How We Got to Now: Six Innovations That Made the Modern World

by Steven Johnson

  The physicist Richard Feynman once described the relationship between aesthetics and science in a similar vein:

  I have a friend who’s an artist and has sometimes taken a view which I don’t agree with very well. He’ll hold up a flower and say “Look how beautiful it is,” and I’ll agree. Then he says “I as an artist can see how beautiful this is but you as a scientist take this all apart and it becomes a dull thing,” and I think that he’s kind of nutty. First of all, the beauty that he sees is available to other people and to me too, I believe. Although I may not be quite as refined aesthetically as he is … I can appreciate the beauty of a flower. At the same time, I see much more about the flower than he sees. I could imagine the cells in there, the complicated actions inside, which also have a beauty. I mean it’s not just beauty at this dimension, at one centimeter; there’s also beauty at smaller dimensions, the inner structure, also the processes. The fact that the colors in the flower evolved in order to attract insects to pollinate it is interesting; it means that insects can see the color. It adds a question: does this aesthetic sense also exist in the lower forms? Why is it aesthetic? All kinds of interesting questions which shows that a science knowledge only adds to the excitement, the mystery and the awe of a flower. It only adds. I don’t understand how it subtracts.

  There is something undeniably appealing about the story of a great inventor or scientist—Galileo and his telescope, for instance—working his or her way toward a transformative idea. But there is another, deeper story that can be told as well: how the ability to make lenses also depended on the unique quantum mechanical properties of silicon dioxide and on the fall of Constantinople. Telling the story from that long-zoom perspective doesn’t subtract from the traditional account focused on Galileo’s genius. It only adds.

  Marin County, California

  February 2014

  1. Glass

  Roughly 26 million years ago, something happened over the sands of the Libyan Desert, the bleak, impossibly dry landscape that marks the eastern edge of the Sahara. We don’t know exactly what it was, but we do know that it was hot. Grains of silica melted and fused under an intense heat that must have been at least a thousand degrees. The compounds of silicon dioxide they formed have a number of curious chemical traits. Like H2O, they form crystals in their solid state, and melt into a liquid when heated. But silicon dioxide has a much higher melting point than water; you need temperatures above 500 degrees Fahrenheit instead of 32. But the truly peculiar thing about silicon dioxide is what happens when it cools. Liquid water will happily re-form the crystals of ice if the temperature drops back down again. But silicon dioxide for some reason is incapable of rearranging itself back into the orderly structure of crystal. Instead, it forms a new substance that exists in a strange limbo between solid and liquid, a substance human beings have been obsessed with since the dawn of civilization. When those superheated grains of sand cooled down below their melting point, a vast stretch of the Libyan Desert was coated with a layer of what we now call glass.

  About ten thousand years ago, give or take a few millennia, someone traveling through the desert stumbled across a large fragment of this glass. We don’t know anything more about that fragment, only that it must have impressed just about everyone who came into contact with it, because it circulated through the markets and social networks of early civilization, until it ended up as a centerpiece of a brooch, carved into the shape of a scarab beetle. It sat there undisturbed for four thousand years, until archeologists unearthed it in 1922 while exploring the tomb of an Egyptian ruler. Against all odds, that small sliver of silicon dioxide had found its way from the Libyan Desert into the burial chamber of Tutankhamun.

  Glass first made the transition from ornament to advanced technology during the height of the Roman Empire, when glassmakers figured out ways to make the material sturdier and less cloudy than naturally forming glass like that of King Tut’s scarab. Glass windows were built during this period for the first time, laying the groundwork for the shimmering glass towers that now populate city skylines around the world. The visual aesthetics of drinking wine emerged as people consumed it in semitransparent glass vessels and stored it in glass bottles. But, in a way, the early history of glass is relatively predictable: craftsmen figured out how to melt the silica into drinking vessels or windowpanes, exactly the sort of typical uses we instinctively associate with glass today. It wasn’t until the next millennium, and the fall of another great empire, that glass became what it is today: one of the most versatile and transformative materials in all of human culture.

  Pectoral in gold cloissoné with semiprecious stones and glass paste, with winged scarab, symbol of resurrection, in center, from the tomb of Pharaoh Tutankhamun

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  THE SACKING of Constantinople in 1204 was one of those historical quakes that send tremors of influence rippling across the globe. Dynasties fall, armies surge and retreat, the map of the world is redrawn. But the fall of Constantinople also triggered a seemingly minor event, lost in the midst of that vast reorganization of religious and geopolitical dominance and ignored by most historians of the time. A small community of glassmakers from Turkey sailed westward across the Mediterranean and settled in Venice, where they began practicing their trade in the prosperous new city growing out of the marshes on the shores of the Adriatic Sea.

  Circa 1900: Roman civilization, first–second century AD glass containers for ointments

  It was one of a thousand migrations set in motion by Constantinople’s fall, but looking back over the centuries, it turned out to be one of the most significant. As they settled into the canals and crooked streets of Venice, at that point arguably the most important hub of commercial trade in the world, their skills at blowing glass quickly created a new luxury good for the merchants of the city to sell around the globe. But lucrative as it was, glassmaking was not without its liabilities. The melting point of silicon dioxide required furnaces burning at temperatures near 1,000 degrees, and Venice was a city built almost entirely out of wooden structures. (The classic stone Venetian palaces would not be built for another few centuries.) The glassmakers had brought a new source of wealth to Venice, but they had also brought the less appealing habit of burning down the neighborhood.

  In 1291, in an effort to both retain the skills of the glassmakers and protect public safety, the city government sent the glassmakers into exile once again, only this time their journey was a short one—a mile across the Venetian Lagoon to the island of Murano. Unwittingly, the Venetian doges had created an innovation hub: by concentrating the glassmakers on a single island the size of a small city neighborhood, they triggered a surge of creativity, giving birth to an environment that possessed what economists call “information spillover.” The density of Murano meant that new ideas were quick to flow through the entire population. The glassmakers were in part competitors, but their family lineages were heavily intertwined. There were individual masters in the group that had more talent or expertise than the others, but in general the genius of Murano was a collective affair: something created by sharing as much as by competitive pressures.

  A section of a fifteenth-century map of Venice, showing the island of Murano

  By the first years of the next century, Murano had become known as the Isle of Glass, and its ornate vases and other exquisite glassware became status symbols throughout Western Europe. (The glassmakers continue to work their trade today, many of them direct descendants of the original families that emigrated from Turkey.) It was not exactly a model that could be directly replicated in modern times: mayors looking to bring the creative class to their cities probably shouldn’t consider forced exile and borders armed with the death penalty. But somehow it worked. After years of trial and error, experimenting with different chemical compositions, the Murano glassmaker Angelo Barovier took seaweed rich in potassium oxide and manganese, burned it to create ash, and then added these ingredients to molten glass. When the mixture cooled, it created an extr
aordinarily clear type of glass. Struck by its resemblance to the clearest rock crystals of quartz, Barovier called it cristallo. This was the birth of modern glass.

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  WHILE GLASSMAKERS such as Barovier were brilliant at making glass transparent, we didn’t understand scientifically why glass is transparent until the twentieth century. Most materials absorb the energy of light. On a subatomic level, electrons orbiting the atoms that made up the material effectively “swallow” the energy of the incoming photon of light, causing those electrons to gain energy. But electrons can gain or lose energy only in discrete steps, known as “quanta.” But the size of the steps varies from material to material. Silicon dioxide happens to have very large steps, which means that the energy from a single photon of light is not sufficient to bump up the electrons to the higher level of energy. Instead, the light passes through the material. (Most ultraviolet light, however, does have enough energy to be absorbed, which is why you can’t get a suntan through a glass window.) But light doesn’t simply pass through glass; it can also be bent and distorted or even broken up into its component wavelengths. Glass could be used to change the look of the world, by bending light in precise ways. This turned out to be even more revolutionary than simple transparency.

  In the monasteries of the twelfth and thirteenth centuries, monks laboring over religious manuscripts in candlelit rooms used curved chunks of glass as a reading aid. They would run what were effectively bulky magnifiers over the page, enlarging the Latin inscriptions. No one is sure exactly when or where it happened, but somewhere around this time in Northern Italy, glassmakers came up with an innovation that would change the way we see the world, or at least clarify it: shaping glass into small disks that bulge in the center, placing each one in a frame, and joining the frames together at the top, creating the world’s first spectacles.

  Those early spectacles were called roidi da ogli, meaning “disks for the eyes.” Thanks to their resemblance to lentil beans—lentes in Latin—the disks themselves came to be called “lenses.” For several generations, these ingenious new devices were almost exclusively the province of monastic scholars. The condition of “hyperopia”—farsightedness—was widely distributed through the population, but most people didn’t notice that they suffered from it, because they didn’t read. For a monk, straining to translate Lucretius by the flickering light of a candle, the need for spectacles was all too apparent. But the general population—the vast majority of them illiterate—had almost no occasion to discern tiny shapes like letterforms as part of their daily routine. People were farsighted; they just didn’t have any real reason to notice that they were farsighted. And so spectacles remained rare and expensive objects.

  The earliest image of a monk with glasses, 1342

  What changed all of that, of course, was Gutenberg’s invention of the printing press in the 1440s. You could fill a small library with the amount of historical scholarship that has been published documenting the impact of the printing press, the creation of what Marshall McLuhan famously called “the Gutenberg galaxy.” Literacy rates rose dramatically; subversive scientific and religious theories routed around the official channels of orthodox belief; popular amusements like the novel and printed pornography became commonplace. But Gutenberg’s great breakthrough had another, less celebrated effect: it made a massive number of people aware for the first time that they were farsighted. And that revelation created a surge in demand for spectacles.

  What followed was one of the most extraordinary cases of the hummingbird effect in modern history. Gutenberg made printed books relatively cheap and portable, which triggered a rise in literacy, which exposed a flaw in the visual acuity of a sizable part of the population, which then created a new market for the manufacture of spectacles. Within a hundred years of Gutenberg’s invention, thousands of spectacle makers around Europe were thriving, and glasses became the first piece of advanced technology—since the invention of clothing in Neolithic times—that ordinary people would regularly wear on their bodies.

  But the coevolutionary dance did not stop there. Just as the nectar of flowering plants encouraged a new kind of flight in the hummingbird, the economic incentive created by the surging market for spectacles engendered a new pool of expertise. Europe was not just awash in lenses, but also in ideas about lenses. Thanks to the printing press, the Continent was suddenly populated by people who were experts at manipulating light through slightly convex pieces of glass. These were the hackers of the first optical revolution. Their experiments would inaugurate a whole new chapter in the history of vision.

  Fifteenth-century glasses

  In 1590 in the small town of Middleburg in the Netherlands, father and son spectacle makers Hans and Zacharias Janssen experimented with lining up two lenses, not side by side like spectacles, but in line with each other, magnifying the objects they observed, thereby inventing the microscope. Within seventy years, the British scientist Robert Hooke had published his groundbreaking illustrated volume Micrographia, with gorgeous hand-drawn images re-creating what Hooke had seen through his microscope. Hooke analyzed fleas, wood, leaves, even his own frozen urine. But his most influential discovery came by carving off a thin sheaf of cork and viewing it through the microscope lens. “I could exceeding plainly perceive it to be all perforated and porous, much like a Honey-comb,” Hooke wrote, “but that the pores of it were not regular; yet it was not unlike a Honey-comb in these particulars … these pores, or cells, were not very deep, but consisted of a great many little Boxes.” With that sentence, Hooke gave a name to one of life’s fundamental building blocks—the cell—leading the way to a revolution in science and medicine. Before long the microscope would reveal the invisible colonies of bacteria and viruses that both sustain and threaten human life, which in turn led to modern vaccines and antibiotics.

  The Flea (engraving from Robert Hooke’s Micrographia, London)

  The microscope took nearly three generations to produce truly transformative science, but for some reason the telescope generated its revolutions more quickly. Twenty years after the invention of the microscope, a cluster of Dutch lensmakers, including Zacharias Janssen, more or less simultaneously invented the telescope. (Legend has it that one of them, Hans Lippershey, stumbled upon the idea while watching his children playing with his lenses.) Lippershey was the first to apply for a patent, describing a device “for seeing things far away as if they were nearby.” Within a year, Galileo got word of this miraculous new device, and modified the Lippershey design to reach a magnification of ten times normal vision. In January of 1610, just two years after Lippershey had filed for his patent, Galileo used the telescope to observe that moons were orbiting Jupiter, the first real challenge to the Aristotelian paradigm that assumed all heavenly bodies circled the Earth.

  This is the strange parallel history of Gutenberg’s invention. It has long been associated with the scientific revolution, for several reasons. Pamphlets and treatises from alleged heretics like Galileo could circulate ideas outside the censorious limits of the Church, ultimately undermining its authority; at the same time, the system of citation and reference that evolved in the decades after Gutenberg’s Bible became an essential tool in applying the scientific method. But Gutenberg’s creation advanced the march of science in another, less familiar way: it expanded possibilities of lens design, of glass itself. For the first time, the peculiar physical properties of silicon dioxide were not just being harnessed to let us see things that we could already see with our own eyes; we could now see things that transcended the natural limits of human vision.

  The lens would go on to play a pivotal role in nineteenth-and twentieth-century media. It was first utilized by photographers to focus beams of light on specially treated paper that captured images, then by filmmakers to both record and subsequently project moving images for the first time. Starting in the 1940s, we began coating glass with phosphor and firing electrons at it, creating the hypnotic images of television. Within a few years, s
ociologists and media theorists were declaring that we had become a “society of the image,” the literate Gutenberg galaxy giving way to the blue glow of the TV screen and the Hollywood glamour shot. Those transformations emerged out of a wide range of innovations and materials, but all of them, in one way or another, depended on the unique ability of glass to transmit and manipulate light.

  An early microscope designed by Robert Hooke, 1665

  To be sure, the story of the modern lens and its impact on media is not terribly surprising. There’s an intuitive line that you can follow from the lenses of the first spectacles, to the lens of a microscope, to the lens of a camera. Yet glass would turn out to have another bizarre physical property, one that even the master glassblowers of Murano had failed to exploit.

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  AS PROFESSORS GO, the physicist Charles Vernon Boys was apparently a lousy one. H. G. Wells, who was briefly one of Boys’s students at London’s Royal College of Science, later described him as “one of the worst teachers who has ever turned his back on a restive audience… . [He] messed about with the blackboard, galloped through an hour of talk, and bolted back to the apparatus in his private room.”