by Dan Falk
Since the dawn of human thought, the universe was believed to have been made for us. The larger the universe became, the harder it became to sustain that belief. The wonders revealed via Galileo’s telescope would compound the problem, but already in 1580—when Galileo and Shakespeare were in their teens—the French writer Montaigne had ridiculed the idea of a human-centered cosmos. He wondered how mankind had come to believe that the cosmos exists “for his convenience.” Is it possible, he asked, “to imagine anything more laughable than that this pitiful, wretched creature—who is not even master of himself, but exposed to shocks on every side—should call himself Master and Emperor of a universe.…”
In Montaigne’s skepticism, and in Galileo’s hard-nosed reasoning, we see the dawn of a new way of thinking. We can also find this new perspective in the works of Shakespeare, as we will see. Removing our planet from the center of the universe, and setting it in motion, was the crucial first step. As Daniel Boorstin has put it, “Nothing could be more obvious than that the Earth is stable and unmoving, and that we are the center of the universe. Modern Western science takes its beginning from the denial of this commonsense axiom.” Already in the closing decades of the sixteenth century, the writing was on the wall: Faith was not immediately threatened by the Copernican universe—but it would certainly have to adapt. As Paul Kocher writes, the stakes could not be higher:
Was it still possible to believe that God made the world for man? Here lay the great question for Christianity as the geocentric gave place to the heliocentric universe. It was a highly complex question demanding no simple answer. Man’s uniqueness, the quality of God’s moral government of the universe for human good, the possibility of miracles, the authority of Scripture to teach truth about the physical world—these and many cognate issues all seemed at stake.
One of the defining characteristics of twentieth- and twenty-first-century science—one that would have been nearly unthinkable in early modern Europe—has been the idea that the universe was probably not made for our benefit after all; it simply is.* (Creationists, of course, reject such a view—but even secular liberals have trouble coming to terms with it.) One senses in Montaigne and Galileo—and, as we will see, in Shakespeare—the beginning of this profound change.
COPERNICUS’S UNIVERSE
Incidentally, the question of the universe’s size, and of our planet’s motion, are connected: The larger the former, the more plausible the latter. After all, why should the entire universe move about the Earth, if our planet is so minuscule? Or, as Copernicus phrased it: “How astonishing if, within the space of twenty-four hours, the vast universe should rotate rather than its least point!” The logic employed here goes back to ancient times, and involves an early version of “relativity”—not the Einsteinian sort, but rather the simple understanding that all motion is relative. Copernicus recalls Virgil’s description of a ship at sea. He quotes from the Aeneid: “We sail forth from the harbor, and lands and cities draw backwards”—surely the more reasonable inference is that it is the ship which is in motion rather than the lands and the cities. “No wonder, then, that the movement of the earth makes us think the whole universe is turning round.” Moreover, this larger universe hinted at the possibility of other worlds—or at least allowed for them. If our own sun harbored a family of planets, who could say how many planets might orbit other suns, at unfathomable distances from our own world?
In fact, the possibility of other worlds had been discussed often in the Middle Ages. Many medieval philosophers argued that an omnipotent God could have made as many worlds as he might have wished. Even so, the general consensus was that he only made one: our own blue-green world. (I’ve mentioned that list of heretical opinions issued by the bishop of Paris in 1277. Number 34 insisted, somewhat awkwardly, that the faithful concede that the Almighty could have created other worlds—but that no such worlds actually existed.) Nicole Oresme, a fourteenth-century French philosopher, considered the matter carefully, pondering the various mechanisms by which such worlds could be created, and where they might be located. In the end, however, he concluded, “But, of course, there has never been, nor will there be more than one corporeal world.” Even if De revolutionibus wasn’t met with panic in the streets—how many books are?—it indeed marked a turning point. As I. Bernard Cohen puts it, “the alteration of the frame of the universe proposed by Copernicus could not be accomplished without shaking the whole structure of science and of our thought about ourselves.”
It would be a half century before an inquisitive Italian scientist would aim a new invention, the telescope, at the night sky.* When he did—as we will see in Chapter 9—the wild Copernican “hypothesis” suddenly became plausible physical fact. But even without a telescope, the evidence against the ancient cosmological system was mounting. A crucial event—one that I played with in the Prologue, and mentioned briefly in the Introduction—unfolded in the autumn of 1572. In November of that year, a bright “new star” appeared in the constellation Cassiopeia, lighting up the night sky for the remainder of the year and through the next. Today we would call it a supernova, the explosion that takes place when a massive star exhausts its nuclear fuel supply and sheds its outer layers in a fiery burst of matter and radiation. The new star would come as an affront to the cosmology of Aristotle and Ptolemy. William Shakespeare was eight years old at the time—and a pompous Dane with a keen eye and a metal nose was twenty-six. After two thousand years, the ancient system of the world was beginning to show cracks in its very foundation.
3. “This majestical roof fretted with golden fire…”
TYCHO BRAHE AND THOMAS DIGGES
The story begins nine thousand years ago. Not in a galaxy far, far away, but in a relatively nearby section of our own Milky Way, located in the direction of the constellation Cassiopeia. Stars look pretty stable from night to night—even from century to century—but modern physics has revealed that stars actually take part in a continual tug-of-war between the forces of nature. Gravity strives to pull everything together; the energy produced by nuclear forces wants to blow everything apart. For most of a star’s life, it shines by burning hydrogen through a series of nuclear reactions in its core, and the balance between the forces is maintained. But this particular star—today it goes by the less-than-imaginative name of 3C10—was an old one, and it had already exhausted its supply of hydrogen.* When that happened, gravity became the dominant force, and the star, now containing mostly carbon and oxygen, began to collapse. Once, it had been a red giant; now it had evolved into a “white dwarf.” These dwarf stars are so dense that while they weigh as much as the sun, they are typically only the size of the Earth. (A lump of white-dwarf matter the size of a basketball would weigh about as much as an ocean liner.) Revolving in a mutual orbit with a larger companion star, 3C10 had been sucking hydrogen off of its neighbor, gaining mass in the process. This also caused the temperature in the core of the star to rise. Eventually, when its mass reached a bit less than one and a half times that of our sun, a new kind of reaction began: Carbon atoms were now fusing with each other, setting off an unstoppable nuclear chain reaction. A shock wave ripped through the star, radiating outward from the core, with a speed of more than ten thousand miles per second. The star exploded.
When it was a white dwarf, 3C10 had been much dimmer than the sun. Now it was a supernova, shining with the light of a billion suns. It would be—briefly—as bright as the rest of the galaxy combined. How many creatures, on how many planets, looked up and saw the spectacular death throes of this star? We don’t know—but we do know when they would have seen it. Light travels at 186,000 miles per second. If there happened to be a civilization a thousand light-years from the star, they would have seen the explosion a thousand years later (that is, about eight thousand years ago). Because 3C10 happens to be located about nine thousand light-years from earth, light from the exploding star took nine thousand years to reach our planet.* Photons from that initial burst of light, having traversed nine t
housand light-years of interstellar space, reached Earth in early November 1572. Before that moment, the remote nondescript star would have been invisible without a telescope (which had not yet been invented). Now, suddenly, it was as bright as the planet Venus.
* * *
Even before the light from 3C10 reached our planet, an inquisitive Danish nobleman named Tycho Brahe (1546–1601) had become hooked on astronomy. Tycho—like Galileo, he is remembered by his first name—was born in the province of Scania (today part of southern Sweden) three years after the publication of Copernicus’s revolutionary book. He was born into a powerful noble family who assumed he would eventually serve the king as a soldier or as an administrator. Raised by an uncle, he enrolled as a law student at the University of Copenhagen, but soon became distracted by events that unfolded in the heavens.
In 1559 and 1560 Tycho observed first a lunar and then a solar eclipse. Still a teenager, Tycho was stunned to learn that astronomers could predict solar eclipses months and even years in advance. A few years later, while studying in Germany, he witnessed a close pairing of Jupiter and Saturn in the sky (astronomers call it a conjunction), an eye-catching celestial coupling that occurs about once every twenty years. But Tycho noticed that the published tables, whether based on Ptolemy’s ancient system or the newer Copernican model, were inaccurate; the time given for the closest approach of the two planets was off by several days. Tycho became determined to improve on the existing tables; from that moment on, he would devote all of his energy to studying the night sky. Over the next few years he traveled widely within Europe, studying in various university towns and acquiring books and instruments as he went. In time, he became a master observer.
“A NEW AND UNUSUAL STAR”
But the most stunning celestial event—the one that cemented Tycho’s passion for astronomy and would end up changing the course of Western thought—came in the autumn of 1572, when the new star exploded into view in the northern sky. His travels behind him, Tycho was living in Scania, where he had built a small observatory on grounds owned by a relative. Tycho first spotted the star on November 11. (A handful of other European observers, it turns out, had seen it a few days earlier.) His excited tone was still in evidence months later, when he set his thoughts to paper:
Amazed, and as if astonished and stupefied, I stood with my eyes fixed intently upon it. When I satisfied myself that no star of that kind had ever shone forth before, I was led to such perplexity by the unbelievability of the thing that I began to doubt my own eyes.
Tycho studied the star’s appearance over several weeks; he also compared notes with other observers across Europe. He hurriedly wrote and published a short book describing his account of the event, called De Nova Stella (On the New Star). (The full title was actually De nova et nullius aevi memoria prius visa stella [Concerning the Star, New and Never Before Seen in the Life or Memory of Anyone].) His tone was not exactly modest:
I noticed that a new and unusual star, surpassing all the other stars in brilliancy, was shining almost directly above my head. And since I had almost from boyhood known all the stars of the heavens perfectly … it was quite evident to me that there had never before been any star at that place in the sky, even the smallest, to say nothing of a star so conspicuously bright as this.
The new star, appearing out of nowhere, was “the greatest wonder that has ever shown itself in the whole of nature since the beginning of the world.”
Unfortunately, new stars weren’t supposed to happen. It was an affront to Aristotelian and Ptolemaic cosmology, in which the heavens, by their very nature, were believed to be perfect and unchanging. How could one make sense of the appearance of a new star? One possible resolution was to imagine that it was actually a terrestrial phenomenon; perhaps it was located high in the Earth’s atmosphere. (Think of the momentary difficulty one has today in distinguishing a star from an airplane.) If it were shown to be “sublunar,” all would be well in Aristotle’s world. Yet if the new star were a “local” phenomenon, it would display parallax—in this case, meaning that it would be seen at slightly different locations (relative to the background stars) by observers at different locations on the Earth—or, indeed, by a single observer watching over an interval of several hours, because the Earth, as it rotates, would carry the observer over a distance of several thousand miles.* The moon, which traditionally denoted the boundary between the corruptible terrestrial region and the perfect realm of the stars, was known to display a parallax of roughly one degree. But Tycho’s new star showed no discernible parallax. In addition, it seemed to stay in the same location in the sky, relative to the other stars (displaying no “proper motion,” as an astronomer would put it). “I conclude,” Tycho wrote, “that this star is not some kind of comet or fiery meteor … but that it is a star shining in the firmament itself—one that has never previously been seen before our time, in any age since the beginning of the world.”
Fig. 3.1 Danish astronomer Tycho Brahe was among the first to see the “new star” of 1572 (depicted here above the “W” of Cassiopeia, and identified in Latin as “Nova Stella”). The star’s appearance challenged the Aristotelian picture of the universe, in which the heavens were imagined to be perfect and unchanging. The Bridgeman Art Library, London
Tycho was anxious to know what observers elsewhere in Europe thought about this strange and wonderful object. Thousands of people must have seen the new star, including dozens of professional astronomers, astrologers, and mathematicians. Many of them, like Tycho, rushed to get their observations into print. Among them was an English astronomer named Thomas Digges, one of the most important English thinkers of his day.
LEONARD AND THOMAS DIGGES
History has a funny way of allotting celebrity. Only the smallest handful of physicists and astronomers have come down to us as household names: Copernicus, Galileo, Newton, Einstein. From the next tier we have names like Tycho Brahe and Johannes Kepler—well known to those who have studied astronomy or taken a history of science course, but largely unknown to the general public. And then we have those who ought to be as well known, but, due to the vagaries of history, haven’t received their due. It is from this group that we find Thomas Digges (ca. 1546–1595). Digges was a military engineer and a member of Parliament—but that is not why he is remembered. Instead, we know him as one of the first English Copernicans, a man who gave us a new vision of the cosmos.
Science seems to have run in the Digges family. Thomas’s father, Leonard, was a distinguished mathematician who had studied at Oxford, where he developed an interest in problems of surveying—he invented the theodolite, for measuring angles—and in matters of defense. In 1555 he published an almanac, A Prognostication of Right Good Effect, which contained weather predictions as well as instructions for using various mathematical instruments for astronomy and navigation. It also included an outline of Ptolemy’s description of the cosmos. Another of his books, on surveying, remained in use for the next 150 years, going through at least twenty editions. Striving to speak plainly on all manner of practical problems in surveying, he complained of the many books on geometry “locked up in strange tongues.” He instructed his readers to go through the text once, and then a second time “with more judgement, and at the third reading wittily to practise” the various methods described, all in the aim of “profitable labour.” Incidentally, all of these accomplishments might never have come to pass had history taken a slightly different turn: In 1553, Leonard got caught up in what would become known as Wyatt’s Rebellion, a plot to overthrow Queen Mary. He was one of some five hundred alleged conspirators to be captured, tried, and convicted. But while the ringleaders were hanged—many were also drawn and quartered, for good measure—Leonard was among seventy-five men given a reprieve.
We know that Leonard Digges was intrigued by the night sky—but whether he gazed at it with the unaided eye, or had some kind of optical assistance, has been the subject of much debate. Did he invent a primitive telescope, and aim
it at the heavens? If he did so, it would have been a full six decades before Galileo—but the evidence is scant. We have only Thomas Digges’s account of his father’s use of “perspective glasses” for long-distance viewing; supposedly he could read the lettering on coins that had been scattered in a field, and could see what people several miles away were up to. Digges goes on to discuss the “marvellous” things revealed by the use of “glasses concave and convex”; he describes aiming such a perspective glass at a village, from some distance away, and being able to discern “any particular house or room thereof … as plainly as if you were corporeally present.…”
The claims seem to ask to be taken seriously, but many historians are doubtful. Richard Panek, for example, assures us that such instruments did not yet exist. “Despite their seeming certitude, these writings (and many others) were speculations or embellishments.” Richard Dunn describes the evidence as “uncertain,” but concedes that by this time “many people were making investigations with lenses of sufficient quality for a working telescope to be a practical possibility.” Thomas Digges, incidentally, says that he wrote a book on perspective glasses—but if he did, it has not survived, nor have any telescope-like devices from that period. (We will take a closer look at the plausibility of a “Tudor telescope” in Chapter 5.) Leonard Digges died when Thomas was just thirteen, at which point the younger Digges became a pupil of John Dee, one of the most influential philosopher-mystics of the age (and a figure we will look at in more depth in the next chapter). The two men would remain in close contact.