Galileo’s Dream

Chapter Two I Primi Al Mondo

Having come to this pass, I appealed out of my innocent soul to the high and omnipotent gods and my own good genius, beseeching them of their eternal goodness to take notice of my wretched state. And behold! I began to descry a faint light.

-FRANCESCO COLONNA, Hypnerotomachia PoliphiliThe Strife of Love in a Dream of Poliphili

The next night, back in Padua, Galileo went out into his garden and aimed his best occhialino at the moon. He left Mazzoleni sleeping by the kitchen fire, woke none of the servants; the house was asleep. This was his hour, as on so many nights when his insomnia took hold of him.

Now his mind was filled with the stranger’s blade of a face, his intense gaze: have you looked at the moon? The moon tonight was near its first quarter, the bright part almost exactly half the whole, the dark part easily visible against the night sky. An obvious sphere. Galileo sat on a low stool, held his breath, brought his right eye to the eyepiece. The little black circle of glass was marked on its left side by a luminous white patch. He focused on it.

At first he saw nothing but a chiaroscuro flecking of greyish black and brilliant white, the tremble of the white seeming to flow over the dark spots. Ah: hills. A landscape. A world seen from above.

A view from world to world.

He loosened the screw on the tripod head and tapped the tube, trying to capture in the glass the tip of the moon’s upper crescent. He tightened the screw, looked again. Brilliant white horn: a dark grey in the curve of the horn, a blackness just slightly washed with white. Again he saw an arc of hills. There, at the border of light and dark, was a flat dark patch, like a lake in shadow. The sunlight was obviously shining horizontally over the landscape, as it would be of course, as he was looking at the area experiencing dawn. He was looking at a sunrise on the moon, twenty-eight times slower than a sunrise on Earth.

There was a little round valley; there another one. Any number of circles and arcs, in fact, as if God had been fooling around up there with a compass. But the strongest impression remained the range of hills, there on the border of black and white.

The moon was a world, the Earth was a world. Well, of course. He had always known this.

As for the assertions the Aristotelians made about the moon, that because it was in the heavens it was therefore a perfect sphere, made of some unearthly crystal that was of unchanging purity-well, its ordinary appearance had always rendered that a very suspicious statement. Now it was clearer than ever that Aristotle had been wrong. This was no great surprise-when indeed had he been right, in the natural sciences? He should have stuck to his strength, which was rhetoric. He had had no mathematics.

Galileo got up and went in to the workshop to get his current folio, and a quill and inkpot. He wondered if he should wake Mazzoleni, then decided against it. There would be other nights. This one was his. He could feel his blood pounding in his head; his neck muscles were sore. It was his night. No one had ever seen these things. Well, perhaps the stranger had. But Galileo suppressed that thought in order to glory in his own moment. All the years, all the centuries and their millions come and gone, the stars rotating above them night after night, and only now had someone seen the hills of the moon.

The moon must rotate on its axis at the same speed it circled the Earth, to keep the same side always facing it; this was odd, but no odder than many other phenomena, such as the fact that the moon and the sun were the same size in the sky. These things were either caused, or accidental; it was hard to tell. But it was a rotating sphere, that was clear. And so was the Earth also a rotating sphere? Galileo wondered if Copernicus’s advocacy of this old Pythagorean notion could be right.

He looked through the glass again, relocated the white hills. The dark part west of them was extremely interesting. Land in shadow, obviously. Perhaps there were lakes and seas too, though he could see no sign one way or the other. But it was not as black as a cave or a dark room at night. One could make out dim large features, because the area was very slightly illuminated. That could not be direct sunlight, obviously. But just as the moonlight illuminating his garden at this moment was really sunlight bouncing off the moon to him, he was no doubt also seeing the dark part of the moon illuminated by sunlight that had bounced off the Earth and struck it-and then bounced back yet again, of course, to get to his eyes. From sun to Earth to moon and then back to him-which would explain the successive diminutions in brightness. As sunlight was to moonlight, moonlight was to the dark side of the moon.

The next morning he said to Mazzoleni, ‘I want a stronger magnification, something like twenty or thirty times.’

‘So you say, maestro.’

They manufactured a lot of spyglasses. Making the objective lenses bigger and smoother, while keeping the eyepiece lenses at their original size and grinding them both deeper and smoother, led to very satisfactory jumps in magnifying power. In a matter of weeks they had glasses that showed things twenty-twenty-five- thirty-finally thirty-two times closer than the unaided eye saw them. There they hit their limit; the lenses could not be made bigger or smoother, and the tubes were twice as long as when they had begun. Also, as magnifying power grew, what one actually saw through the glass contracted down to a very small field of view. One could move one’s eye around the eyepiece a bit to broaden the view, but not by very much. Accurate aiming was important, and Galileo got better at this by attaching an empty spotting tube to the side of the strongest glass. They also had to deal with a white glare that invaded the sides of the larger images, where the irregularities in the lenses also tended to cluster, so that the outer circumference of the image was often nearly useless. Here Galileo put to use a solution he had discovered to deal with the rainbow rings that plagued his own vision, especially of things seen at night. This unhappy phenomenon he tended to attribute to the strange incident of his near-death experience in the cellar of the Villa Costozza, which he also believed had caused his rheumatism, bad digestion, headaches, seizures, melancholia, hypochondria, and so on. Vision problems were only one more remnant of that ancient disaster, and he had long since discovered that if he looked at something through his fist, the aurora of coloured light surrounding the thing would be blocked from view. Now he tried the same remedy with the new spyglasses, fashioning with Mazzoleni’s help a cardboard sleeve that could be fitted over the objective. The most effective one left an oval opening over the lens that blocked most of the outer third of its area. Why an oval worked better than a circle he had no idea, but it did; the glare was eliminated, and the image that remained was about as large as before, and very much sharper.

As the spyglasses got stronger, things in the sky were becoming visible that had not been visible before. One night, after a long inspection of the moon, he swung the glass across the sky toward the Pleiades, just risen above the house. He looked into the glass.

‘My God,’ he said, and felt his body ringing. Around the Seven Sisters were scores of stars. The familiar seven stars of the gorgeous little constellation were brighter than the rest, but surrounding them were thickets of lesser stars, granulated almost to white dust in places. The sense of enormous depth in the little black circle was palpable, almost vertiginous; he swayed a little on his stool, mouth hanging open. Even the spectacle of the mountainous moon had not prepared him for such a thing. No one else in the history of the world had ever seen these stars, until this very night, this very moment. It was the oddest feeling in the world. He sketched a quick map of the newly crowded group, making the familiar sisters little sixpointed stars like a child would draw, with the new stars tiny crosses-the drawing done almost unconsciously, a kind of nervous habit, deeply engrained after so many years of exercising it. Until he sketched something down his hand would itch with the urge.

He looked until his eyes hurt, and the points of light swam in the eyepiece like gnats in the sun. He was cold, almost shivering, his bad back like a rusty hinge inside him. He felt that he would sleep the moment he lay down: a luscious feeling for a lifelong insomniac, he bathed in it as he stumbled off to bed.

His empty bed. No Marina. He had kicked her out, and life was ever so much more peaceful. Nevertheless he felt a quick stab of regret as he dived into the deep pool of sleep. It would have been nice to have someone to tell. Well-he would tell the world. The thought almost woke him.

Only six days after his demonstration to the Venetian Senate, his reward came, in the form of a new contract offer. Procurator Antonio Prioli, one of the heads of the university in Padua, came out of the Sala delle Senato to take Galileo by the hand. ‘The Senate, knowing the way you have served Venice for seventeen years, and sensible of your courtesy in offering your occhialino as a present to the Republic, has ordered your election to the Professorship for life, if you are willing, with a salary of a thousand florins a year.’ He raised his other hand: ‘They are aware that there remains a year on your current contract, and yet want the increase in salary to begin this very day.’

‘Please convey to His Serenity and all the pregadi my deepest thanks for this most kind and generous offer, Your Honour,’ Galileo said. ‘I kiss their hands, and accept with the utmost gratitude.’

‘Shit,’ he said the moment he was out of earshot. And back home he started cursing in a way that emptied the rooms well before he stormed through them. ‘Shit shit shit. Those pricks! Those cheap bastards, those soddomitecci!’

He remembered as he always did that Cremonini, an old duffer Galileo had enjoyed sparring with through the years, already made a thousand florins a year from the Venetian Senate. That was the difference between the standing of philosophy and mathematics in this world, an inverse ratio to justice, as so often happened: the worst philosopher had been paid twice the best mathematician.

Then also, a salary fixed in perpetuity meant there would never be another raise, and Galileo already knew to the last quattrini his expenses, which were such that this raise would only just cover them, leaving him still unable to pay off his sister’s dowry and his other outstanding debts.

Also, the salary was a salary, paid for his teaching, as before-meaning there would be no time to write up his experiments, or make new ones. All that work in the notebooks in the workshop would continue to lie there mouldering.

So this was not exactly the most exciting result one could have imagined, given the extraordinary power of his new device, and its strategic importance, obvious to everyone who had witnessed the demonstration. The triumph of that day had had Galileo imagining a lifetime sinecure, all his debts and expenses paid, and afterward free from all work except research and consultation, which he would have applied most faithfully to the good fortune of La Serenissima. They would have benefited greatly; and in any duchy or principality or kingdom this kind of patronage would not have been unusual. But Venice was a republic, and courtly patronage as it was practised in Florence or Rome, or almost anywhere else in Europe, did not exist here. Gentlemen of the Republic worked for the Republic, and were paid accordingly. It was an admirable thing, if you could afford it.

‘Shit,’ he repeated weakly, staring at his workshop table. ‘Those cheap bastards.’ But a part of his mind was already calculating what the thousand florins a year would do to meet expenses and knock off debts.

Then he heard in a letter from Sarpi that some of the Senators had complained to the body at large that the spyglass was a commonplace in Holland and elsewhere in northern Europe, so that it had not really been Galileo’s achievement, and he had presented his device under false pretences.

‘I never said I invented the idea!’ Galileo protested. ‘I only said I made it much better, which I did! Tell those cheap bastards to find a spyglass as good as mine somewhere else if they think they can!’ He ripped off a long letter that he sent to Sarpi to give to the senators:

News arrived at Venice, where I happened to be at the moment, that a Dutchman had a glass looking through which one could see distant things as clearly as if they were near. With this simple fact I returned to Padua, and pondering on the problem, I found the solution on the first night home, and the next day I made an instrument and reported the fact to my friends at Venice. I made a more perfect instrument, with which I returned to Venice, and showed it to the wonder and astonishment of the illustrati of the Republic-a task which caused me no small fatigue.

But perhaps it may be said that no great credit is due for the making of an instrument, when one is told beforehand that the instrument exists. To this I reply, the help which the information gave me consisted of exciting my thoughts in that particular direction, and without that, of course it is possible they may never have gone that way; but that the simple information itself made the act of invention easier to me I deny, and say more-to find the solution to a definite problem requires a greater effort of genius than to resolve one not specified; for in the latter case accident, mere chance, may play the greater part, while in the former all follows from the work of the reasoning and intelligent mind. Thus, we are quite sure that the Dutchman was a simple spectacle-maker, who, handling by chance different forms of glasses, looked also by chance through two of them, and saw and noted the surprising result, and thus found the instrument. Whereas I, at the mere news of the effect obtained, discovered the same instrument, not by chance, but by way of pure reasoning! I was not assisted in any way by the knowledge that the conclusion at which I aimed already existed. Some people may believe that the certainty of the result aimed at affords great help in attaining it: let them read history, and they will find that Archites made a dove that could fly, and that Archimedes made a mirror that burned objects at great distances. Now by reasoning on these things such people will doubtless be able, with very little trouble and with great honour and advantage, to tell us how they were constructed. No? If they do not succeed, they will then be able to testify to their own satisfaction that the ease of fabrication which they had promised themselves from the foreknowledge of the result is very much less than what they had imagined-

‘Idiots that they are!’ Galileo shouted but did not add to the end of the letter, signing it conventionally and sending it off.

Naturally Sarpi did not forward this letter to the Senate, but rather came out to Padua to assuage his angry friend. ‘I know,’ he said apologetically, putting his hand to Galileo’s freckled cheek, now as red as his hair as he recounted the reasons for his fury. ‘It isn’t fair.’

And it was even less fair than Galileo thought; for Sarpi now told him that the Senate had decided that the stipulated raise in Galileo’s salary was not to go into effect immediately after all, but would begin the following January.

At this Galileo blew up again. And after Sarpi left he immediately took action to deal with the insults, working in two directions. In Venice, he returned to the city with a much more powerful spyglass, the best his artisans had made so far, and gave it to the Doge as a present, indicating again how useful it would be to the protection of the Republic, how grateful he was for the new contract, how much the splendiferousness of the Doge illuminated not just the Serenissima but the entire watershed of the Po, et cetera. Dona would take note of this generosity, perhaps, in the face of what could be seen as a very tepid response from his Senate, even a rebuff; and then maybe he would act to revise the raise accordingly. It was not the likeliest response, but it could happen.

Then, on the Florentine front, always a part of his life, even in these last seventeen years in Padua working for Venice, Galileo wrote to young Grand Duke Cosimo’s secretary Belisario Vinta, telling him about the spyglass, offering to give the prince one of them and to instruct him in its use. A few of the closing phrases of this letter began the process of asking for patronage at the Medici court.

There were some difficulties to be negotiated here. Galileo had been tutor to young Cosimo when his father Ferdinando was the Grand Duke, and that was good. But he had also been asked to work up a horoscope for Ferdinando the previous year, and had done so, and found that the stars predicted a long and healthy life for the Grand Duke, in the usual way; but then shortly thereafter Ferdinando had died. That was bad. In the tumult of the funeral and the succession no one had said anything, nor even seemed to remember the horoscope, except for a single penetrating glance from Vinta the next time they met. So perhaps in the end it had not mattered; and Galileo had taught Cosimo his mathematics, and treated him very kindly, of course, so that they had grown fond of one another. Cosimo was a bright young man, and Cosimo’s mother, the Grand Duchess Christina, was a very intelligent woman, and fond of Galileo-indeed, his true first patron at that court. And as Cosimo was so young, and new to his rule, she was a regent-like power. So the possibilities there were very real. And when all was said and done, Galileo was a Florentine, it was his home. His family was still there, which was bad, but unavoidable.

So, still very angry at the Venetians for their ingratitude, he neglected his classes at Padua, wrote great flurries of letters to influential friends, and began to lay plans to move.

Despite the discord and chaos of the tumble of days, he spent every cloudless night out in the garden, looking through the best glass they had on hand. One night he woke Mazzoleni and took him out to look at the moon. The old man peered up through the tube and then pulled his head back, grinning, shaking his head in amazement. ‘What does it mean?’

‘It’s a world, like this one.’

‘Are there people there?’

‘How should I know?’

When the moon was up, and not too full, he looked at it. Long ago he had taken drawing lessons from his Florentine friend Ostilio Ricci, the better to be able to sketch his mechanical ideas. One of the exercises in Ricci’s treatise on perspectival drawing had been to draw spheres studded with geometrical figures, like raised pyramids or cubes, each one of which had to be drawn slightly differently to indicate where they stood on the hidden surface of the sphere underneath them. This was a meticulous and painstaking form of practice, very polito, at which Ricci had conceded Galileo eventually became the superior. Now Galileo found that it had given him the necessary skills, not just to draw the things the glass showed on the moon, but even to see them in the first place.

It was particularly revealing to draw the moon’s terminator, where light and shadow mixed in patterns that changed from night to night. As he wrote in his workbook, With the moon in various aspects to the Sun, some peaks within the dark part of the moon appear drenched in light, although very far from the boundary line of the light and darkness. Comparing their distance from that boundary line to the entire lunar diameter, I found that this interval sometimes exceeds the twentieth part of the diameter. The moon’s diameter had been proposed since antiquity to be about two thousand miles; thus he had enough to complete a simple geometrical calculation of the height of these lunar mountains. He drew the moon as a circle, then on it drew a triangle with one side the radius at the terminator, another a radius running up to the tip of the lit mountain in the dark zone, and the third line following the beam of sunlight from the terminator to the mountain top. The two sides meeting at the terminator would be at right angles, and he had distances for both, based on the assumed diameter, and thus he could use the Pythagorean theorem to calculate the length of the hypotenuse. Subtracting the moon’s radius from that hypotenuse, one was left with about four miles of difference-which was the height of the mountain above the surface.