Coming of Age in the Milky Way (14 page)
Read Coming of Age in the Milky Way Online
Authors: Timothy Ferris
Tags: #Science, #Philosophy, #Space and time, #Cosmology, #Science - History, #Astronomy, #Metaphysics, #History
But Galileo’s appetites had evolved from praise to power. Carried away by zeal for his cause, he began insisting that the Copernican cosmology was sufficiently well established scientifically that Scriptures must be conformed to it. Cardinal Robert Bellarmine, Master of Controversial Questions at the Roman College and the greatest theologian of the day, had reservations on this score. He agreed, he wrote in a letter dated April 4, 1615, “that, if there were a real proof that the sun is the center of the universe, that the earth is in the third sphere, and that the sun does not go round the earth but the earth round the sun, then we should have to proceed with great circumspection in explaining passages of Scripture which appear to teach the contrary…. But,” he added, “I do not think there is any such proof since none has been shown to me.”
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In the absence of such a demonstration, Bellarmine cautioned Galileo, to teach Copernicanism as bald fact would be “a very dangerous attitude and one calculated not only to arouse all scholastic philosophers and theologians but also to injure our holy faith by contradicting the Scriptures.”
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Galileo replied that he could prove that Copernicus was right, “but how can I do this, and not be merely wasting my time, when those Peripatetics who must be convinced show themselves incapable of following even the simplest and easiest of arguments?”
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This was pure sophistry. Galileo did not, in fact, have definitive proof of the Copernican theory. What he proffered instead were a series of analogies (the planets go around the sun as Jupiter’s moons go around Jupiter, each is a world just as the moon evidently is a world, etc.) and the phases of Venus, which could be explained as readily by the geocentric model of Tycho as by the heliocentric model of Copernicus.
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.
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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.”
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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.”
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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.”
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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.”
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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.”
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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….
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*
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.
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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.
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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 authority 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.”
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*
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.”
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N
EWTON’S
R
EACH
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
N
ewton 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.)