And then a strange amp; wonderful thing occurred. The two sickle shapes, or moonlets, lying between the flattened sides of the oval and the ideal circular orbit, had a width at their thickest points amounting to 0.00429 of the radius of the circle. This value was oddly familiar (I cannot say why: was it a premonition glimpsed in some forgotten dream?). Now I became interested in the angle formed between the position of Mars, the sun, and the centre of the orbit, the secant of which, to my astonishment, I discovered to be 1.00429. The reappearance of this value-. 00429-showed me at once that there is a fixed relation between that angle, and the distance to the sun, which will hold good for all points on the planet's path. At last, then, I had a means of computing the Martian orbit, by using this fixed ratio.
You think that was the end of it? There is a final act to this comedy. Having tried to construct the orbit by using the equation I had just discovered, I made an error in geometry, and failed again. In despair, I threw out the formula, in order to try a new hypothesis, namely, that the orbit might be an ellipse. When I had constructed such a figure, by means of geometry, I saw of course that the two methods produced the same result, and that my equations was, in fact, the mathematical expression of an ellipse. Imagine, Doctor, my amazement, joy amp; embarrassment. I had been staring at the solution, without recognising it! Now I was able to express the thing as a law, simple, elegant, and true: The planets move in ellipses with the sun at one focus. God is great, and I am his servant; as I am also,
your humble friend, Johannes Kepler
V Somnium
Already the light was failing when he arrived in Regens-burg at last. A fine rain drifted slantwise through the November dusk, settling in a silver fur on his cloak, his breeches, the nag's lank mane. He crossed the Steinerne Brücke over the sullen surge of the Danube. Dim figures, faceless and intent, passed him by in the streets. There was an ominous hum in his ears, and his hands, clutching the greasy reins, trembled. He told himself it was fatigue and hunger: he could not afford to be ill, not now. He had come to accost the Emperor, to demand a settlement of what he was owed.
The lamps were lit in Hillebrand Billig's house. From a way off he spied the yellow windows and the taverner and his wife within. It was an image out of a dream, that light shining through the brown gloom and the rain, and folk attending his coming. The old horse clattered to a stop, coughing. Hillebrand Billig peered at him from the doorway. "Why, sir, we did not expect you until the morrow. "
Always the same, too late or too early. He was not sure what day of the week it was.
"Well, " stamping his numbed feet, tears in his eyes from the cold, "here I am!"
He was put to dry by the fire in the kitchen, with a platter of ham and beans and a pint-pot of punch, and a cushion for his seething piles. An elderly dog snoozed at his feet, gasping and growling in its sleep. Billig fussed around him, a large leather-clad man with a black beard. At the stove Frau Billig stood paralysed by shyness, smiling helplessly upon her saucepans. Kepler no longer remembered how or when he had come to know the couple. They seemed to have been always there, like parents. He smiled vacantly into the fire. The Billigs were twenty years younger than he. Next year would be his sixtieth.
"I am bound for Linz," he said. He had just remembered that. There was interest on some Austrian bonds to be collected.
"But you'll bide with us a while?" said Hillebrand Billig, and, with ponderous roguishness: "The rate here, you know, heh, is cheap. " It was his only joke. He never tired of it. "Is that not so, Anna?"
"O yes," Frau Billig managed, "you will be very welcome, Herr Doctor."
"Thank you," Kepler murmured. "I must, yes, spend a few days here. I have to see the Emperor, he owes me moneys."
The Billigs were impressed.
"His majesty will soon be returning to Prague," said Hillebrand Billig, who prided himself on knowing about these matters. "The congress has finished its business, I hear."
"But I will catch him, all the same. Of course, as to whether he will be prepared to settle his account with me, that is another question. " His majesty had larger matters on his mind than the imperial mathematician's unpaid salary. Kepler sat upright suddenly, slopping his punch. The saddlebags! He rose, making for the door. "Where is my horse, what has become of my horse?" Billig had sent it to the stables. "But my bags, my my… my bags!"
"The boy will bring them. "
"O." Kepler, moaning, turned this way and that. All of his papers were in those satchels, including a stamped and sealed imperial order for the payment of 4,000 florins from the crown's debt to him. The merest tip of something unspeakable was shown him briefly with a grin and then whisked away. Aghast, he sat down again, slowly. "What?"
Hillebrand Billig leaned down to him, mouthing elaborately. "I say, I will go out myself and bring them in, your bags, yes?"
"Ah."
"Are you unwell, Doctor?"
"No no… thank you."
He was trembling. He remembered out of his childhood a recurring dream, in which a series of the most terrible tortures and catastrophes was unfolded leisurely before him, while someone whom he could not see looked on, watching his reactions with amusement and an almost friendly attention. Just now that vision, whatever to call it, had been like that, the same slick flourish and the sense of muffled gloating. That was more, surely, than simply fear for his possessions? He shivered. "Eh?" Frau Billig had spoken. "Beg pardon, ma'am?"
"Your family," she said, louder, smiling nervously and plucking at her apron; "Frau Kepler, and the children?"
"O, they are very well, very well. Yes." A faint spasm, almost a pain, passed through him. It took him a moment to identify it. Guilt! As if by now he were not familiar with that. "We have lately had a wedding, you know. "
Hillebrand Billig returned then, with rain in his beard, and set down the saddlebags on the hearth.
"Ah, good," Kepler mumbled, "very kind." He put up his feet on the bags, offering his toes to the blaze: let the chilblains suffer a little too, and serve them right. "Yes, a wedding. Our dear Regina has gone from us. " He looked up into the Billigs' puzzled silence. "But what am I saying? I mean of course Susan. " He coughed, raking up an oyster. His head hummed. "The match was made in heaven, when Venus whispered in the ear of my young assistant, Jakob Bartsch, a stargazer also, and a doctor of medicine." And when the goddess had become discouraged, seeing what a timid specimen was this Adonis, Kepler himself had taken up her task. Pangs of guilt then, too. Such bullying! He wondered if he had done right. There was much of her mother in that girl. Poor Bartsch. "Young Ludwig, my eldest boy, also is going for medicine." He paused. "And neither have I been idle: another little one, last April, a girl," leering sheepishly at the fire. Frau Billig rattled the pots on the stove: she disapproved of his young wife. So had Regina. It would be a marriage, she had written to him, if my Herr Father had no child. A curious way of putting it. He had read much into that letter, too much. Foolish and sinful dreams. She was only hinting again about that damned inheritance. And he had replied that she might mind her own business, that he would marry when, and whom, he liked. But ah, Regina, what I could not say was that she reminded me of you.
Three times the name Susanna had occurred in his life, two daughters, one dead in infancy, one married now, and then at last a wife. Someone had been trying to tell him something. Whoever it was, was right. He had chosen her out of eleven candidates. Eleven! The comedy of it struck him only afterwards. He could no longer remember them all. There had been the widow Pauritsch of Kunstadt, who had tried to use his motherless children in plying her case, and that mother and daughter, each one eager to sell him the other, and fat Maria with her curls, the Helmhard woman who was built like an athlete, and that titled one, what was her name, a very Gorgon: all with advantages, their houses, their rich fathers, and he had chosen a penniless orphan, Susanna Reuttinger of Eferding, despite universal opposition. Even her guardian, the Baroness von Star-hemberg, had considered her too lowly a match for him.