When in Rome, Galileo ridiculed the anti-Copernicans at every opportunity, and promised that he would finally reveal his irrefutable proof of the Copernican theory. This turned out to be his erroneous account of the tides—Kepler’s more nearly correct theory having, as usual, been ignored by Galileo. His friends, ecclesiastical and secular alike, warned him not to press the point too far. “This is no place to come to argue about the moon,” the Florentine ambassador cautioned him. Galileo persisted, regardless. “I cannot and must not neglect that assistance which is afforded to me by my conscience as a zealous Christian and Catholic,” he wrote.25
The result of his efforts was that the pope referred the matter to the Holy Office, which declared Copernicanism contrary to Scriptures and put Copernicus’s De Revolutionibus on the Index of forbidden books. Kepler, for once, lost patience. “Some,” he fumed, “through their imprudent behavior, have brought things to such a point that the reading of the work of Copernicus, which remained absolutely free for eighty years, is now prohibited.”26
Enjoined by the Church against espousing Copernicanism, Galileo returned to Florence and there wrote Il Saggiatore (The Assayer) a sarcastic attack on the Jesuit thinker Horatio Grassi. In doing so he added to his growing list of enemies many Jesuits who had been among his allies. (Cardinal Bellarmine, the most powerful of the Jesuits sympathetic to Galileo, had by this time died.)
In 1623, in what seemed a stroke of good fortune, Galileo’s friend and admirer Maffeo Barberini was elected pope. Intelligent, vital, learned, and vain, Barberini had much in common with Galileo. As Galileo’s biographer Arthur Koestler writes, the pope’s “famous statement that he ‘knew better than all the Cardinals put together’ was only equalled by Galileo’s that he alone had discovered everything new in the sky. They both considered themselves supermen and started on a basis of mutual adulation—a type of relationship which, as a rule, comes to a bitter end.”27 Galileo enjoyed six audiences with the new pope, Urban VIII, and was rewarded with lavish gifts and a declaration of “fatherly love” for “this great man, whose fame shines in the heavens.”28 Warmed by the newly risen papal sun, Galileo spent the next four years writing an exposition of the Copernican manifesto, his Dialogue … Concerning the Two Chief World Systems, Ptolemaic and Copernican. Cleared by Church censors, chief among whom now was Galileo’s former pupil Father Niccoló Riccardi, it was published in 1632.
The dialogue form was a device, transparent as Aristotle’s crystalline spheres, through which Galileo could argue for Copernicanism without violating the letter of the papal edict. Two of the conversante, Salviati and Sagredo, are learned gentlemen who sympathize with the Copernican scheme; they serve to speed the argument along on wheels of mutual agreement. Simplicio, the third participant, represents the Scholastics, and is presented as little better than a fool. In a typical passage, Simplicio maintains that “if the terrestrial globe must move in a year around the circumference of a circle—that is, around the zodiac—it is impossible for it at the same time to be in the center of the zodiac. But the earth is at that center, as is proved in many ways by Aristotle, Ptolemy, and others.” To which Salviati, dripping sarcasm, replies: “Very well argued. There can be no doubt that anyone who wants to have the earth move along the circumference of a circle must first prove that it is not at the center of that circle.”29
Galileo’s enemies were quick to point out to the pope that the official cosmology of the Roman Catholic Church had been put into the mouth of the Simplicio the simpleton. It is Simplicio, for instance, who gives voice to a (scientifically accurate, by the way) statement that the pope had ordered inserted into the manuscript, to the effect that Galileo’s theory of the tides does not prove that the earth revolves on its axis. The pope, angered, ordered an investigation, and in August 1632, the Inquisition banned further sales of the Dialogue and ordered all extant copies confiscated.
Galileo responded with the political naivete that was fast becoming his hallmark. He prevailed upon his protector, the grand duke of Tuscany, to send the pope a strongly worded objection to the ban. The pope, who had been elected with the support of Francophile cardinals, was under attack from pro-Spanish factions in the Vatican—a controversy sufficiently heated that he feared assassination—and Galileo’s duke supported Spain. The letter presented the pope with an irresistible opportunity to demonstrate his resolve by quashing an ally of the Francs. The only cost would be his friendship with Galileo, a brilliant but increasingly troublesome old man.
Thus was the clutch released from the wheels of persecution.* Galileo was ordered to appear before the Inquisition in Rome, either voluntarily or to be brought “to the prisons of this supreme tribunal in chains.” He confidently awaited intervention by his friend the pope; it never came. He took refuge for a time in the thought that “everyone will understand that I have been moved to become involved in this task only by zeal for the Holy Church, and to give to its ministers that information which my long studies have brought to me.” The ambassador, whose predecessor had warned him that Rome was “no place to argue about the moon,” quietly acquainted Galileo with the facts of life. There would be no debate concerning the scientific merits of the Copernican system. The issue was obedience. Too late, Galileo realized his position. “He is much afflicted about it,” the ambassador reported back to Florence. “I myself have seen him from yesterday to the present time so dejected that I have feared for his very life.”30
Galileo, now seventy years old, was interrogated at length and threatened with torture. The case against him was sealed by forged “minutes” of his 1616 meeting with Cardinal Bellarmine, reporting that he had been enjoined from holding, teaching, or defending Copernicanism in any way, even as a hypothesis. This was stronger than the warning that had in truth been given him at the time. Left defenseless, Galileo took the only reasonable option available to him, and on June 22, 1633, he recited the prescribed abjuration, from his knees, in the great hall of the Dominican convent of Santa Maria Sopre Minera:
Wishing to remove from the minds of your Eminences and of every true Christian this vehement suspicion justly cast upon me, with sincere heart and unfeigned faith I do abjure, damn, and detest the said errors and heresies, and generally each and every other error, heresy, and sect contrary to the Holy Church; and I do swear for the future that I shall never again speak or assert, orally or in writing, such things as might bring me under similar suspicion….31*
Galileo spent the remaining eight years of his life under house arrest in his villa outside Florence. There he wrote his finest book, the Dialogues Concerning Two New Sciences, a study of motion and inertia. His daughter Sister Marie Celeste, whom he had sent to a convent against her wishes twenty-three years earlier, stayed with him and said the seven daily psalms of penitence ordered by the Holy Office as part of his sentence. He observed the moon and planets through his telescope up until only a few months before he lost his sight, in 1637. “This universe that I have extended a thousand times … has now shrunk to the narrow confines of my own body,” he wrote.33
Milton visited Galileo, and may have gained from him something of the sense of vast spaces that permeates Paradise Lost. Milton’s universe, however, remained earth-centered, and his poem contains a warning against cosmological presumption. In it, a Miltonic angel advises Adam:
Sollicit not thy thoughts with matters hid,
Leave them to God above, him serve and feare;
Of other Creatures, as him pleases best,
Wherever plac’t, let him dispose: joy thou
In what he gives to thee, this Paradise
And thy fair Eve: Heav’n is for thee too high
To know what passes there; be lowlie wise:
Think onely what concernes thee and thy being;
Dream not of other Worlds.34
But that paradise had indeed been lost. Humankind was awakening from a dream of immobility to find itself in a waking fall, its planet plummeting through boundless space. The weight of a
uthority that brought Galileo to his knees succeeded only in halting the growth of science in the Mediterranean. Thereafter, the great advances came in the north countries. The physics of the Copernican universe was to be elucidated by Isaac Newton, born in Woolsthorpe, Lincolnshire, on Christmas Day, 1642, the year of Galileo’s death.
* Ruled not by a feudal aristocracy but by a thriving merchant class, Venice was relatively liberal, innovative, and inquisitive, an excellent place for a freethinker like Galileo. The difference was evident in the way the anatomy classes were conducted: The proscription against dissection, generally obeyed in Pisa, was circumvented at Padua by means of a laboratory table that could be lowered to an underground river, where corpses brought to the university by boat in the dark of night were raised into the hall for dissection in the advanced anatomy class. Proctors kept a lookout, and if the authorities approached the body was lowered away, its place was taken by the usual volume of Hippocrates or Galen, and the lecturer resumed teaching in the conventional fashion.
* He was not unprecedented in making this suggestion. Lucretius in the first century B.C. wrote that “through undisturbed vacuum all bodies must travel at equal speed though impelled by unequal weights,” and some of Galileo’s Renaissance colleagues had proposed the same hypothesis. But none argued for it as convincingly, or investigated the question with greater experimental care, than did Galileo. And, in any event, there is more to science than precedence. As Whitehead remarked, “Everything of importance has been said before by somebody who did not discover it.”11
* Pietro Redoni argues, in his book Galileo: Heretic, that Vatican objections to Galileo may have had less to do with Copernicanism than with his advocacy of atomism and a corpuscular theory of light. Certainly the motives behind Galileo’s persecution were complicated, and are likely to be debated among historians for some time yet to come.
* Three centuries later, in 1980, Pope John Paul II ordered a reexamination of the case of Galileo. Speaking at a ceremony honoring the centenary of Einstein’s birth, the Pope declared that Galileo had “suffered at the hands of men and institutions of the Church,” adding that “research performed in a truly scientific manner can never be in contrast with faith because both profane and religious realities have their origin in the same God.”32
6
NEWTON’S REACH
Watch the stars, and from them learn.
To the Master’s honor all must turn,
each in its track, without a sound,
forever tracing Newton’s ground.*
—Einstein
Nearer the gods no mortal may approach.
—Edmond Halley,
on Newton’s Principia
Newton created a mathematically quantified account of gravitation that embraced terrestrial and celestial phenomena alike. In doing so he demolished the Aristotelian bifurcation of the universe into two realms, one above and one below the moon, and established a physical basis for the Copernican universe. The thoroughness and assurance with which he accomplished this task were such that his theory came to be regarded, for more than two centuries thereafter, as something close to the received word of God. Even today, when Newtonian dynamics is viewed as but a part of the broader canvas painted by Einstein’s relativity, most of us continue to think in Newtonian terms, and Newton’s laws still work well enough to guide spacecraft to the moon and planets. (“I think Isaac Newton is doing most of the driving now,” said astronaut Bill Anders, when asked by his son who was “driving” the Apollo 8 spacecraft carrying him to the moon.)
Yet the man whose explication of the cosmos lives on in a billion minds was himself one of the strangest and most remotely inaccessible individuals who ever lived. When John Maynard Keynes purchased a trunk full of Newton’s papers at auction, he was startled to find that it was full of notes on alchemy, biblical prophecy, and the reconstruction from Hebraic texts of the floor plan of the temple of Jerusalem, which Newton took to be “an emblem of the system of the world.” “Newton was not the first of the age of reason,” a shaken Keynes told a gathering at the Royal Society. “He was the last of the magicians, the last of the Babylonians and Sumerians.”1 Newton was isolated, too, by the singular power of his intellect. Richard Westfall spent twenty years writing a highly perceptive scholarly biography of Newton, yet confessed, in the first paragraph of its preface, that
The more I have studied him, the more Newton has receded from me. It has been my privilege at various times to know a number of brilliant men, men whom I acknowledge without hesitation to be my intellectual superiors. I have never, however, met one against whom I was unwilling to measure myself, so that it seemed reasonable to say that I was half as able as the person in question, or a third or a fourth, but in every case a finite fraction. The end result of my study of Newton has served to convince me that with him there is no measure. He has become for me wholly other, one of the tiny handful of supreme geniuses who have shaped the categories of the human intellect, a man not finally reducible to the criteria by which we comprehend our fellow beings.2
Newton was an only child, the posthumous son of an illiterate yeoman. Born prematurely—so small, his mother used to say, that he could have fit in a quart bottle—he was not expected to survive. His mother, a widow with a farm to manage, soon remarried, and her new husband, the Reverend Barnabus Smith, sent the child off to be raised by his maternal grandmother; there he grew up, only a mile and a half away, within sight of the house where dwelt his loving mother and usurping stepfather. The product of all this— a fatherless birth on Christmas Day, survival against the odds, separation from his mother, and possession of a mind so powerful that he was as much its vassal as its master—was a brooding, simmering boy, sullen and bright and quick to anger. At age twenty Newton compiled a list of his youthful sins; among them were “threatening my father and mother Smith to burne them and the house over them,” “peevishness with my mother,” “striking many,” and “wishing death and hoping it to some.”3
The young Newton was as sensitive to the rhythms of nature as he was indifferent to those of men. As a child he built clocks and sundials and was known for his ability to tell time by the sun, but he habitually forgot to show up for meals, a trait that persisted throughout his life, and he was far too fey to help out reliably on the farm. Sent to gather in livestock, he was found an hour later standing on the bridge leading to the pasture, gazing fixedly into a flowing stream. On another occasion he came home trailing a leader and bridle, not having noticed that the horse he had been leading had slipped away. A sometime practical joker, he alarmed the Lincolnshire populace one summer night by launching a hot-air flying saucer that he constructed by attaching candles to a wooden frame beneath a wax paper canopy.* He seldom studied and customarily fell behind at grammar school, but applied himself at the end of each term and surpassed his classmates on final examinations, a habit that did little to enhance his popularity. A contemporary of Newton’s reported that when the boy left for Cambridge, the servants at Woolsthorpe Manor “rejoiced at parting with him, declaring, he was fit for nothing but the ’Versity.”4
At college he filled his lonely life with books. “Amicus Plato amicus Aristoteles magis arnica Veritas,’” he wrote in his student notebook—“Plato is my friend, Aristotle is my friend, but my greatest friend is truth.”5 He seems to have made the acquaintance of only one of his fellow students, John Wickins, who found him walking in the gardens “solitary and dejected” and took pity on him. Newton’s studies, like those of many a clever undergraduate, were eclectic—he looked into everything from universal languages to perpetual motion machines—but he pursued them with a unique intensity. Nothing, least of all his personal comfort, could deter him when he was on to a question of interest: To investigate the anatomy of the eye he stuck a bodkin “betwixt my eye and the bone as near to the backside of my eye as I could,” and he once stared at the sun for so long that it took days of recuperation in a dark room before his vision returned to normal.
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For a time he drew inspiration from the books of Rene Descartes, a kindred spirit. Descartes like Newton had been a frail child, brought up by his grandmother, and both men were seized by an all-embracing vision while in their early twenties: Newton’s epiphany was universal gravitation; Descartes’s involved nothing less than a science of all human knowledge. Descartes died in 1650, more than a decade before Newton arrived at Cambridge, but his works were very much alive among the “brisk part” of the faculty—those whose intellectual horizons were not bounded by Aristotle’s.*
But if Newton learned a great deal from Descartes’s Principia Philosophiae—which included, among many other things, an assertion that inertia involves resistance to changes in motion and not just to motion itself—he was always happiest in contention, and Descartes’s philosophy promoted in him an equal and opposite reaction. Descartes’s disapproval of atomism helped turn Newton into a confirmed atomist. Descartes’s vortex theory of the solar system became the foil for Newton’s demonstration that vortices could not account for Kepler’s laws of planetary motion. Descartes’s emphasis on depicting motion algebraically encouraged Newton to develop a dynamics written in terms of algebra’s alternative, geometry; as this was not yet mathematically feasible, Newton found it necessary to invent a new branch of mathematics, the calculus. Infinitesimal calculus set geometry in motion: The parabolas and hyperbolas Newton drew on the page could be analyzed as the product of a moving point, like the tip of the stick with which Archimedes drew figures in the sand. As Newton put it, “Lines are described, and thereby generated not by the opposition of parts, but by the continued motion of points.” Here the unbending Newton danced.
Coming of Age in the Milky Way Page 10
