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Copernicus: A Drama for Our TimeA More Perfect Heaven: How Copernicus Revolutionized the Cosmos by DavaSobel (2011) Walker & Company, New York

2012; Wiley; Volume: 26; Issue: 3 Linguagem: Inglês

10.1096/fj.12-0302ufm

1530-6860

Margaret J. Geller,

Historical Astronomy and Related Studies

Copernicus is an icon for revolutionary change in our perception of the universe. In her book, A More Perfect Heaven: How Copernicus Revolutionized the Cosmos, Dava Sobel shows us a very human Copernicus, a remarkable man living in a tumultuous time. His story unfolds in the early 16th century, but it is a tale for our time. Copernicus was fortunate to have unusual access to high-level education. His father died when he was young, and a generous uncle, who became Bishop of Warmia (a region in northeastern Poland), shepherded his education. His romance with the skies began when he was young. At the Jagellonian University in Krakow, Copernicus studied the motions of planets and purchased a table for calculating their positions. Years later, he wrote, “For what could be more beautiful than the heavens, which contain all beautiful things?” This disarming and deceptively simple question motivates exploration of the universe today, just as it did in Copernicus' time. Copernicus' uncle was a practical man who encouraged his nephew to study canon law and medicine. This broad education honed Copernicus' stunning intellectual talents and later made him indispensable to the religious administrative hierarchy in Warmia. Copernicus became a canon; he was a personal physician to bishops, and he was an effective administrator of the land holdings and businesses of the bishopric of Warmia. By the age of 37, he had a house, two servants, and three horses. He could spent his spare time understanding ancient observations of the planets, making his own naked-eye observations much in the tradition of those before him and thinking about a system to link it all elegantly together. By 1510, Copernicus had made the leap to a heliocentric system with a spinning earth orbiting the sun. He distributed a Brief Sketch describing his model. As Dava Sobel tells this part of the story, Copernicus pulled these ideas from thin air. This remarkable intellectual breakthrough is one of the great mysteries of the Copernicus story or perhaps of any story in great changes in our understanding of nature. Although the entire picture of a sun-centered solar system belongs to Copernicus, there were philosophers who had moved the earth before. Aristarchus (310 B.C.E.–230 B.C.E.) postulated a sun-centered system and a universe of distant, fixed stars. In the first half of the 15th century, Nicholas of Cusa, a philosopher well ahead of his time, speculated that the earth was not at rest, that its poles were not fixed, and that the difference between this idea and appearances resulted from relative motion. Nicholas of Cusa was certainly known in Padua, where Copernicus studied later. Of course, we will never know, but it is interesting to wonder whether the musings of this earlier philosopher influenced Copernicus. Copernicus' time was a period of change and tumult. The Teutonic Wars literally reached Copernicus'doorstep in 1519 and destroyed the observing platform he had built outside of the cathedral of Frauenburg, where by then, he had an apartment. It was a time of violence and of changing ideas. Martin Luther was threatening the Catholic hegemony. At the same time, the way people looked at the world around them began to change to a more hands-on approach of observation and measurement. New ideas traveled around Europe. By the beginning of the 16th century, books were available to the upper-middle class and the wealthy. Couriers on horseback carried mail, albeit it slowly, throughout Europe. People in far-away places thus knew about Copernicus' investigations. The drive to understand nature was as international then as it is now. Although the young Copernicus had the courage to write a sketch of his model, the older man eschewed further publication. He worked assiduously on a book documenting his work, but he feared that ridicule or even censure would greet publication. By 1535, his book was essentially complete, and his friend and confidant Tiedemann Giese (eventually Bishop Giese) encouraged him to publish, to no avail. Dava Sobel tells the story of the ultimate publication of On the Revolutions of the Heavenly Bodies as the drama it was. To accomplish this feat, she inserts a play in the middle of her narrative. The play is an effective device for making Copernicus and his contemporaries human. The artistic license Sobel takes is a refreshing way to transport the reader into the 16th century. It is almost possible to hear the voices ringing in the cold halls. The contrast between the humanity and emotion of the play and the rather dry, scholarly text of the rest of the book makes the reader think deeply about the importance of coincidence in life and about the transcendent power of ideas. One of several great coincidences in Copernicus' life was the arrival of Georg Joachim Rheticus, a young German Lutheran mathematician. Rheticus arrived at Copernicus' home in Frauenberg bringing gifts and hoping to study astronomy with the great man. We will never know exactly why Rheticus arrived. We will never know how he convinced Copernicus to publish. We only know that the climax of his 2-year-long visit was Rheticus' delivery of Copernicus' six-volume manuscript in 1542 to the printer Petreius in Nuremburg. The timing of Rheticus' visit was nothing short of miraculous. Copernicus died in 1543, and legend has it that he saw the printed pages of his book just before he drew his last breath. The scholarly discussion in A More Perfect Heaven makes challenging reading, but the play alone (it is well worth reading these pages on their own) prompts thinking about what would have happened had Rheticus not arrived. We might never have heard of Copernicus. His Brief Sketch would have added to the collection of suggestions by Aristarchus and Nicholas of Cusa. Someone else would have made the synthesis that we call the Copernican Revolution. Copernicus moved the earth, but he did not abandon the classical idea that the paths of heavenly bodies were circles. As a result, he was still stuck with Ptolemaic epicycles (circles moving on circles) to account for the orbits of the planets. Johannes Kepler, who richly annotated his own copy of On the Revolutions, recognized that the orbits are ellipses. In the early 17th century, Galileo invented the telescope and proved that the sun-centered model is correct by using his new instrument to discover the phases of Venus. They cannot be explained in an earth-centered system. Newton, born the year after Galileo died, developed his theory of gravity to explain the motions of the planets in a fundamental way. In the early 20th century, Einstein's theory of general relativity accounted for the detailed orbit of Mercury, and finally, the dance of the planets was understood. A moving earth required a larger universe. Copernicus recognized that the stars had to be far away; otherwise, they would appear to move as the earth traced out its orbit around the sun. Copernicus not only displaced people from the center of their universe, but he also made the universe bigger. Today, we know that we live in a mind-bogglingly, vast universe. The portion of it that we can explore extends for some 13.7 billion light years, the distance light has traveled since the big bang. At the beginning of the 20th century, when Einstein developed his theory of general relativity, many still thought the sun was at the center of our galaxy, the Milky Way. Now, we know that we live in the suburbs of the galaxy and that it is one of many distributed across the evolving, stretching space of a universe that has no center. The technology that enables our complex, interconnected modern lives also enables exploration of the vast space we inhabit. The journey is a voyage of the imagination, guided by the physical laws that we discover and test in laboratories on the earth. In a 10-day exposure, the Hubble Space Telescope revealed the farthest reaches of the visible universe (watching the voyage through the image at http://hubblesite.org/gallery/tours/ is an inspiring accompaniment to Sobel's book) when galaxies like our own were only 1 billion years old. This image, called the Hubble Ultra-Deep Field, is a measure of the reach of the human mind. We are linked to Copernicus by our curiosity and our drive to understand the universe, our origins, and our place in it. Like Copernicus, we ask questions about the universe, and like Copernicus, we are able to answer some of them. The story of Copernicus shows how the answers change us. To some, the sun-centered solar system diminished humanity by removing us from an apparently privileged, central position in the universe. Modern cosmography continued that process as our blue dot became a tinier and tinier speck in the immensity of the universe. A grander vision of Copernicus' impact is that he pioneered the way toward models of the universe based on mathematics, observation, and testable physical theories. This scientific approach has been enormously successful, not only in the practical enrichment of our lives but also in extending our intellectual reach in a thrilling, awe-inspiring way from subatomic particles to the farthest reaches and earliest epochs of the universe. Dava Sobel's book reminds us that we are special because we wonder and because we are driven to understand the universe.