The Science of Shakespeare (9 page)

Copernicus's book is an almost paradoxical mix of conservatism and innovation. Though he warned the pope of his “absurd” new theory, he also stressed, at every turn, its continuity with ancient thinking. Again and again, he references one or another ancient Greek philosopher; as Peter Dear puts it,
De revolutionibus
“was presented explicitly as a renovation of the ancient Greek astronomical tradition.” And as Heninger notes, “only in retrospect does he assume the role of an intellectual radical.”

*   *   *

Was the Copernican remodeling
of the heavens a seminal event that changed the course of history—or an academic exercise that changed nothing? We can certainly view it
today
as an earth-shattering—or more literally, “earth-moving”—event. Three cheers for the power of hindsight. But how was it seen in Copernicus's time? How big a splash did his theory actually make? To I. Bernard Cohen, writing in the 1980s,
De revolutionibus
was so unrevolutionary as to be barely worthy of notice: “The idea that a Copernican revolution in science occurred goes counter to the evidence … and is an invention of later historians.” He adds that the revolution that we usually associate with the name Copernicus is more properly attributed to the work of Kepler, more than half a century later. But philosopher Richard DeWitt, writing in the 2000s, assures us that, from the time of Copernicus's death to the end of the sixteenth century, “his theory was widely read, discussed, taught, and put to practical use.” Perhaps both are right: Copernicus's book marked only the first phase in the revolution; but certain people definitely took notice. It was hardly, as Arthur Koestler once described it, “the book that nobody read.”

A WORLD MADE FOR WHOM?

At least one aspect of the Copernican system was, in fact, revolutionary. His cosmos was truly vast: “So far as our senses can tell,” he wrote, “the earth is related to the heavens as a point is to a body and something finite is to something infinite.” That last word is tantalizing, though historians believe that Copernicus was unlikely to have imagined a literally infinite universe. Nonetheless, it was larger than anything the Western mind had had occasion to picture in the preceding centuries. One thirteenth-century astronomer had calculated that the most distant of the known planets, Saturn, lay some 73 million miles away—already “a staggering distance to the best-traveled medievals,” as one historian puts it, with the fixed stars, presumably, lying just beyond. Interestingly, because he accepted the ancient Greek value for the distance to the sun, Copernicus's estimate of the distances to the planets actually shrank the solar system compared with the Ptolemaic model. The distances to the stars, however, increased tremendously. The absence of stellar parallax meant that the stars had to be
much
more distant than in the medieval view.
*
By one estimate, the Copernican universe was larger than its medieval predecessor by a factor of four hundred thousand. This was an age when it was taken for granted that the universe existed for our benefit. What, then, occupied all of this empty space between the planets and the stars? What could be its
purpose
?

Decades later, when Galileo was writing his treatise on the competing world systems, he was conscious of this (by now familiar) objection. His book was written in the form of a dialogue, and he has the character Simplicio, the defender of the traditional worldview, tackle the “empty space” problem:

Now when we see this beautiful order among the planets, they being arranged around the earth at distances commensurate with their producing upon it their effects for our benefit, to what end would there then be interposed between the highest of their orbits (namely, Saturn's) and the stellar sphere, a vast space without anything in it, superfluous, and vain. For the use and convenience of whom?

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 thousand 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.