What was wrong there? Nobody knows. I think that they lacked that great dynamic image which so moved the Old World – the wheel. The wheel was only a toy in the New World. But in the Old World it was the greatest image of poetry and science; everything was founded on it. This sense of the heavens moving round their hub inspired Christopher Columbus when he set sail in 1492, and the hub was the round earth. He had it from the Greeks, who believed that the stars were fixed on spheres which made music as they turned. Wheels within wheels. That was the system of Ptolemy that had worked for over a thousand years.
More than a hundred years before Christopher Columbus set sail, the Old World had been able to make a superb clockwork of the starry heavens. It was made by Giovanni de Dondi in Padua in about 1350. It took him sixteen years, and it is sad that the original has not survived. Happily, it has been possible to build a duplicate from his working drawings, and the Smithsonian Institution in Washington houses the marvellous model of classical astronomy that Giovanni de Dondi designed.
But more than the mechanical marvel is the intellectual conception, which comes from Aristotle and Ptolemy and the Greeks. De Dondi’s clock is their view of the planets as seen from the earth. From the earth there are seven planets – or so the ancients thought, since they counted the sun also as a planet of the earth. So the clock has seven faces or dials, and on each face rides a planet. The path of the planet on its dial is (approximately) the path that we see from the earth – the clock is about as accurate as observation was when it was made. Where the path looks circular from the earth, it is circular on its dial; that was easy. But where the path of a planet loops back on itself when seen from the earth, de Dondi has a mechanical combination of wheels which copies the epicycles (that is, the rolling of circles on circles) by which Ptolemy had described it.
First, then, the Sun: a circular path, as it seemed then. The next dial shows Mars: its motion is running on a clockwork wheel inside a wheel. Then Jupiter: more complex wheels within wheels. Next Saturn: wheels within wheels. Then we come to the Moon – her dial is simple, because she truly is a planet of the earth, and her path is shown as circular. Lastly we come to the dials for the two planets that lie between us and the Sun; that is, to Mercury, and finally to Venus. And again the same picture: the wheel that carries Venus turns inside a larger, hypothetical wheel.
It is a marvellous intellectual conception; very complex – but that only makes it more marvellous that in AD 150, not long after the birth of Christ, the Greeks should have been able to conceive and put into mathematics this superb construction. Then what is wrong with it? One thing only: that there are seven dials for the heavens – and the heavens must have one machinery, not seven. But that machinery was not found until Copernicus put the sun at the centre of the heavens in 1543.
Nicolaus Copernicus was a distinguished churchman and a humanist intellectual from Poland, born in 1473. He had studied law and medicine in Italy; he advised his government on currency reform; and the Pope asked his help on calendar reform. For at least twenty years of his life, roughly, he devoted himself to the modern proposition that nature must be simple. Why were the paths of the planets so complicated? Because, he decided, we look at them from the place where we happen to be standing, the earth. Like the pioneers of perspective, Copernicus asked, Why not look at them from another place? There were good Renaissance reasons, emotional rather than intellectual reasons, that made him choose the golden sun as the other place.
Copernicus put the sun at the centre of the heavens in 1543.
Two pages from the ‘De Revolutionibus Orbium Coelestium’.
In the middle of all sits the Sun enthroned. In this most beautiful temple, could we place this luminary in any better position from which he can illuminate the whole at once? He is rightly called the Lamp, the Mind, the Ruler of the Universe: Hermes Trismegistus names him the Visible God, Sophocles’ Electra calls him the All-Seeing. So the Sun sits as upon a royal throne, ruling his children, the planets which circle round him.
We know that Copernicus had thought of putting the sun at the centre of the planetary system for a long time. He may have written the first tentative and non-mathematical sketch of his scheme before he was forty. However, this was not a proposal to be made lightly in an age of religious upheaval. By 1543, near seventy, Copernicus had finally braced himself to publish his mathematical description of the heavens, what he called De Revolutionibus Orbium Coelestium, The Revolution of the Heavenly Orbs, as a single system moving round the sun. (The word ‘revolution’ has an overtone now which is not astronomical, and that is not an accident. It comes from this time and this topic.) Copernicus died in the same year. It is said that he only saw a copy of his book once, when it was put into his hands on his deathbed.
The coming of the Renaissance as a single rush – in religion, art, literature, music, and mathematical science – was a head-on collision with the medieval system as a whole. To us the place of Aristotle’s mechanics and Ptolemy’s astronomy in the medieval system seems incidental. But to the contemporaries of Copernicus, they represented the natural and visible order of the world. The wheel as the Greek ideal of perfect motion had become a petrified god, as rigid as the Mayan calendar or the figures carved on Easter Island.
The system of Copernicus seemed unnatural to his age, even though the planets still run in circles. (It was a younger man, Johannes Kepler, working later in Prague, who showed that the paths are really elliptical.) That was not what bothered the man in the street, or in the pulpit. They were committed to the wheel of the heavens: the hosts of heaven must march around the earth. That had become an article of faith, as if the Church had made up its mind that the system of Ptolemy was invented not by a Levantine Greek but by the Almighty Himself. Clearly the issue was not one of doctrine but of authority. The issue did not come to a head until seventy years later, in Venice.
Two great men were born in the year 1564; one was William Shakespeare in England, the other was Galileo Galilei in Italy. When Shakespeare writes about the drama of power in his own age, he twice brings the scene to the Republic of Venice: once in The Merchant of Venice, and then in Othello. That is because in 1600 the Mediterranean was still the centre of the world, and Venice was the hub of the Mediterranean. And here ambitious men came to work, because they were free to work without restraint: merchants, and adventurers, and intellectuals, a host of artists and artisans crowded these streets, as they do now.
The Venetians had the reputation of being a secret and devious people. Venice was a free port, as we would say, and carried with that some of the conspiratorial air which haunts neutral cities like Lisbon and Tangier. It was in Venice that a false patron trapped Giordano Bruno in 1592 and handed him to the Inquisition, which burned him in Rome eight years later.
Certainly the Venetians were a practical people. Galileo had done deep work in fundamental science at Pisa. But what made the Venetians hire him as their professor of mathematics at Padua was, I suspect, his talent for practical inventions. Some of them survive in the historic collection of the Accademia Cimento in Florence, and are exquisitely conceived and executed. There is a convoluted glass apparatus for measuring the expansion of liquids, rather like a thermometer; and a delicate hydrostatic balance to find the density of precious objects, on the principle of Archimedes. And there is something which Galileo, who had a knack for salesmanship, called a ‘Military Compass’, though it is really a calculating instrument not unlike a modern slide-rule. Galileo made and sold them in his own workshop. He wrote a manual for his ‘Military Compass’ and published it in his own house; it was one of the first works of Galileo to get into print. This was sound, commercial science as the Venetians admired it.
So it is no wonder that when, late in 1608, some spectacle-makers from Flanders invented a primitive form of spyglass, they came to try to sell it to the Republic of Venice. But, of course, the Republic had in its service, in the person of Galileo, a scientist and mathematician immensely more powerful
than any in Northern Europe – and a much better publicist who, when he had made a telescope, bustled the Venetian Senate to the top of the Campanile to show it off.
Galileo was a short, square, active man with red hair, and rather more children than a bachelor should have. He was forty-five when he heard the news of the Flemish invention, and it electrified him. He thought it out for himself in one night, and made an instrument about as good, with a magnification of three, which is only about a rather superior opera glass. But before he came to the Campanile in Venice, he stepped the magnification up to eight or ten, and then he had a real telescope. With that, from the top of the Campanile, where the horizon is about twenty miles, you can not only see the ship at sea, you can identify it two hours’ sailing and more away. And that was worth a lot of money to the brokers on the Rialto.
Galileo described the events to his brother-in-law in Florence in a letter that he dated 29 August 1609:
You must know, then, that it is nearly two months since news was spread here that in Flanders there had been presented to Count Maurice a spy-glass, made in such a way that very distant things are made by it to look quite close, so that a man two miles away can be distinctly seen. This seemed to me so marvellous an effect that it gave me occasion for thought; and as it appeared to me that it must be founded on the science of perspective, I undertook to think about its fabrication; which I finally found, and so perfectly that one which I made far surpassed the reputation of the Flemish one. And word having reached Venice that I had made one, it is six days since I was called by the Signoria, to which I had to show it together with the entire Senate, to the infinite amazement of all; and there have been numerous gentlemen and senators who, though old, have more than once scaled the stairs of the highest campaniles in Venice to observe at sea sails and vessels so far away that, coming under full sail to port, two hours or more were required before they could be seen without my spy-glass. For in fact the effect of this instrument is to represent an object that is, for example, fifty miles away, as large and near as if it were only five.
Galileo is the creator of the modern scientific method. And he did that in the six months following his triumph on the Campanile, which would have been enough for anyone else. It occurred to him then that it was not enough to turn the Flanders toy into an instrument of navigation. It could also be turned into an instrument of research, an idea which was altogether new to that age. He stepped up the magnification of the telescope to thirty, and he turned it on the stars. In that way he really did for the first time what we think of as practical science: build the apparatus, do the experiment, publish the results. And that he did between September of 1609 and March of 1610, when he published in Venice the splendid book Sidercus Nuncius, The Starry Messenger, which gave an illustrated account of his new astronomical observations. What did it say?
[I have seen] stars in myriads, which have never been seen before, and which surpass the old, previously known, stars in number more than ten times.
But that which will excite the greatest astonishment by far, and which indeed especially moved me to call the attention of all astronomers and philosophers, is this, namely, that I have discovered four planets, neither known nor observed by any one of the astronomers before my time.
These were the satellites of Jupiter. The Starry Messenger also tells how he turned the telescope on the moon herself. Galileo was the first man to publish maps of the moon. We have his original watercolours.
It is a most beautiful and delightful sight to behold the body of the moon … [It] certainly does not possess a smooth and polished surface, but one rough and uneven, and, just like the face of the earth itself, is everywhere full of vast protuberances, deep chasms, and sinuosities.
The British ambassador to the Doge’s court in Venice, Sir Henry Wotton, reported to his superiors in England on the day that The Starry Messenger came out:
The mathematical professor at Padua hath … discovered four new planets rolling about the sphere of Jupiter, besides many other unknown fixed stars; likewise … that the moon is not spherical, but endued with many prominences … The author runneth a fortune to be either exceeding famous or exceeding ridiculous. By the next ship your lordship shall receive from me one of the [optical] instruments, as it is bettered by this man.
The news was sensational. It made a reputation larger even than the triumph among the trading community. And yet it was not altogether welcome, because what Galileo saw in the sky, and revealed to everyone who was willing to look, was that the Ptolemaic heaven simply would not work. Copernicus’s powerful guess had been right, and now stood open and revealed. And like many more recent scientific results, that did not at all please the prejudice of the establishment of his day.
Galileo thought that all he had to do was to show that Copernicus was right, and everybody would listen. That was his first mistake: the mistake of being naive about people’s motives which scientists make all the time. He also thought that his reputation was now large enough for him to be able to go back to his native Florence, leave the rather dreary teaching at Padua which had become burdensome to him, and leave the protection of this essentially anti-clerical, safe Republic of Venice. That was his second and, in the end, fatal mistake.
The successes of the Protestant Reformation in the sixteenth century had caused the Roman Catholic Church to mount a fierce Counter-Reformation. The reaction against Luther was in full cry; the struggle in Europe was for authority. In 1618 the Thirty Years War began. In 1622 Rome created the institution for the propagation of the faith from which we still derive the word propaganda. Catholics and Protestants were embattled in what we should now call a cold war, in which, if Galileo had only known it, no quarter was given to a great man or small. The judgment was very simple on both sides: whoever is not for us is – a heretic. Even so unworldly an interpreter of faith as Cardinal Bellarmine had found the astronomical speculations of Giordano Bruno intolerable, and had sent him to the stake. The Church was a great temporal power, and in that bitter time it was fighting a political crusade in which all means were justified by the end – the ethics of the police state.
Galileo seems to me to have been strangely innocent about the world of politics, and most innocent in thinking that he could outwit it because he was clever. For twenty years and more he moved along a path that led inevitably to his condemnation. It took a long time to undermine him; but there was never any doubt that Galileo would be silenced, because the division between him and those in authority was absolute. They believed that faith should dominate; and Galileo believed that truth should persuade.
That clash of principles and, of course, of personalities came into the open at his trial in 1633. But every political trial has a long hidden history of what went on behind the scenes. And the underground history of what came before the trial lies in the locked Secret Archives of the Vatican. Among all these corridors of documents, there is one modest safe in which the Vatican keeps what it regards as the crucial documents. Here, for example, is the application of Henry VIII for divorce – the refusal of which brought the Reformation to England, and ended the tie to Rome. The trial of Giordano Bruno has not left many documents, for the bulk were destroyed; but what exists is here.
And there is the famous Codex 1181, Proceedings Against Galileo Galilei. The trial was in 1633. And the first remarkable thing is that the documents begin – when? In 1611, at the moment of Galileo’s triumph in Venice, in Florence, and here in Rome, secret information was being laid against Galileo before the Holy Office of the Inquisition. The evidence of the earliest document, not in this file, is that Cardinal Bellarmine instigated inquiries against him. Reports are filed in 1613, 1614, and 1615. By then Galileo himself becomes alarmed. Unbidden, he goes to Rome in order to persuade his friends among the Cardinals not to prohibit the Copernican world system.
But it is too late. In February of 1616, here are the formal words as they stand in draft in the Codex, freely translated:
Propositions
to be forbidden:
that the sun is immovable at the centre of the heaven;
that the earth is not at the centre of the heaven, and is
not immovable, but moves by a double motion.
Galileo seems to have escaped any severe censure himself. At any rate, he is called before the great Cardinal Bellarmine and he is convinced, and has a letter from Bellarmine to say, that he must not hold or defend the Copernican World System – but there the document stops. Unhappily, there is a document here in the record which goes further, and on which the trial is going to turn. But that is all seventeen years in the future.
Meanwhile Galileo goes back to Florence, and he knows two things. One is that the time to defend Copernicus in public is not yet. And the second, that he thinks that there will be such a time. About the first he is right; about the second, no. However Galileo bided his time, until – when? Until an intellectual Cardinal should be elected Pope: Maffeo Barberini.
That happened in 1623, when Maffeo Barberini became Pope Urban VIII. The new Pope was a lover of the arts. He loved music; he commissioned the composer Gregorio Allegri to write a Miserere for nine voices, which long afterwards was reserved for the Vatican. The new Pope loved architecture. He wanted to make St Peter’s the centre of Rome. He put the sculptor and architect Gianlorenzo Bernini in charge of completing the interior of St Peter’s, and Bernini boldly designed the tall Baldacchino (the canopy over the Papal throne), which is the only worthy addition to Michelangelo’s original design. In his younger days the intellectual Pope had also written poems, one of which was a sonnet of compliments to Galileo on his astronomical writing.
Pope Urban VIII thought of himself as an innovator. He had a confident, impatient turn of mind:
The Ascent of Man Page 13