God In The Equation Read online

  But by the end of the nineteenth century, the human exploration of the heavens had reached an impasse. Our measuring sticks weren't long enough to assess the extent of God's domain. In fact, parallax gave accurate results only for the closest stars. Beyond that, the effect became imperceptibly minute. It gave only vague hints about the extent of our galaxy, and it told nothing about the spiral nebulae that Herschel believed were mighty whorls of stars in their own right. Without that information, speculation about the nature of the spiral nebulae remained speculation alone. The situation changed little for the better part of a century: at the end of World War I, astronomers were still engaged in a debate about the scale and structure of the universe. Newton had formulated mathematical laws whose reach seemed infinite, but at the end of the nineteenth century his successors were still struggling to understand the lay of the land in their galactic backyard. What lay beyond was a mystery, a no-man's-land denied to science. Astronomers were similarly limited in their ability to explore across heavenly time. By declaring the cosmos eternal, Newton essentially declared the whole question of origin and first causes as off-limits to scientific inquiry. His theory of universal gravitation didn't lead to universal enlightenment.

  Undeterred, scientists carried out their quest for the spiritual by investigating mysteries closer to home. They couldn't trace the origin of an eternal universe, for instance, so they started trying to measure the age of the Earth. In the Book of Genesis, the origin of the Earth and the origin of the universe are part of the same, week-long episode of divine creation. During the medieval and early modern periods, Catholic theologians had investigated the biblical chronology in fine detail. Saint Augustine examined the rate of progress in human history and concluded that the beginning of the world—but not, of course, the beginning of God—occurred around 5000 B.C. The most notorious age measurement came from James Ussher, the archbishop of Armagh, Ireland, in 1650. In an unwitting act of reductio ad absurdum, he placed the creation of the Earth on the evening before October 23, 4004 B.C. The growing power of science meant that the Earth's history could now be submitted to a different kind of calculation.

  Herschel's sky surveys suggested that stars might condense from clouds of luminous gas. Later, in the 1840s, the German philosopher and scientist Hermann von Helmholtz formulated the concept of conservation of energy and argued that the sun's heat must derive from gravitational energy that is liberated by its contraction. In other words, the sun shines because it is constantly falling in on itself. This effect—which in fact does apply to young stars in the first stages of formation—offered a way to calculate the age of the sun and, by extension, of the Earth. If the sun began as one of Herschel's clouds, then it was a simple matter of mathematics to determine how much gravitational energy resides in such a cloud and how long that energy could keep the sun shining. Helmholtz's friend Lord Kelvin, one of the most influential scientists of the latter half of the nineteenth century, followed through on this work. In 1863 he declared the Earth to be less than two hundred million years old, a number that he steadily revised downward in later years.

  From a cosmological standpoint, the crucial point is not that Kelvin was wrong, but that he so boldly insisted the age of the Earth could be determined through scientific inquiry. And although he never presumed to speak about the age of the universe, his increasingly emphatic calculations of when our planet formed undermined the Newtonian belief that God's glory is reflected in the permanence of his creation. Helmholtz, meanwhile, began looking in the other direction and staking science's claim on the future. Working from Kelvin's ideas about the dissipation of heat, Helmholtz anticipated that all of the energy powering the stars would someday be depleted. He spoke despairingly of the endless decline “which threatened the universe, though certainly after an infinite period of time, with eternal death.” But he still did not dispute its eternal existence.

  In the 1850s, just as Helmholtz was bemoaning our cosmic future, two other researchers were testing the limits of another of Newton's signature concepts, the cosmic uniformity of natural law. Newton's equations of gravitation seemed to apply anywhere in the universe, contradicting Aristotle's old notion that the ether follows different rules from those governing the common elements. Now the German physicists Gustav Robert Kirchhoff and Robert Bunsen had found a way to see if celestial objects are composed of the same elements, built from the same kinds of atoms, as the Earth. Earlier research had shown that when sunlight passes through a fine prism, the resulting spectrum is full of thin dark lines; conversely, elements heated by a carbon-arc lamp produced thin spectral lines of light in an analogous pattern. Kirchhoff put the pieces together and concluded that the dark absorption lines in sunlight are just the emission lines seen in silhouette. Together with Bunsen, he started examining the solar spectrum for the spectral fingerprints of familiar elements. Within a few years they identified thirty common elements, behaving in the sun just as they do on the Earth.

  Starting in 1862, Sir William Huggins, a British astronomer blessed with enough wealth to afford his own observatory, extended this work to the stars and found the same atomic absorptions there as well. When he trained his telescope on the nebulae, he again saw the chemical signatures of known elements, but this time as emissions, not absorptions—a distinction showing that the nebulae consisted of thin gas at low pressure. “The answer, which had come to us in the light itself, read: Not an aggregation of stars, but a luminous gas,” he recalled excitedly. This finding later caused some confusion, as it obscured the distinction Herschel had made seventy years earlier and seemed to suggest that all nebulae are nothing but wisps of vapor. For the moment, however, these results were both revelatory and reassuring. “A common chemistry, it was shown, exists throughout the universe,” Huggins wrote. Newton's faith in uniformity was vindicated. The reach of the astronomers extended again, such that they could reply to the poets and tell them what stars are made of.

  Yet Newton didn't lead science into the promised land, nor did Huggins. Both men suffered from limits of vision. For Huggins the problem was literal: he could not study what he could not see, and spectroscopy demanded a lot of light. For Newton the problem was too much of that old-time religion. He could not bring science into the farthest reaches of space because he was shackled to his faith in an infinite universe and absolute space, which he regarded as necessary attributes of an omnipotent God. Albert Einstein, Newton's heir and one of his few intellectual rivals, did not carry this theological baggage. Newton had to rely on God to provide a reference against which to measure time and location; Einstein derived equations that gave shape to space all by themselves. Newton's theory of gravity required divine intervention to keep it both endless and eternal. In seeking a more comprehensive description of gravity, Einstein redrew the universe, melding Newton's devotion to inviolable, all pervasive laws with the geometric beauty of Aristotle's spheres. This new universe was finite, spherical, static, and eternal. It was the heavenly vision that heralded the birth of the new faith, sci/religion.

  In creating his radical cosmology, Einstein stitched together a rational mysticism, drawing on—but distinct from—the views that came before. Galileo had tried to define a line of demarcation between science and religion by insisting that the Bible tells how to go to heaven, not how the heavens go. Einstein endlessly violated that boundary by redefining God both as an ally and an end in his search for scientific truth. “God does not play dice with the universe,” and “the Lord God is subtle, but malicious he is not” are just the most famous of Einstein's sci/religious declarations. His deity was not the interventionist God of Abraham and Isaac, but something more complex and abstract—not so much the Creator of the universe as the embodiment of a beautiful and economical set of physical laws. Einstein snatched the deist God of Spinoza and impressed Him into duty for science. This God does not dictate to His human subjects. Rather, they dictate to Him through their scientific investigations. Einstein built on the process begun when Newton insiste
d that his Creator would take care to place the stars sufficiently far apart to avoid gravitational disruption. God embodies cosmic law, and cosmic law is revealed through what comes out of the equation and the eyepiece.

  Einstein believed the path to God lay in understanding the way the universe works today, not how it began. Initially he didn't consider a beginning at all, again following in the tradition of Newton and Aristotle, yet his ideas provided the underpinning for the grandest, most persuasive creation story ever told. First came the big bang theory. More recently, cosmologists have started proposing an endless succession of bangs and, in an echo of Saint Augustine, arguing that the beginning of our universe was not necessarily the beginning of time. What all the modern scientific thinkers have in common is a faith that scientific inquiry lives where religion once ruled, back to the moment of creation. They are all driven by a holy conviction that they are on a quest toward absolute cosmological truth and that mathematical unity, consistency, and beauty will lead them there. They all seek the missing elements needed to elevate the known physical laws into a comprehensive model of the state of the universe. They have even resurrected Einstein's Lambda to perform that task. Ask them if they believe in religion and nine times out often they will profess a careful agnosticism. Examine their research, however, and it will leave no doubt that they worship in the Temple of Einstein.

  Of course, any attempt to understand this world necessarily has a subjective human element—at the very least, an element of faith in the comprehensibility of the natural world. How else could Eudoxus believe that his geometry would allow him to mimic the movements of the planets? How else could Newton believe that the same gravity that holds us onto our planet reaches to the farthest star? What keeps changing is the scale and the stakes. Copernicus, with some help from Galileo and Kepler, exiled us from the motionless center and opened the possibility that human inquiry could extrapolate from the Earth to the heavens. Newton codified that idea with his laws of universal gravitation. Einstein brought all of the universe—not just its function, but also its form—down to Earth in his field equations. The result is an inevitable theological turnabout, in which God began to take man's image. Even that devout-sounding sentence “God is subtle, but malicious he is not” presumed that it lay within Einstein's power to infer or decree divine intent.

  We've been headed this way since the days of the Greek academies. It was like an ancient prophecy that finally became clear when Einstein arrived: When we reach for vastness it is like grasping for the Divine. We are a small huddle of life clinging to a moist blue rock that swings endlessly around a modest yellow star on the outskirts of a galaxy floating among billions of others. We evolved to hunt for food, to make simple tools, to find mates and have sex. Along the way we also evolved consciousness and a desire to know, and it got wired deep in the brain along with our other instincts. We crave an understanding of our place in the world. Once we sought that through Scripture. Many people, in many parts of the world, still do. Increasingly, however, they are finding the ecstasy lies elsewhere. Einstein put God in physics and made physics into God.

  3. THE TEMPLE OF EINSTEIN IS FOUNDED

  IN THE EARLY WINTER months of 1917, Albert Einstein huddled in his bachelor's flat at Wittelsbacherstrasse 13, in central Berlin, and prepared to reshape our deepest insights and our everyday ideas about the physical workings of the world. Gallstones shot pain through his abdomen, and the war-reduced Prussian diet disagreed with his sensitive stomach, but his mind was elsewhere. Each stroke of his pen conjured up a strange new place where light bends like taffy and galaxies float atop a sea of curved space, like ships scattered across the global expanse of the Earth's oceans.

  Einstein was no longer the boy genius who formulated his theory of special relativity at age twenty-six while laboring as a technical officer at the Swiss Patent Office in Berne. Now thirty-seven, he had achieved indelible fame within the scientific community, although he was still not quite a household name. Recognition did not make his labors any easier. For years he had struggled to broaden his theory of relativity into a set of equations that would explain the fundamental nature of gravity and the structure of space, a task that had eluded even the great Newton's intellectual grasp. He endured painful setbacks and repeatedly scrapped his

  in finally delivered his general theory of relativity. He had taken another leap forward in his determined journey toward unlocking the secrets of the universe and thereby entering the mind of God. This was, he wrote to physicist Arnold Sommerfeld, “the most exacting period of my life; and it would be true to say it has also been the most fruitful.” Crafting general relativity was the biggest challenge he had ever tackled. He compared it, in a letter to his friend Paul Ehrenfest, to “a rain of pitch and sulfur.” The work exhausted him, both physically and intellectually. But it led to one of his most profound discoveries. According to his new elaboration of relativity, gravity warps the structure of space. Newton had hit a dead end when he tried to understand how gravity links bodies through the emptiness of space, essentially relying on God to transmit the attraction responsible for action at a distance. Einstein hit on a new formulation: Space and matter are equal partners, with gravity the result of the interaction of these tangible and intangible elements. This result soon led to a second, inspired break with Newton, in which Einstein abandoned the infinite universe so that he could embrace all of space with his equations. Considering the universe as a whole, Einstein realized the collective warping would cause space to curve in on itself, forming a giant ball. Like the surface of the earth, this spherical universe was limited in extent but had no edge.

  When he scrutinized cosmic implications of the theory, however, Einstein found one aspect of the result disturbingly wrong. The finite universe described by general relativity inclined either to expand, carrying all the stars away from one another, or to collapse disastrously under the force of gravity. Here Einstein remained rooted in the classical conception of Aristotle and its Newtonian echo: the universe is eternal and unchanging, how else could it be? So the great man shrugged, again took up his pen, and added an extra component—the cosmological constant, represented by the Greek letter lambda—into the mathematics describing the way space and matter interact. Lambda gave empty space an outward pressure that could precisely negate the inward pull of gravity. Once again the universe was static, exactly the way God would have made it.

  In this simple act, Einstein breezed past the tradition of Copernicus and Galileo, establishing a vastly expanded domain for science. Now its scope included not only all the observable phenomena of nature, but also the master framework of the universe within which all those phenomena occurred. And by embracing all of physical reality, Einstein was no longer content to have science praise the ultimate glory of God, as Newton had been. General relativity seemed ready to tackle everything that is out there. If so, science was no longer restricted to describing God's handiwork; now it could describe God. Einstein popularized this conception through his widely reported comments about the nature of God and about what God would or would not do. But the new attitude would have come across even without Einstein's proselytizing. Simply by putting Lambda into his relativity equations, he implicitly claimed that he could draw on the authority of modern science to discern the structure of the universe and, by extension, the nature of its Creator.

  It was a long journey from Einstein's famously unpromising childhood to his adult role as shaper of the universe. He was born on March 14, 1879, to Pauline Einstein (nee Koch) and Hermann Einstein in an unremarkable apartment in the German town of Ulm. His father was an optimistic but repeatedly unsuccessful entrepreneur who dabbled in ventures selling goose down, manufacturing boilers, and installing electric lamps—ventures that, for a while, at least, kept the family in a comfortable, middle-class existence in Munich, where the family moved when Albert was one year old. “Nothing in Einstein's early history suggests dormant genius,” writes Ronald Clark, one of Einstein's most perceptive biogra
phers. If anything, the signs pointed the other way. Stories of the young Albert as a backward child, poor at language, have become a standard part of the Einstein legend. They come predominantly from Einstein himself, who recalled his sluggish early development as something of a blessing in disguise: “The normal adult never stops to think about the problems of space and time. These are things which he has thought of as a child. But my intellectual development was retarded, as a result of which I began to wonder about space and time only when I had already grown up.”

  The formation of Einstein's peculiar brand of deism seems easier to trace, although the amount of information about his early religious views is limited. His parents were Jewish, but they rejected most aspects of Jewish practice, and the young Albert attended Catholic school and lived in a predominantly Catholic region. At age eleven, he had absorbed sufficient mixed religious instruction that he stopped eating pork and composed private hymns. While he was studying at the strict Luipold Gymnasium, however, Einstein entered a rebellious phase and his thinking started to shift. Soon he was reading scientific texts and Kant's Critique of Pure Reason. Despite, or because of, his continuous religious instruction, he became convinced that “much of the stories of the Bible could not be true.” He never had a bar mitzvah ceremony. Later in life he looked back at his childhood religious phase as “a first attempt to liberate myself from the 'only personal.'”