WHEN I FIRST STARTED TEACHING PHYSICS, THE STANDARD narrative was that modern science began with the heroic efforts of Galileo to gain acceptance for the revolutionary sun-centered worldview of Copernicus, as opposed to the ancient geocentric cosmology of Aristotle and Ptolemy accepted by academia and the Church. It was this crusade that sparked the Scientific Revolution and culminated in the new physics and astronomy of Newton, at the dawn of the modern scientific age.
Virtually nothing was said in this narrative about the predecessors of Copernicus, Galileo, and Newton, although historians of medieval European civilization have in recent years traced back the beginning of science in the West more than a millennium before them. In reality, an impressive succession of European scholars opened the way for the Scientific Revolution, laying the foundations for the breakthrough theories and discoveries later made some of which they anticipated.
Before Galileo seeks to right this historical injustice, something I started thinking about while studying physics in college. I did my undergraduate studies on the GI Bill after World War II at Iona College in New Rochelle, New York, founded by the Irish Christian Brothers. The first thing I noticed on the campus was a statue of Saint Columba, patron saint of the Irish Christian Brothers who lived in the sixth century. Columba had been forced out of Ireland and founded a monastery on the west coast of Scotland on the island of Iona, the legendary burial place of Macbeth. His students went on to found other monastic schools in England and then on the Continent, beginning the reeducation of western Europe in the Dark Ages, just as the Irish Christian Brothers who taught me had founded a college in a suburb of New York City, which they may have felt was in need of enlightenment. I certainly felt the need, for I had dropped out of school at seventeen to join the U.S. Navy, as had a number of my classmates.
My physics teacher at Iona was Brother Thomas Bullen, who had studied physics with P. M. S. Blackett, winner of the Nobel Prize in Physics in 1948. I knew that Blackett had studied at Cambridge under Lord Rutherford, the founder of nuclear physics, who was awarded the Nobel Prize in Chemistry in 1908. Rutherford in turn had studied at Cambridge with James Clerk Maxwell, the father of modern electromagnetic theory. Subsequently, with the aid of the Math-Physics Genealogy website, I was able to trace my scientific ancestry through Brother Bullen, Blackett, Rutherford, and Maxwell in an unbroken line that included Newton, Leibniz, Galileo, Copernicus, and on back to the first Greeks who graduated from Italian universities, and through them to George Gemistus Plethon, who graduated from the University of Constantinople circa 1375 and was the principal source in bringing Greek learning to Italy, giving rise to the Italian Renaissance. That the link was unbroken all the way to antiquity intrigued me. Who carried the torch in those dark years before Europe’s rebirth?
The most direct influence on this book, however, came from my postdoctoral study at All Souls College at Oxford with Alistair Cameron Crombie, renowned for his pioneering research in the history of medieval European science. After that, in addition to my courses in history and astronomy at what is now the University of the Bosphorus in Istanbul, I began teaching a course called The Emergence of Modern Science, East and West, a large part of which was based on what I had learned from Crombie, to which I have kept adding material on medieval European science up to the present day.
The principal idea that I inherited from Crombie was the continuity of western European science from the Dark Ages up through the times of Copernicus, Galileo, and Newton. More recent historians have questioned this notion. Thomas Kuhn’s The Copernican Revolution (1957) and The Structure of Scientific Revolutions (1962) emphasized the paradigm shift involved in the heliocentric theory as evidence of a discontinuity of post-Copernican science with the scientific tradition that had developed in western Europe during the Middle Ages. Kuhn certainly has a point, but as Crombie wrote of Copernicus in his Medieval and Early Modern Science, first published in 1952: “He is a supreme example of a man who revolutionized science by looking at the old facts in a new way.” Crombie goes on to point out the theories and data that Copernicus had inherited from his medieval European and ancient Greek predecessors, which is what I have done more thoroughly here, adding the contributions made by Islamic and Byzantine scientists.
Before Galileo begins with a look at western Europe at the beginning of the Dark Ages, with the Visigoth sack of Rome in 410 and the burning soon afterward of the great Library of Alexandria, with its vast collection of all the Greek works from those of Homer onward, as the ancient Graeco-Roman world was coming to an end in the gathering darkness of the early medieval period.
The Alexandrine Library contained copies of all the works of Greek science from the Pre-Socratics through the great mathematical physicists and astronomers of the Hellenistic period. Socrates himself wrote nothing, but he taught Plato, who in turn taught Aristotle, who taught Theophrastus, and so on, starting the chain of teacher and student, which was broken by the collapse of classical civilization and the burning of the Library in Alexandria, with the loss of all of their works.
But a number of the classics of Greek science and philosophy survived through a tenuous Ariadne’s thread that wound its way from Alexandria through the medieval Byzantine and Islamic worlds, involving, in the latter case, translations from Greek to Aramaic to Persian to Arabic, and then eventually into Latin.
Before these Latin translations became available in western Europe, only a few remnants of classical learning were preserved by increasingly isolated Roman scholars, most notably Boethius and Cassiodorus. But more substantial remains of classical learning made their way to the first Irish monasteries, principally those of Saint Columba, where a number of Greek-speaking scholars took refuge, crossing with him to Iona, beginning the reeducation of Europe and bringing light to the Dark Ages. Eventually this reeducation reached a high enough level for European scholars to understand Graeco-Arabic science in Latin translation, a process that accelerated with the founding of the first European universities in the twelfth and thirteenth centuries.
But in the earlier medieval period European scholars had to start literally from scratch, driven by curiosity and observation of the world around them and the heavens above. Thus in the process Western science had from the very beginning a quality of practical empiricism that distinguishes it from the more abstract character of most Greek and Islamic science. This is evident in the work of Newton who, as Crombie wrote, “achieved the clearest appreciation of the relation between the empirical elements in a scientific system and the hypothetical elements derived from a philosophy of nature.”
We will see this quality of practical empiricism of the Venerable Bede, writing in the early eighth century, who noted that “we know, who live on the shore of the sea divided by Britain,” how the wind could advance or retard a tide. Because of my early childhood in Ireland, I can relate to what Bede was saying. From age four to seven I lived with my mother’s parents out on the Dingle peninsula in county Kerry, the westernmost point of Europe, where life was governed by the tides. My grandfather Tomas, an illiterate Irish-speaking fisherman, was known as Tom of the Winds because his seeming endless knowledge of the world was said to have been brought to him by the four winds. I always went with Tomas when he set his nets on the strand near our cottage, from where we could hear the rumbling of the potato-sized rocks as they rolled in and out with the rise and fall of the sea, and he would wet his forefinger and raise it to gauge the direction of the wind before setting out. Tomas was my first teacher, and it may have been in my talks with him that I began thinking about things like time and tide that eventually led me to write this book. Whether you are a fisherman or a cobbler or a physicist, you need a teacher. That is what Before Galileo is all about—the transmission of knowledge from one person to another, which in the case of western Europe began during the long night of the Dark Ages, a thousand years before Galileo was born.
St. Jerome in his study, painting by Domenico Ghirlandaio, 1480