights themselves. Seen through the microscope, the least imposing objects revealed a geometer’s shaping hand. One early scientist wrote an astonished hymn to grains of salt, which turned out to be “Cubes, Rhombs, Pyramids, Pentagons, Hexagons, Octagons” rendered “with a greater Mathematical Exactness than the most skilful Hand could draw them.”

  But the renewed emphasis on God-the-mathematician came mostly by way of a different, stranger path. One of the seventeenth century’s most deeply held beliefs had to do with the so-called great chain of being. The central idea was that all the objects that had ever been created—grains of sand, chunks of gold, earthworms, lions, human beings, devils, angels—occupied a particular rank in a great chain that extended from the lowest of the low to the hem of God’s garment. Nearby ranks blended almost insensibly into one another. Some fish had wings and flew into the air; some birds swam in the sea.

  It was a fantastically elaborate system, though it strikes modern ears as more akin to a magical realist fantasy tha
n a guide to everyday life. Purely by reasoning, the intellectuals of the seventeenth century believed, they could draw irrefutable conclusions about the makeup of the world. Angels, for example, were as real as oak trees. Since God himself had fashioned the great chain, it was necessarily perfect and could not be missing any links. So, just as there were countless creatures reaching downward from humans to the beasts, there had to be countless steps leading upward from humans to God. QED.

  That made for a lot of angels. “We must believe that the angels are there in marvelous and inconceivable numbers,” one scholar wrote, “because the honor of a king consists in the great crowd of his vassals, while his disgrace or shame consists in their paucity. Thousands of thousands wait on the divine majesty and tenfold hundreds of millions join in his worship.”

  Each link had its proper place in the hierarchy, king above noble above commoner, husband above wife above child, dog above cat, worm above oyster. The lion was king of beasts, but every domain had a “king”: the eagle among birds, the rose among flowers, the monarch among humans, the sun among the stars. The various kingdoms themselves had specific ranks, too, some lower and some higher—stones, which are lifeless, ranked lower than plants, which ranked lower than shellfish, which ranked lower than mammals, which ranked lower than angels, with innumerable other kingdoms filling all the ranks in between.

  In a hierarchical world, the doctrine had enormous intuitive appeal. Those well placed in the pecking order embraced it, unsurprisingly, but even those stuck far from the top made a virtue of “knowing one’s place.” Almost without exception, scholars and intellectuals endorsed the doctrine of the all-embracing, immutable great chain. To say that things might be different was to suggest that they could be better. This struck nearly everyone as both misguided—to attack the natural order was to shake one’s fist at the tide—and blasphemous. Since God was an infinitely powerful creator, the world necessarily contained all possible things arranged in the best possible way. Otherwise He might have done more or done better, and who would presume to venture such a criticism?