Galileo's Dream (66 page)
Authors: Kim Stanley Robinson
La Piera kept the household going through the long silence. She dropped his food before him with the same absent methodical air she had when she chopped the heads off the chickens. Galileo ate as if he were dead. He too had heard the silence, which came out of an abyssal blackness. He knew now that all the wailing after his trial had been at nothing. To be distressed at the judgment of other men, over nothing more than an idea; it was absurd. Well, grief too was an idea. And as
you got older, your grief grew in you. Probably there was an equation for this change in grief, a rate of acceleration. Like a dropped rock. You collect all your selves together just in time to smash to the ground, and so it all goes to waste. The dust devil falls to the ground, its whirlpool of wind gone. The atoms, the affectinos of that particular field disperse. If anything is conserved, he thought as he sat in the garden, looking at the signs of spring in all the plants, it must be in the generations that follow. Something that could be put to use. This was all that would remain in time.
One afternoon he walked down to the convent and found Suor Arcan-gela. She was startled to see him and turned her face away.
“Sit down,” he said. “I've brought some candied citron.” And he sat on a bench in the sun. She would not speak, but the citron slices were hard to resist. Eventually she sat on the far end of the bench. She took the slices and ate them, all the while looking the other way. After a while she curled on the bench like a cat, her back to him, but in such a way that the back of her head just touched the side of his leg. It seemed she fell asleep.
Galileo sat there looking at the strawberry plants at his feet. The new leaves came out of the ground neatly folded. Any new leaf was a remarkable thing when considered closely. The little plant emerged from brown mud that was granulated and unpromising. Wet dirt, nothing more. And yet there were the new leaves. Earth, water, air, the subtle fire of sunlight, driving the life into everything. Something in the mix of these, and something beyond them ⦠For a long time he sat there staring, feeling on the edge of understanding, of seeing things clearly. The feeling swelled in him as he realized that it was an emotion he felt all the time, that his entire life had been one protracted case of
presque vu
. Almost seen! Almost understood! The blue sky quivered with this feeling.
On his way home he stopped to see the abbess. Recently Arcangela had been leaving the convent and wandering Arcetri and the country lanes around the village, until someone noticed and she had to be retrieved. Now Galileo said to the abbess, “Just let her go if she goes. She'll always come back in time for supper. If she doesn't I'll send one of the boys out to get her.”
T
HEN, BECAUSE HE WAS OLD,
because he had lost everything and all the people he loved most had died, because life had no meaning and there was nothing left to do to fill his preposthumous hours, he occupied his time writing up his results from the experiments he and Mazzoleni had performed in Padua, forty years before.
To get him started, we put his old folios out on the table under the arcade, as if taking them out there to be dusted. Sometimes he would turn the pages, and then with a heavy sigh he would take up a pen and jot down some notes, or transcribe some conversation going on in his head. It was only a way to pass the time before death took him; at least at first.
Then somehow it got its hooks into him, and made him sweat and grunt in the old way. Work, work, work; the work of thinking, the work of understanding something that had never been understood before; this was the hardest work in the world. And he liked that. He needed that. Arcangela still would not speak to him, even though she sometimes wandered up to the house, skulking around the gate like a stray dog. The Lady Alessandra was still in Germany, and his letters
to her could only be so long, especially when so much of what he wanted to say to her could not be written down, but only translated into comments on gardening and the weather. After the mornings when he wrote those letters, the hours hung heavy on him. And yet the book of his life was still there to be written. So, hey to.
Almost all of the material had been in his mind, or at least in his notes, since before 1609, when the arrival of the telescope had upended his life. He had noted and sketched the various raw propositions during the intense collaboration with Mazzoleni in the Padua workshop, thinking at the time that he would write them up formally in book form during the following school year. Now it was thirty years since he had stopped, and some of the notes had been transcribed by Guiducci and Arrigheti, but most of the notebooks he had not even opened again since that time. Some pages he even had serious trouble understanding. It was like reading the handwriting of another man; and he supposed that was actually the case, because now he was only revising the work of an entirely different Galileo, a younger and more nimble mind. What if all those past selves don't count, he thought as he looked at the notebooks, no matter how much they wrote down? What if the person you are now is really the only person that matters? Because that's how it is.
So he worked, and lost himself in geometries. The horrible year 1634 passed. A whole crop grew in the fields, there was weed after weed to kill, and after a while he grew unable to recognize his grief as something discrete. It was now simply the world, the way things were.
Pages piled up. He kept using the format of dialogues between Salviati, Sagredo, and Simplicio. This little defiance was a good sign, we all thought; using those names had not been forbidden, the dialogue form had not been forbidden, and yet they would remind everyone of the book that had been forbidden. Of course it was likely they would ban this one before it was ever published. The
Dialogo
and the
Discorsi
âtwo very dangerous books, being so real.
He found it interesting to read over his old notes and diagrams. As he did so, he could not help but recall also all the other things that had happened in Padua when he had been writing these pages. Eighteen
long years of teaching mathematics to the students at Il Bo and living in the house on Via Vignaliâlecturing, tutoring, working on the military compass, inventing new devices, trying to determine various qualities and properties in the workshop demonstrations. Here was a page on the weight of air as compared to water, for instance. Then also taking the barge out to Venice, to eat and drink and talk with his friends, and play with the 248 girls, and later to see Marina. It was all a jumble, like a kind of carnival inside him, and he could not in fact associate any given experiment with any given year, it was all as one and of a piece: Padua. It was strange how that time felt like it had happened just yesterday, and yet also was separated from him by an abyss of a million yearsâyet another example of time's odd doubled aspect. Strange also that he had fought with such fury to escape that life, when it had turned out to be precisely the happiest time he would ever have! How could he have been so stupid? How could he not have known what he had? There was a deep stupidity in ambition, a blindness in it, the way it was so serious, so unplayful. It failed to value the moment, and so failed to recognize happiness, even though that was the most important consideration of all. It failed to value the ringing feeling that had come over him, as when he saw a proof, or on that first night with Marina, or sometimes on the dawn barges back over the lagoon to terra-firma. These were the moments that mattered.
“Mazzoleni, I am stupid.”
“I don't know, maestro,” the old one objected. “Where does that leave the rest of us?”
“Ha-ha.”
Eventually, these moments he was trapped in now would also meld together and become all of a piece: the mornings splayed in the garden, the afternoons working on the new dialogues; the grief for Maria Celeste, infusing everything with its black light. Arcangela turning her head away when he visited, the look that was not a look, and thus worse than any look, which at the very least was a contact. His sister-in-law, Anna Chiara Galilei, moving into Il Gioièllo with three daughters and her youngest son Michelangelo, then all five of them promptly dying of the plague. More black light piercing all; all part of the one thing of this particular time.
People continued to write to him, and one morning that fall, he got up and stacked up all their letters and started writing back. He answered
questions, and inquired about other people's physical or mathematical investigations, and told people about the new dialogues he had begun. It was of course unlikely he could ever have these dialogues published. That he was using the same three characters only increased the difficulty. So when a correspondent he had never met, Elia Diodati, wrote from Holland asking him if he could help with publication of a new book, Galileo quickly agreed.
At first this seemed like a good thing; but we noticed that Galileo soon began to create more requirements for the book, so that it appeared he would never be able to finish it. It became obvious he didn't want to finish it, that for him that would be like finishing his life. He was trying to fit in everything he had ever learned, or even thought to be possibleâeverything but the cosmological matters he was forbidden to discuss. Those in any case remained speculative matters, mysterious no matter how hard one tried to see into themâas was made clear by the confounding information coming in from correspondents about tide times in the Atlantic, which made his theory of how tides were formed seem clearly wrong, as he had to admit in his replies.
Whereas on the other hand, with these simple propositions about motion, force, friction and strength, he could stick to only those assertions that he had demonstrated by experiment. After all the guesses about comets and stars and sunspots, about buoyancy and magnetism and all the fascinating mysteries he did not have any basis for comprehending, that were in the end the equivalent of astrology, it was a tremendous pleasure to write down only what he had seen and tested. “This is the book I should have written all along,” he said one day as he finished writing. “This and only this. I should have avoided words and stuck to equations, like Euclid.”
Let AC be the inclined plane and AB the perpendicular, each having the same vertical height above the horizontal, namely, BA; then I say, the time of the descent along the plane AC bears a ratio to the time of fall along the perpendicular AB, which is the same as the ratio of the length AC to AB.
Space and time, in a relation. So satisfying! A little bell rings!
In the new book's first day of dialogue, there in the pink ark of Sagredo's palazzo on the Grand Canal in his mind, he had Salviati,
Sagredo, and Simplicio discuss the following subjects: ratios of size to strength in machines; the strength of braided rope; a method for separating the action of the vacuum from other causes; the breaking point of a column of water, which was always eighteen cubits; the role of fire in liquefying hot metals; the paradox of an infinite within an infinite; the geometry of shrinking surfaces; an experiment that might determine the speed of light; problems and theorems in projective geometry; questions of buoyancy and the speed of falling objects; the question of why water beads up on some surfaces; what terminal velocity is, and air resistance, as well as water resistance and the resistance of a vacuum; results of attempts to weigh air, to find out the ratio of the weight of water to air (which was forty to one, not Aristotle's ten to one); results from the experiments on inclined planes to measure the speed of falling objects; designs for pendulums made of different materials; questions of percussion and impact; and lastly, a long discussion of harmonies and dissonances in music, explained as functions of proportion in vibrations of a pendulum string, with speculations as to why such strong emotions could be created by such sounds.
On the second day, the three characters discussed the equilibrium and balance of beams, the longitudinal and latitudinal strength of beams, strength as a function of size, and strength as a function of shape.
On the third day, they discussed questions of motion, both local and uniform; questions of speed and distance; naturally accelerated motions, in which everything was said about gravity but the word itself; inclined plane experiments to test motion; pendulum experiments for same; and various inclined plane theorems of equal speeds, with comparisons to vertical fall.
On the fourth day the three discussed the motion of projectiles, as being a combination of uniform and naturally accelerated motion, thus leading to the theorem of the semiparabola, with lots of tables recording information from experiments to support these assertions, and to let the objects speak for themselves.
Early in the dialogue of the first day, Salviati said something that startled Galileo when he read it later:
And here I must relate a circumstance which is worthy of your attention, as indeed are all events which happen contrary to expectationâespecially
when a precautionary measure turns out to be a cause of disaster.
That was 1615, he suddenly saw; his precautionary measure had led to disaster. But how could you tell until after the fact? And so didn't you have to try? You did. You could only try. You learn things that make you try.
He had done what he could with what he had. As he wrote on, thinking about this, he had Salviati defend his practice:
Our Academician has thought much upon this subject, and according to his custom has demonstrated everything by geometrical methods, so that one might fairly call what he does a new science.
“Who has demonstrated everything by geometrical methods!” Galileo said, reading it with a shake of the head. “Ha. If only you could. That would be a new science indeed.”
As the book continued to pile up, page after page, he kept writing down things that surprised him laterâthings he didn't know that he knew.
The attributes “equal,” “greater,” and “less” are not applicable to infinite quantities.
Amazing the force which results from adding together an immense number of small forces. There can be no doubt that any resistance, so long as it is not infinite, may be overcome by a multitude of minute forces.
Infinity and indivisibility are in their very nature incomprehensible to us; imagine then what they are when combined. Yet that is our world.
Any velocity once imparted to a moving body will be rigidly maintained as long as the external causes of acceleration or retardation are removed ⦠motion along a horizontal plane is perpetual; for if the velocity be uniform, it cannot be diminished or slackened, much less destroyed.
A body which descends along any inclined plane and continues its
motion along a plane inclined upwards, will, on account of the momentum acquired, ascend to an equal height above the horizontal; and this is true whether the inclinations of the two planes are the same or different.
At times when he wrote it seemed as if Salviati and Sagredo were still alive somewhere and talking to him from that place, their minds as lively as ever. Sometimes he put into the book actual things he had heard them say in life, as when he included one of Salviati's many fine offhand remarks
:
I shall attempt to remove, or at least diminish, one improbability by introducing a similar or greater one, just as sometimes a wonder is diminished by a miracle.
A wonder diminished by a miracle. That had happened to him fairly often, it seemed. He had lived in a miracle.
At times these voices from the page said things with a mysterious power to move him.
Please observe, gentlemen, how facts which at first seem improbable will, even on scant explanation, drop the cloak which has hidden them and stand forth in naked and simple beauty.
He had seen that, he felt; seen the cloak drop, and beauty stand forth. An image evoked by the phrase pushed at the back of his eyes, naked and simple, not seen but almost seen. A beauty like Marina, but taller.
Later a strange sensation struck him again, very powerfully, when he read over a passage in which Salviati and Sagredo began talking about musical strings vibrating either in time or out of time,
spro-porzionatamente
, and Salviati suggested that within those interference patterns, every wave held secret lives. As he read over the passage, Galileo did not quite remember writing it.
A string which has been struck begins to vibrate and continues the motion as long as one hears the sound
(risonanza);
these ripples expand far into space, and set into vibration not only strings, but also
any other body which happens to have the same period as the plucked string. The undulations of the medium are widely dispersed about the sounding body, as shown by the fact that a glass of water may be made to emit a tone merely by the friction of the fingertip upon the rim of the glass; for in this water is produced a series of regular waves. Would it not be a fine thing if one had the ability to produce waves which would persist for a long while, even months and yearsâeven centuries?
Sagredo: Such an invention would, I assure you, command my admiration.
Salviati: The device is one which I hit upon by accident; my part consists merely in the observation of it, and in the appreciation of its value as a confirmation of something which I plunged into quite deeply.