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  Kepler’s Witch

  An Astronomer’s Discovery of Cosmic Order Amid Religious War, Political Intrigue, and the Heresy Trial of His Mother

  James A. Connor

  with Translation Assistance by Petra Sabin Jung

  Truthfully I may confess

  that as often as I contemplate

  the proper order, as one results from another

  and becomes diminished,

  it is as if

  I have read a heavenly passage

  not written in meaningful letters

  but with the essential things in this world

  which tells me: Put your reason herein

  to comprehend these things.

  JOHANNES KEPLER,

  IN HIS CALENDAR FOR 1604

  Contents

  Epigraph

  Foreword

  With Thanks

  Introduction: So Why Kepler?

  Letter from Kepler to the Senate of Leonberg, January 1, 1616

  I With Unspeakable Sadness

  Where Kepler’s mother, Katharina, is accused of witchcraft by a former friend, which the gossip of the townspeople whips into a fury against her.

  Testimony of Donatus Gültlinger, Citizen of Leonberg, Given to Luther Einhorn, Magistrate of Leonberg, 1620

  Testimony of Benedict Beutelsbacher, German Schoolmaster of Leonberg, 1620

  II Appeired a Terrible Comet

  Where Kepler is born in Weil der Stadt, near Leonberg, including a description of the town, the Kepler family, and Johannes’s early childhood.

  Kepler’s Horoscope for Himself, November 1597

  III Born with a Destiny

  Where Kepler receives his education as a scholarship student under the care of the Duke of Württemberg.

  From Kepler’s Astronomia Nova, 1609

  IV Taken by a Forceful Passion

  Where Kepler enters Tübingen University and prepares for his calling as a priest of the Book of Nature.

  Letter from Kepler to the Theology Faculty at Tübingen, February 28, 1594

  V In Many Respects So Honorable

  Where a position as a mathematics teacher opens at the Lutheran school in Graz, and Kepler takes the position with some fear.

  Letter from Kepler to Michael Mästlin, February 10, 1597

  VI Married under Pernicious Skies

  Where Kepler publishes the Mysterium Cosmographicum, and in the following year marries Barbara Müller von Mühleck, a widow twice over with one daughter, which marriage is complicated.

  Letter from Kepler to Michael Mästlin, June 11, 1598

  Letter from Kepler to Herwart von Hohenberg, December 9, 1598

  VII An Archimedean Calculation of Motion

  Where the Lutheran community of Graz is persecuted, then banished, and where Kepler, who must choose between his faith and his position, is finally banished with them.

  From Kepler’s Eulogy on the Death of Tycho Brahe, October 24, 1601

  VIII When in Heaven the Flock of Secret Movers

  Where Kepler takes employment with Tycho Brahe and moves his entire family to Prague.

  Letters from Kepler to Johann Georg Brengger, October 4, 1607; November 30, 1607

  IX Living Creatures on the Stars

  Where Kepler writes the Astronomia Nova in Prague, a city full of magic and political intrigue.

  Letter from Kepler to Tobias Scultetus, April 13, 1612

  X Who with Tender Fragrance

  Where Kepler’s marriage is troubled, Rudolf II dies, and the Counter-Reformation comes to Prague in force.

  Letter from Kepler to an Unknown Nobleman October 23, 1613

  From Kepler’s Journal, 1614

  XI To Quiet the Gossip

  Where Kepler, after moving to Linz, Austria, must come forth to defend his mother on charges of witchcraft.

  Letter from Luther Einhorn, Magistrate of Leonberg, to the Duke of Württemberg, October 22, 1616

  XII If One Practices the Fiend’s Trade

  Where Katharina’s trial begins, and she is horribly mistreated, and where Johannes must leave the emperor’s service for a time to come to her aid.

  Letter from Kepler to Herzog Johann Friedrich von Württemberg, November 1620

  XIII With Present Maladies of Body and Soul

  Where the Thirty Years’ War begins with the Second Defenestration of Prague, and where Katharina Kepler is tried and convicted of witchcraft.

  From Kepler’s HARMONICE MUNDI, Book V, 1619

  XIV To Examine the Secrets of Nature

  Where Kepler writes his Harmony of the World as the Thirty Years’ War heats up, and where he is finally chased out of Linz, his home for fourteen years.

  Letter from Kepler to Johann Matthias Bernegger, February 15, 1621

  From Kepler’s Journal, 1623

  XV My Duty under Danger

  Where Kepler seeks a home for his last few years after fleeing Linz, argues with the Jesuits, finds patronage with Wallenstein, and dies in Regensburg

  Notes

  Kepler Time Line

  Source Readings

  Searchable Terms

  About the Author

  Copyright

  About the Publisher

  Foreword

  JOHANNES KEPLER is most often remembered for his venerable three laws of planetary motion, for which he has earned the title “the father of celestial mechanics.” But Kepler’s accomplishments were wide-ranging. In addition to acclaim for his laws of planetary motion, he is also considered the founder of modern optics. He was the first to investigate the formation of pictures with a pinhole camera, the first to explain the process of vision by refraction within the eye, the first to formulate eyeglass designs for nearsightedness and farsightedness, and the first to explain the use of both eyes for depth perception, all of which he described in his book Astronomiae Pars Optica. In his book Dioptrice (a term coined by Kepler and still used today), he was the first to describe real, virtual, upright, and inverted images and magnification (and he created all those ray diagrams commonly used in today’s optics textbooks), the first to explain the principles of how a telescope works, and the first to discover and describe the properties of total internal reflection. Galileo may have used the telescope that Johann Lippershey had invented to discover the moons of Jupiter and to see the first hints of Saturn’s rings, but it was Kepler who explained how the telescope works.

  Kepler probably was the first real astrophysicist, as we know the term in the modern sense, using physics to explain and interpret astronomical phenomena. He was the first to explain that the tides are caused by the moon. In his book Astronomia Nova, he was the first to suggest that the sun rotates about its axis. He wrote what may have been the first sci-fi story, a view of earth from the moon. In his book Stereometrica Doliorum Vinariorum, he developed methods for calculating the volume of irregular solids that became the basis of integral calculus. And he was the first to derive the birth year of Christ that is now universally accepted.

  Today when we think about scientists, we have images of university professors in ivy-covered halls, laboratories full of elaborate instruments, cadres of graduate students, laptop computers more powerful than all those used to send men to the moon, and large government grants. Yet with all of these resources, how much of today’s research will stand the test of time the way the works of Kepler have? Much has changed in four hundred years, but Kepler’s laws are as exact now as they were then. How was he able to accomplish so much? Actually, given the times he lived in and the meager resources, how was he able to accomplish anything?

  Context is the window to understanding. To understand Kepler and his accomplishments, one needs to understand the times in which he lived—the culture, people, places, politics, religion, a
nd his family. Wars, witch hunts, pestilences, and death were common everyday occurrences. The potions that people used as cures were a far cry from today’s medical miracle drugs. Kepler’s Witch communicates a feeling for the hardships, difficulties, rejections, loneliness, and heartbreak that Kepler endured. He lived on the verge of poverty. His salary was almost always in arrears. His only resources were paper, pen, and one man’s treasure trove of astronomical observations.

  What drove Kepler? What sustained him? How could he endure? It certainly wasn’t the money or even glory. He had few peers who even recognized his accomplishments. In Kepler’s Witch readers get a feeling for the source of his strength, his vision, and his perseverance, how he was able to do so much with so little in spite of all the evils that surrounded him in life. Kepler believed in an almighty God, the creator of heaven and earth. He believed in Jesus Christ as personal Savior. He believed in the ideal of the holy catholic (universal) church. Kepler was a man of peace in search of harmony—in particular, the harmony of the heavens. Somehow he knew it was there, even if life on earth was far from harmonious.

  David Koch

  National Aeronautics and Space Administration

  Deputy Principal Investigator for The Kepler Mission*

  *The Kepler Mission is a special NASA space mission for detecting terrestrial planets—that is, rocky, earth-sized planets—around other stars. It is scheduled for launch in 2006.

  With Thanks

  A BOOK like this one is a river, drawing from many sources. I owe thanks to each one and will name them, in no particular order except as they come to mind. First, great thanks to Petra Sabin Jung, who helped with the difficult task of translating Kepler’s German into modern English. Also, thanks to all my friends in Weil der Stadt: Dr. Manfred Fischer, the president of the Kepler Gesellschaft; Dr. Ernst Kühn, my sherpa guide up the steep slopes of Tübingen; Hubert and Elisabeth Bitzel, who were so kind and joined in my search for a Kepler sundae; Herr Bitzel, Hubert’s brother, the curator of the Kepler Museum, and a great Kepler fan; Dr. Wolfgang Schütz, the curator of the Weil der Stadt city museum, the town historian, and a wonderful source of information. Also, thanks to all the shopkeepers in the Marktplatz of Weil, who gave me samples. Thanks also to Anna Madsen and her father, Dr. Madsen, a Lutheran minister from Wisconsin. I met them both in Regensburg, and we had a wonderful little “Americans in exile” moment in the foyer of the Kepler Museum. Thanks to the people at the Sweet Home Hotel in Prague, who helped me get things mailed.

  Thanks also to my agent, Giles Anderson, of the Anderson Literary Agency; to my editors, Steve Hanselman and Mickey Maudlin, at Harper San Francisco; and to my publicist, Roger Freet—three men who made the Big Decisions. And thanks to Cindy DiTiberio, also of Harper San Francisco, who made all the other decisions. Thanks also to David Koch, Michael Gurian, Charles de Fanti and Leni Fuhrman, Malachy McCourt, John Anthony Connor, Margarette Alma Connor, William Craven, Sr., the New York Mets (for teaching me humility), and, of course, my wife, Beth Craven Connor, for teaching me everything else.

  Introduction: So Why Kepler?

  AFTER HAULING MY STACK OF LUGGAGE down the platform, I finally came across the last unclaimed seat on the night train from Stuttgart to Prague. Since no one shooed me away, I heaved my luggage into the upper bins and collapsed into the seat. Beside me were two Italian men who pretended to be asleep. Opposite them by the window was a blond German woman with a sack lunch on her lap. Beside her, in the middle seat, was a Korean boy, taller and lankier than I expected. He was traveling around the world, and in his broken English he said he wanted to know everyone’s story. Across from me was a short, unnaturally thin German student with a buzz cut and an excess of earrings, sitting wound into himself in a sort of existential fetal position. I was not surprised when he pulled out a packet of cigarette papers and rolled his own.

  “You an American?” he asked.

  “That’s right.”

  “So what are you doing in Germany?” he went on, as if I alone had no right to be there.

  “I’m writing a book about Johannes Kepler.”

  “What makes you think we want to know what you have to say about Kepler? You cowboy Americans and your cowboy wars. How many people have you killed this week?”

  He watched me, waiting for me to bite. I wanted to explain to him about World War I and World War II, but I didn’t think this was the time. “Well, we were attacked, you see,” I said finally. “I was just across the river in Jersey at the time, so I saw it myself. So don’t talk to me about our ‘cowboy wars.’”

  The temperature in the compartment dropped considerably. People fidgeted and looked at one another nervously, wondering if there was going to be a shouting match. Discussing American foreign policy is only pleasant under the most controlled conditions, especially since I didn’t agree with the policy myself, though I wasn’t going to tell him that. The student leaned back in his seat, muttered “cowboys,” and pulled out a well-thumbed pocket edition of sayings from the Qur’an. For the next two hours, the trip rolled along pleasantly enough. The Korean student talked about his hometown and then all about the countries he had traveled through, counting them all on his fingers. The Italian men said they both came from Belluno, a city just north of Venice. The German woman spoke briefly, in German. One of the Italian men translated for the rest. She was on her way to visit her son, who was staying with his father, her estranged husband, who was in turn staying with his mother. Though they were not divorced, she worked and lived in Frankfurt, and her husband lived in a little town outside Berlin.

  Suddenly, the student tucked his copy of the Qur’an back into his pocket and cocked his head at me.

  “So why Kepler?” he said.

  I looked at my shoes and thought about how to answer him. After a while, I looked up and said, “Because in 1620 Kepler’s mother was being tried for witchcraft. Germany was well into the Thirty Years’ War. Kepler had already lost his first wife and little boy to disease, and in the years following he lost three more children. In his adult life, he was chased out of one town after another by the Counter-Reformation. He was excommunicated by his own church. And yet, throughout most of these years he was writing a book called The Harmony of the World. This,” I said, “is a man worth knowing.”

  The German student eyed me and sucked on his cigarette.

  Since then, I have thought a good deal about this question. Great people show up now and then in this world. What makes them great is complicated. Some say Kepler was a genius, which he certainly was, but his scientific intelligence was not the source of his greatness. Johannes Kepler was one of the most powerful scientific minds of his century—he was an equal to Galileo in almost every way, a precursor to Newton, a man who had done the spadework for most of the important discoveries that defined science in the seventeenth century. And yet Kepler was also great in the way Gandhi and Martin Luther King, Jr., are great. He was a man who fought for peace and reconciliation between the Christian churches, even when it nearly cost him his life. Some people are born to greatness; some are made great by the events of their day. Some, such as King, Gandhi, and Kepler become great because they make choices full of moral courage. Kepler was a believing Lutheran and would never become a Catholic, even when it would have benefited his career to do so. People all around him were jumping from one church to another. Kepler’s father-in-law did it. So did many of his acquaintances and rivals, simply to better their political or social position or not lose their earthly possessions. But Kepler believed in the Reformation; he believed in it with his soul. He stood fast with the Lutheran church, even when that church excommunicated him. When the Counter-Reformation chased the Lutherans out of their homes, he went with them, all the while fighting with the leaders of his own church in order to maintain the integrity of his conscience.

  This book is a response to the question that the German student posed so succinctly—“Why Kepler?” Kepler is the man who finally confirmed Copernicus. He made a
first, close attempt at defining a law of gravity. But above that, he was a man who contemplated in mathematics the glory of God. His life, his work, his mathematics were always about God. Everything he did was about God. Kepler found God in the hidden mathematical harmonies of the universe in as deep a way as he found God in the revelations of Scripture.

  This is a man worth knowing. This book places him in his world, in his faith, in the events of his day. So why is Kepler not better known in our world? Everyone knows Galileo, even if all they know is that he was the guy who fought with the pope. Most people at least know the name Copernicus and that he had something to do with a revolution. They know Newton as the guy who had an apple fall on his head. But many Americans do not even know Kepler’s name; it’s as if he has been written out of the history of science. The National Air and Space Museum in Washington, D.C., has almost nothing about him. Why? Kepler was, as author Arthur Koestler called him, the “watershed” where the medieval world finally gave way to the modern. After Kepler’s time, the scientific movement codified its method, largely following the lead of Newton’s Principia. Newton, whether by accident or design, kept his own personal thoughts and mystical speculations, of which he had many, out of his scientific writing, a practice that later became the model for the scientific mind-set—distant, observing, uninvolved.