Galileo Read online

  Viviani’s encomium doesn’t stop there. His plaudits just go on and on. In a style very reminiscent of that of the first art historian, Giorgio Vasari, in his biographies of the greatest painters, Viviani writes that Galileo was a superb lutenist whose playing “surpassed in beauty and grace even that of his father.” This particular praise appears to have been at least somewhat misplaced: while it is true that Galileo’s father, Vincenzo Galilei, was a composer, lutenist, and music theorist, and that Galileo himself played the lute quite well, it was Galileo’s younger brother Michelangelo who was a true lute virtuoso.

  Finally, to top it all, Viviani relates that Galileo could recite at length by heart from the works of the famous Italian poets Dante Alighieri, Ludovico Ariosto, and Torquato Tasso. This was not exaggerated adulation. Galileo’s favorite poem truly was Ariosto’s Orlando Furioso, a rich, chivalric fantasy, and he devoted a serious literary work to a comparison between Ariosto and Tasso, in which he extolled Ariosto while brutally criticizing Tasso. He once told his neighbor (and later biographer) Niccolò Gherardini that reading Tasso after Ariosto was like eating sour lemons after delicious melons. True to his Renaissance spirit, Galileo continued to be deeply interested in art and in contemporary poetry throughout his entire life, and his writings, even on scientific matters, both reflected and were informed by his literary erudition.

  In addition to this splendid artistic and humanistic background, there were, of course, important scientific advances—a few genuinely revolutionary—that helped pave the way for the type of conceptual breakthroughs that Galileo was about to produce. The year 1543, in particular, witnessed the publication of not one but two books that were about to change humanity’s views on both the microcosm and the macrocosm. Nicolaus Copernicus published On the Revolutions of the Heavenly Spheres, which proposed to demote the Earth from its central position in the solar system, and the Flemish anatomist Andreas Vesalius published On the Fabric of the Human Body, in which he presented a new understanding of human anatomy. Both books went against prevailing beliefs that had dominated thought since antiquity. Copernicus’s book inspired others, such as philosopher Giordano Bruno and later astronomers Johannes Kepler and indeed Galileo himself, to expand the Copernican heliocentric ideas even further. Similarly, by elbowing out ancient authorities such as the Greek physician Galen, Vesalius’s book incentivized William Harvey, the first anatomist to recognize the full circulation of blood in the human body, to advocate the primacy of visual evidence. Major advances happened in other branches of science as well. The English physicist William Gilbert published his influential book on the magnet in 1600, and the Swiss physician Paracelsus introduced in the sixteenth century a new perspective on diseases and toxicology.

  All of these discoveries created a certain openness to science not seen in the earlier Dark Ages. Still, the intellectual outlook of even the most educated people at the end of the sixteenth century was predominantly medieval. This was about to change dramatically in the seventeenth century. There must have been additional factors, therefore, that were responsible for what we might call the “Galileo phenomenon.” Other things ought to have been radically revised to create the fertile ground that was eventually ready to receive Galileo and promote him to the status of protomartyr and an icon of scientific freedom.

  An important new sociopsychological element in the late sixteenth and early seventeenth centuries was the rise of individualism—the notion that a person can achieve self-fulfillment irrespective of social circumstances. This novel perspective manifested itself in areas ranging from the acquisition of knowledge to the accumulation of wealth, and from the determination of moral truths to the evaluation of entrepreneurial success. The individualist attitude was very different from the values inherited from the ancient Greek philosophy, in which people were considered primarily members of the larger community rather than individuals. Plato’s The Republic, for instance, aimed to define and help construct a superior society, not a better person.

  During the Middle Ages, individualism was prevented from taking root by the actions of the Catholic Church, through the principle that truths and ethics were determined by religious councils composed of a collection of “wise men” rather than by the experiences, contemplations, or opinions of freethinkers. This type of dogmatic rigidity started to crack with the rise of the Protestant movements, which rebelled against the assertion that those councils were infallible. Ideas espoused by the ensuing Reformation war penetrated other areas of culture. The war was waged not only on the battlefield and with propaganda pamphlets, one-page broadsheets, and essays, but also with paintings by artists such as Lucas Cranach the Elder, that contrasted Protestant and Catholic Christianity. It was partly the diffusion of these individualist convictions into philosophy that enabled the Galileo phenomenon. The same ideas were later put squarely center stage by the French philosopher René Descartes, who argued that an individual’s thoughts are the best, if not the only, proof of existence. (“I think, therefore I am.”)

  There was also a new technology—printing—that made possible both the individual’s access to knowledge and the standardization of information. The invention of movable type and the printing press in mid-fifteenth-century Europe had an immense impact. Literacy was suddenly not the preserve of a rich elite, and the dissemination of data and scholarship through printed books continuously increased the numbers of educated people. But that was not all. More people, from different walks of life, were now exposed to precisely the same books, leading to the establishment of a new information basis and a more democratic education. In the seventeenth century, students of botany, astronomy, anatomy, or even the Bible in, say, Rome could be using the same texts as their counterparts in Venice or Prague.

  The resemblance of this proliferation of sources of information to the effects and ramifications of the internet, social media, and communication devices today immediately jumps to mind. As an early precursor to e-mail, Twitter, Instagram, and Facebook, printing also allowed individuals to transmit their ideas to the masses more rapidly and efficiently. When the German theologian Martin Luther campaigned for church reform, he was assisted greatly by the existence of printing. In particular, his translation of the Bible from Latin into German vernacular, to represent his ideal of a world in which ordinary people could consult the word of God for themselves, had a profound impact on both the modern German language and the Church in general. About two hundred thousand copies in hundreds of reprinted editions appeared before Luther’s death. Similarly, no scientist at the time had a greater talent than Galileo for communicating his discoveries to others. Convinced that his message was ushering in a new science, he saw his role as that of the great persuader, and printing books in Italian rather than in the traditional Latin (which benefited only a few learned individuals) proved to be a potent tool to this end.

  Perhaps less obvious was the fact that printing also had an effect on mathematics. The ability to relatively easily reproduce diagrams, coupled with the printing of classical Greek manuscripts, renewed interest in Euclidean geometry, which Galileo was to make creative use of. Archimedes, the greatest mathematician of antiquity, would become his role model. Among many other achievements, Archimedes formulated the law of the lever and used it capably against the Romans in his legendary war machines. “Give me a place to stand, and I will move the Earth!” he was reported to have exclaimed. Galileo was only too happy to demonstrate that most machines could, at their basic principles, be reduced to something resembling a lever. Eventually he also came to believe in the Copernican model, in which the Earth was moving even without human intervention.

  More broadly, the recovery, fresh editing, and translation of texts from the classical past provided a basis for more skeptical, investigative, observational attitudes. The primacy of mathematics as key to both practical and theoretical advances was becoming apparent, and it burgeoned into Galileo’s guiding light. Mathematics proved essential in areas ranging from painting (where it wa
s used for working out vanishing points and foreshortening in perspective) to business transactions (where mathematician Luca Pacioli introduced double-entry accounting in his influential book The Collected Knowledge of Arithmetic, Geometry, Proportion and Proportionality). The upsurge in the numerical thinking of the time was perhaps best illustrated by an amusing anecdote involving Lord Burghley (William Cecil), the chief advisor to Queen Elizabeth I of England. According to this story, in 1555 he took the surprising step of weighing himself, his wife, his son, and all his household servants, and listing all the results.

  Finally, another factor that helped to enhance the reverberations of Galileo’s findings was the intense curiosity about newly discovered worlds brought about by the great explorers. Together with the geographical horizons, the span of knowledge also rolled wider starting with the last decade of the fifteenth century. Explorers such as Christopher Columbus, John Cabot, and Vasco da Gama reached the Caribbean islands, landed in North America, and found the sea route to India, respectively, just between 1492 and 1498. Then, by the 1520s, humans had circled the globe. No wonder that when the nineteenth-century French historian Jules Michelet tried to summarize the thirst for new wisdom and humanism that characterized the Renaissance, he concluded that it encompassed “the discovery of the world and of man.”

  A MAN OF HIS TIME AND BEFORE HIS TIME

  Galileo’s journey as a scientist started in 1583, when he dropped out of medical school and began to study mathematics. By 1590, at the age of twenty-six he already had the audacity to criticize the teachings on motion of the great Greek philosopher Aristotle, according to which things moved because of a built-in impetus. About thirteen years later, following a series of ingenious experiments with inclined planes and pendulums, Galileo formulated the very first “laws of motion” concerning free fall, even though he would not publish those until 1638.

  He presented his first breathtaking discoveries with the telescope in 1610, and five years later, in a famous Letter to the Grand Duchess Christina, expressed his risky opinion that the biblical language had to be interpreted in light of what science reveals, and not the other way around.

  In spite of his personal disagreements with some orthodox church dicta, as late as May 18, 1630, Galileo was still received in Rome as an honored guest by Pope Urban VIII, and he left the city under the impression that the Pope had approved the printing of his book Dialogue Concerning the Two Chief World Systems after only a few minor corrections and a change of title. Overestimating the strength of his friendship with the pontiff and underestimating the fragility of the delicate psychological and political position of the Pope in that turbulent post-Reformation era, Galileo continued to believe that reason would prevail. “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 once wrote. Imprudently neglecting his own safety, he proceeded to get the book to print, and, after a rather convoluted series of events, the book finally went to press on February 21, 1632. Whereas in the preface to the book Galileo purported to discuss the Earth’s motion merely as a “mathematical caprice,” the text itself had a very different flavor. In fact, Galileo taunted and derided those who still refused to accept the Copernican view in which the Earth revolved around the Sun.

  Einstein said about this book:

  [It] is a mine of information for anyone interested in the cultural history of the Western world and its influence upon economic and political development. A man is here revealed who possesses the passionate will, the intelligence, and the courage to stand up as the representative of rational thinking against the host of those who, relying on the ignorance of the people and the indolence of teachers in priest’s and scholar’s garb, maintain and defend their positions of authority.

  For Galileo, however, the publication of the Dialogo, as it is commonly referred to, marked the beginning of the end of his life, though not of his fame. He was tried by the inquisition in 1633, pronounced a suspected heretic, forced to recant his Copernican ideas, and eventually placed under house arrest. The Dialogo was put on the Vatican’s Index of Prohibited Books, where it remained until 1835.

  In 1634 Galileo suffered another devastating blow with the death of his beloved daughter Sister Maria Celeste. He still managed to write one more book, Discourses and Mathematical Demonstrations Concerning Two New Sciences (commonly known as Discorsi), which was smuggled out of Italy to Holland and published there in Leiden. The book summarized much of his life’s work, from his early days in Pisa, some fifty years earlier. Although his own travel was forbidden, Galileo was allowed to have occasional visitors. One of his callers during that late period of his life was the young John Milton, of Paradise Lost fame.

  Galileo died in 1642 at his villa in Arcetri, near Florence, after having been blind and bedridden for a while. But as we shall clearly see in this book, his science and the tale of Galileo and his times resonate strongly today. There is a striking similarity between some of the religious, social, economic, and cultural problems that a person in the seventeenth century had to struggle with, and those we encounter in the twenty-first century. Indeed, whose story is better to tell than that of Galileo if we are to shine light on current concerns such as the continuing debate about the proper realms of science and religion, the support for the teaching of creationist ideas, and the uninformed attacks on intellectualism and expertise? The blatant dismissal in some circles of the research on climate change, the mocking attitude directed at the funding of basic research, and the elimination of budgets for the arts and public radio in the United States are only a few of the manifestations of such assaults.

  There are additional reasons why Galileo and his seventeenth-century world are extremely relevant for us and our cultural needs. An important one is the apparent schism between the sciences and the humanities first identified and exposed in a 1959 talk (and later a book) by British physical chemist and novelist C. P. Snow, with his coinage of the term “the Two Cultures.” Snow presented his concern with great clarity: “A good many times, I have been present at gatherings of people who, by the standards of the traditional culture, are thought highly educated and who have with considerable gusto been expressing their incredulity at the illiteracy of scientists.” At the same time, Snow pointed out, had he asked those very same erudite essayists to define mass or acceleration—to him, the scientific equivalent of “Can you read?”—for nine in ten of the highly educated, he might as well have been speaking a foreign language. On the whole, Snow noted that during the 1930s and onward, literary scholars started referring to themselves as “the intellectuals,” thereby excluding scientists from this coterie. Some of those intellectuals even resented the penetration of scientific methods into areas not traditionally associated with the exact sciences, such as sociology, linguistics, and the arts. While surely not as extreme, their stance was not entirely dissimilar from the indignation expressed by church officials who reacted against what they regarded as Galileo’s unwelcome intrusion into theology.

  A few scholars argue that the problem of the two cultures is less acute today than it was when Snow gave his lecture. Others, however, claim that a proper dialogue between the two cultures is still mostly absent. Historian of science David Wootton, for example, feels that the problem has even deepened. In his book The Invention of Science: A New History of the Scientific Revolution, Wootton writes: “History of science, far from serving as a bridge between the arts and sciences, nowadays offers the scientists a picture of themselves that most of them cannot recognize.”

  In 1991 author and literary agent John Brockman introduced the concept of a “third culture,” in online conversation and later in a book with that title. According to Brockman, the third culture “consists of those scientists and other thinkers in the empirical world who, through their work and expository writing, are taking the place of the traditional intellectuals in rendering visible the deeper meaning of our lives, redefining who and wha
t we are.” As we shall see in this book, four hundred years ago, Galileo would have secured himself a place of honor in the third culture.

  The border between art and science was largely blurred during the Renaissance, with artists such as Leonardo da Vinci, Piero della Francesca, Albrecht Dürer, and Filippo Brunelleschi having been involved in serious scientific research or in mathematics. Consequently, Galileo himself embodied an integration of the humanities and the sciences that can serve as a model to be examined, even if not easily emulated today. Consider, for instance, that at age twenty-four, he presented two lectures on the topic of “On the Shape, Location, and Size of Dante’s Inferno,” or the fact that even Galileo’s science involved, to a great extent, the visual arts. For example, in his book The Sidereal Messenger (Sidereus Nuncius), a booklet of sixty pages that was rushed to print in 1610, he tells his scientific story of the Moon through a series of wonderful wash drawings, probably relying on the lessons in art he had received from the painter Cigoli at the Accademia delle Arti del Disegno (Academy of the Arts of Drawing) in Florence.

  Perhaps most important, Galileo was the pioneer and star of advancing the new art of experimental science. He realized that he could test or suggest theories by artificially manipulating various terrestrial phenomena. He was also the first scientist whose vision and scientific outlook incorporated both methods and results that were applicable to all branches of science.