Where Good Ideas Come From Part 3

It's tempting to a.s.sume that the machinery of cultural innovation is closer to that engineer tinkering with her model airplane than it is to the lucky Archaeopteryx Archaeopteryx leaping off the treetop and discovering that its feathers are more than just a down jacket. No one contests the role of intelligent design in the history of human culture. But the history of human creativity abounds with exaptations. In the early 1800s, a French weaver named Joseph-Marie Jacquard developed the first punch cards to weave complex silk patterns with mechanical looms. Several decades later, Charles Babbage borrowed Jacquard's invention to program the a.n.a.lytical Engine. Punch cards would remain crucial to programmable computers until the 1970s. Lee de Forest created the Audion with one clear aim: to create a device that would detect electromagnetic signals and amplify them. It never occurred to him that the triode architecture could just as easily be applied to the problem of building a hydrogen bomb. In evolutionary terms, the vacuum tube was originally adapted to make signals louder, but it was eventually exapted to turn those signals into information: zeros and ones that could be manipulated in astonis.h.i.+ng ways. A Fender guitar amp from the fifties that relied on a vacuum tube to boost the signal of the first rock-and-roll guitarists was, ultimately, a variation on de Forest's original amplification theme. But those 17,000 vacuum tubes inside ENIAC, doing the math on the physics of a hydrogen bomb-they were serving a function that never crossed de Forest's mind, however imaginative it might have been. Today, emerging patent marketplaces like Nike's GreenXchange are enabling commercial exaptations that would have been unthinkable in the fortified environment of traditional R&D labs. leaping off the treetop and discovering that its feathers are more than just a down jacket. No one contests the role of intelligent design in the history of human culture. But the history of human creativity abounds with exaptations. In the early 1800s, a French weaver named Joseph-Marie Jacquard developed the first punch cards to weave complex silk patterns with mechanical looms. Several decades later, Charles Babbage borrowed Jacquard's invention to program the a.n.a.lytical Engine. Punch cards would remain crucial to programmable computers until the 1970s. Lee de Forest created the Audion with one clear aim: to create a device that would detect electromagnetic signals and amplify them. It never occurred to him that the triode architecture could just as easily be applied to the problem of building a hydrogen bomb. In evolutionary terms, the vacuum tube was originally adapted to make signals louder, but it was eventually exapted to turn those signals into information: zeros and ones that could be manipulated in astonis.h.i.+ng ways. A Fender guitar amp from the fifties that relied on a vacuum tube to boost the signal of the first rock-and-roll guitarists was, ultimately, a variation on de Forest's original amplification theme. But those 17,000 vacuum tubes inside ENIAC, doing the math on the physics of a hydrogen bomb-they were serving a function that never crossed de Forest's mind, however imaginative it might have been. Today, emerging patent marketplaces like Nike's GreenXchange are enabling commercial exaptations that would have been unthinkable in the fortified environment of traditional R&D labs.

The history of the World Wide Web is, in a sense, a story of continuous exaptation. Tim Berners-Lee designs the original protocols with a specifically academic environment in mind, creating a platform for sharing research in a hypertext format. But when the first Web pages crawl out of that scholarly primordial soup and begin to engage with ordinary consumers, Berners-Lee's invention turns out to possess a remarkable number of unantic.i.p.ated qualities. A platform adapted for scholars.h.i.+p was exapted for shopping, and sharing photos, and watching p.o.r.nography-along with a thousand other uses that would have astounded Berners-Lee when he created his first HTML-based directories in the early nineties. When Sergey Brin and Larry Page decided to use links between Web pages as digital votes endorsing the content of those pages, they were exapting Berners-Lee's original design: they took a trait adapted for navigation-the hypertext link-and used it as a vehicle for a.s.sessing quality. The result was PageRank, the original algorithm that made Google into the behemoth that it is today.

The literary historian Franco Moretti has persuasively doc.u.mented the role of exaptation in the evolution of the novel. An author conceives a new kind of narrative device to address a specific, local need in a work he or she is writing. Something about the device resonates with other authors, and it begins to circulate through the literary gene pool. And then, as the literary environment changes and new imaginative possibilities become necessary, the device turns out to have a different function, far removed from its original use. The French novelist Edouard Dujardin first uses the "stream of consciousness" technique in his 1888 novel Les Lauriers sont coupes Les Lauriers sont coupes; in Dujardin's rendition, the technique is restricted to short periods of introspection between the main events of the story, brief parentheses within the plot. But three decades later, James Joyce would take the device and transform it into the most memorable and mesmerizing perceptual modes, using the device in his novel Ulysses Ulysses to capture the churn and distractibility of mental life in a bustling city. When d.i.c.kens conjured up his Inspector Bucket to weave together the multiplying strands of metropolitan coincidence in to capture the churn and distractibility of mental life in a bustling city. When d.i.c.kens conjured up his Inspector Bucket to weave together the multiplying strands of metropolitan coincidence in Bleak House Bleak House, he had no idea his contrivance would help create a whole new genre of detective fiction, one that would extend all the way from Wilkie Collins's The Moonstone The Moonstone to Sherlock Holmes to to Sherlock Holmes to Murder, She Wrote Murder, She Wrote. New genres need old devices.

Rhetorical or figurative exaptations are not the exclusive property of the arts. The history of scientific and technological innovation abounds with them as well. In The Act of Creation The Act of Creation, Arthur Koestler argued that "all decisive events in the history of scientific thought can be described in terms of mental cross-fertilization between different disciplines." Concepts from one domain migrate to another as a kind of structuring metaphor, thereby unlocking some secret door that had long been hidden from view. In his memoirs, Francis Crick reports that he first hit upon the complementary replication system of DNA-each base A matched with a T, and each C with a G-by thinking of the way a work of sculpture can be reproduced by making an impression in plaster, and then using that impression, when dry, as a mold to create copies. Johannes Kepler credited his laws of planetary motion to a generative metaphor imported from religion; he imagined the sun, stars, and the dark s.p.a.ce between them as the celestial equivalents of the Father, Son, and Holy Ghost. When computer science pioneers like Doug Engelbart and Alan Kay invented the graphical interface, they imported a metaphor from the real-world environment of offices: instead of organizing information on the screen as a series of command-line inputs, the way a programmer would, they borrowed the iconography of a desktop with pieces of paper stacked on it. Kekule didn't think the benzene molecule was literally a snake from Greek mythology, but his knowledge of that ancient symbol helped him solve one of the essential problems of organic chemistry.

In the early 1970s, a Berkeley sociologist named Claude Fischer began investigating the social effects of living in dense urban centers. The topic was one that had long interested urban theorists, most famously in Louis Wirth's cla.s.sic essay from 1938, "Urbanism as a Way of Life," which argued that metropolitan living led toward social disorganization and alienation, the social ties and comforts of smaller communities breaking down in the tumult of the big city. Wirth's argument had not aged well-it turned out that densely populated neighborhoods had very complex and rich social bonds if one looked for them-and so Fischer set out to determine what social patterns were truly precipitated by the environment of large cities. His research led him to one overwhelming conclusion, published in a seminal paper in 1975: big cities nurture subcultures subcultures much more effectively than suburbs or small towns. much more effectively than suburbs or small towns.

Lifestyles or interests that deviate from the mainstream need critical ma.s.s to survive; they atrophy in smaller communities not because those communities are more repressive, but rather because the odds of finding like-minded people are much lower with a smaller pool of individuals. If one-tenth of one percent of the population are pa.s.sionately interested in, say, beetle collecting or improv theater, there might only be a dozen such individuals in a midsized town. But in a big city there might be thousands. As Fischer noted, that cl.u.s.tering creates a positive feedback loop, as the more unconventional residents of the suburbs or rural areas migrate to the city in search of fellow travelers. "The theory . . . explains the 'evil' and 'good' of cities simultaneously," Fischer wrote. "Criminal unconventionality and innovative (e.g., artistic) unconventionality are both nourished by vibrant subcultures." Poetry collectives and street gangs might seem miles apart on the surface, but they each depend on the city's capacity for nurturing subcultures.

The same pattern holds true for trades and businesses in large cities. As Jane Jacobs observed in The Death and Life of Great American Cities The Death and Life of Great American Cities: "The larger a city, the greater the variety of its manufacturing, and also the greater both the number and the proportion of its small manufacturers."

Towns and suburbs, for instance, are natural homes for huge supermarkets and for little else in the way of groceries, for standard movie houses or drive-ins and for little else in the way of theater. There are simply not enough people to support further variety, although there may be people (too few of them) who would draw upon it were it there. Cities, however, are the natural homes of supermarkets and standard movie houses plus delicatessens, Viennese bakeries, foreign groceries, art movies, and so on, all of which can be found co-existing, the standard with the strange, the large with the small. Wherever lively and popular parts of cities are found, the small much outnumber the large.

Both Fischer and Jacobs emphasize the fertile interactions that occur between subcultures in a dense city center, the inevitable spillover that happens whenever human beings crowd together in large groups. Subcultures and eclectic businesses generate ideas, interests, and skills that inevitably diffuse through the society, influencing other groups. As Fischer puts it, "The larger the town, the more likely it is to contain, in meaningful numbers and unity, drug addicts, radicals, intellectuals, 'swingers,' health-food faddists, or whatever; and the more likely they are to influence (as well as offend) the conventional center of the society."

Cities, then, are environments that are ripe for exaptation, because they cultivate specialized skills and interests, and they create a liquid network where information can leak out of those subcultures, and influence their neighbors in surprising ways. This is one explanation for superlinear scaling in urban creativity. The cultural diversity those subcultures create is valuable not just because it makes urban life less boring. The value also lies in the unlikely migrations that happen between the different cl.u.s.ters. A world where a diverse mix of distinct professions and pa.s.sions overlap is a world where exaptations thrive.

Those shared environments often take the form of a real-world public s.p.a.ce, what the sociologist Ray Oldenburg famously called the "third place," a connective environment distinct from the more insular world of home or office. The eighteenth-century English coffeehouse fertilized countless Enlightenment-era innovations; everything from the science of electricity, to the insurance industry, to democracy itself. Freud maintained a celebrated salon Wednesday nights at 19 Bergga.s.se in Vienna, where physicians, philosophers, and scientists gathered to help shape the emerging field of psychoa.n.a.lysis. Think, too, of the Paris cafes where so much of modernism was born; or the legendary Homebrew Computer Club in the 1970s, where a ragtag a.s.semblage of amateur hobbyists, teenagers, digital entrepreneurs, and academic scientists managed to spark the personal computer revolution. Partic.i.p.ants flock to these s.p.a.ces partly for the camaraderie of others who share their pa.s.sions, and no doubt that support network increases the engagement and productivity of the group. But encouragement does not necessarily lead to creativity. Collisions Collisions do-the collisions that happen when different fields of expertise converge in some shared physical or intellectual s.p.a.ce. That's where the true sparks fly. The modernism of the 1920s exhibited so much cultural innovation in such a short period of time because the writers, poets, artists, and architects were all rubbing shoulders at the same cafes. They weren't off on separate islands, teaching creative writing seminars or doing design reviews. That physical proximity made the s.p.a.ce rich with exaptation: the literary stream of consciousness influencing the dizzying new perspectives of cubism; the futurist embrace of technological speed in poetry shaping new patterns of urban planning. do-the collisions that happen when different fields of expertise converge in some shared physical or intellectual s.p.a.ce. That's where the true sparks fly. The modernism of the 1920s exhibited so much cultural innovation in such a short period of time because the writers, poets, artists, and architects were all rubbing shoulders at the same cafes. They weren't off on separate islands, teaching creative writing seminars or doing design reviews. That physical proximity made the s.p.a.ce rich with exaptation: the literary stream of consciousness influencing the dizzying new perspectives of cubism; the futurist embrace of technological speed in poetry shaping new patterns of urban planning.

Exaptation also prospers on another scale: the shared media media environment of a physical community. In the late 1970s, the British musician and artist Brian Eno moved to New York City for the first time. He took over a flat in a converted town house in the heart of the Village. The city was at the height-or more like the nadir-of its rioting, Son of Sam-fearing, bankruptcy-flirting madness. Still, having spent time in 1970s London and Berlin, Eno was well acclimated to urban anarchy. In fact, the most jarring contrast to his European past was the turbulent mix of voices on the radio. After years of listening to the somber, professional voices of the BBC, the outlandish rants of American radio seemed to Eno like a new universe of insanity. environment of a physical community. In the late 1970s, the British musician and artist Brian Eno moved to New York City for the first time. He took over a flat in a converted town house in the heart of the Village. The city was at the height-or more like the nadir-of its rioting, Son of Sam-fearing, bankruptcy-flirting madness. Still, having spent time in 1970s London and Berlin, Eno was well acclimated to urban anarchy. In fact, the most jarring contrast to his European past was the turbulent mix of voices on the radio. After years of listening to the somber, professional voices of the BBC, the outlandish rants of American radio seemed to Eno like a new universe of insanity.

And so he started taping them. Like many experimental musicians at that point, Eno had been exploring the possibilities of using tape loops as a musical instrument. ("The tape recorder was always the instrument I felt most comfortable with," he once said in an interview. "Keyboards after that, with ba.s.s as a distant third.") The Beatles had reserved the longest track on the White Alb.u.m for Lennon's tape-loop collage "Revolution #9," and the proto-synthesizer Mellotron, developed in the mid-sixties, had separate tape loops set up to be triggered by individual keys on the keyboard. But none of those experiments had ever really employed the spoken voice as a harmonic or percussive element. The drones and murmurs of "Revolution #9" were, after all, barely musical by traditional standards. But Eno's hours with the evangelists and the anarchists and the shock-jocks-in-embryo had lodged those voices in his head, and as he began work on a collaboration with David Byrne, he started to toy with the idea of exploring their musical possibilities. The result was My Life in the Bush of Ghosts My Life in the Bush of Ghosts, an utterly original mix of African rhythm sections and oddball acoustic instruments, but notably missing Byrne's taut New Wave vocal stylings-so prominently featured in the Talking Heads alb.u.ms the two had previously collaborated on. Instead of traditional singing, Byrne and Eno built the songs around the layered, looped ensemble of spoken words that Eno had grabbed from the airwaves. It was a case study in creative exaptation: words designed in one medium to spread the word of Jesus, or to thunder against the military-industrial complex, migrated over into a new environment and became, against all odds, music.

My Life in the Bush of Ghosts marked the birth of a certain historically crucial kind of musical borrowing: it was not just a new music, but a whole new way of thinking about what music could be built out of. (Not unlike the way Marcel Duchamp and his fellow surrealists had changed our understanding of what art could be made of fifty years before.) Several years later, when Public Enemy producer Hank Shocklee sat down to record the alb.u.m marked the birth of a certain historically crucial kind of musical borrowing: it was not just a new music, but a whole new way of thinking about what music could be built out of. (Not unlike the way Marcel Duchamp and his fellow surrealists had changed our understanding of what art could be made of fifty years before.) Several years later, when Public Enemy producer Hank Shocklee sat down to record the alb.u.m It Takes a Nation of Millions to Hold Us Back It Takes a Nation of Millions to Hold Us Back, he deliberately mimicked the layered, percussive vocal samples of Eno and Byrne's production. It Takes a Nation It Takes a Nation went on to become one of the most sonically influential records of its decade, reverberating through the wider culture-in everything from cell phone jingles to billboard chart-toppers to avant-garde experimentation-just as went on to become one of the most sonically influential records of its decade, reverberating through the wider culture-in everything from cell phone jingles to billboard chart-toppers to avant-garde experimentation-just as Highway 61 Revisited Highway 61 Revisited and and Pet Sounds Pet Sounds had done a generation before. Eno's original innovation was brilliant, to be sure, and from a distance it almost looks like the cla.s.sic "lone genius" eureka moment: the innovator locked away in his lab, stumbling across an idea that would transform the wider culture. But it is crucial to the story that Eno was not, technically speaking, alone with his tape recorder: he was tapped into a network of wildly different voices, all of them ranting at different frequencies. Eno didn't need a coffeehouse. He had AM radio. had done a generation before. Eno's original innovation was brilliant, to be sure, and from a distance it almost looks like the cla.s.sic "lone genius" eureka moment: the innovator locked away in his lab, stumbling across an idea that would transform the wider culture. But it is crucial to the story that Eno was not, technically speaking, alone with his tape recorder: he was tapped into a network of wildly different voices, all of them ranting at different frequencies. Eno didn't need a coffeehouse. He had AM radio.

In the late nineties, a Stanford Business School professor named Martin Ruef decided to investigate the relations.h.i.+p between business innovation and diversity. Ruef was interested in the coffeehouse model of diversity, not the "melting pot" political kind: the diversity of professions and disciplines, not of race or s.e.xual orientation. Ruef interviewed 766 graduates of the school who had gone on to have entrepreneurial careers. He created an elaborate system for scoring innovation based on a combination of factors: the introduction of new products, say, or the filing of trademarks and patents. And then he tracked each graduate's social network-not just the number of acquaintances but the kind kind of acquaintances they had. Some graduates had large social networks that were cl.u.s.tered within their organization; others had small insular groups dominated by friends and family. Some had wide-ranging connections with acquaintances outside their inner circle of friends and colleagues. of acquaintances they had. Some graduates had large social networks that were cl.u.s.tered within their organization; others had small insular groups dominated by friends and family. Some had wide-ranging connections with acquaintances outside their inner circle of friends and colleagues.

What Ruef discovered was a ringing endors.e.m.e.nt of the coffeehouse model of social networking: the most creative individuals in Ruef's survey consistently had broad social networks that extended outside their organization and involved people from diverse fields of expertise. Diverse, horizontal social networks, in Ruef's a.n.a.lysis, were three times three times more innovative than uniform, vertical networks. In groups united by shared values and long-term familiarity, conformity and convention tended to dampen any potential creative sparks. The limited reach of the network meant that interesting concepts from the outside rarely entered the entrepreneur's consciousness. But the entrepreneurs who built bridges outside their "islands," as Ruef called them, were able to borrow or co-opt new ideas from these external environments and put them to use in a new context. A similar study, conducted by a University of Chicago business school professor named Ronald Burt, looked at the origin of good ideas inside the organizational network of the Raytheon Corporation. Burt found that innovative thinking was much more likely to emerge from individuals who bridged "structural holes" between tightly knit cl.u.s.ters. Employees who primarily shared information with people in their own division had a harder time coming up with useful suggestions for Raytheon's business, when measured against employees who maintained active links to a more diverse group. more innovative than uniform, vertical networks. In groups united by shared values and long-term familiarity, conformity and convention tended to dampen any potential creative sparks. The limited reach of the network meant that interesting concepts from the outside rarely entered the entrepreneur's consciousness. But the entrepreneurs who built bridges outside their "islands," as Ruef called them, were able to borrow or co-opt new ideas from these external environments and put them to use in a new context. A similar study, conducted by a University of Chicago business school professor named Ronald Burt, looked at the origin of good ideas inside the organizational network of the Raytheon Corporation. Burt found that innovative thinking was much more likely to emerge from individuals who bridged "structural holes" between tightly knit cl.u.s.ters. Employees who primarily shared information with people in their own division had a harder time coming up with useful suggestions for Raytheon's business, when measured against employees who maintained active links to a more diverse group.

To a certain extent, Ruef's and Burt's research is a validation of the celebrated "strength of weak ties" argument first proposed by Mark Granovetter, and popularized by Malcolm Gladwell in The Tipping Point The Tipping Point. But looking at the weak ties of an extended social network through the lens of exaptation changes the picture in an important way: it is not merely that weak ties allow information to travel throughout a network more efficiently-that is, without becoming trapped on the remote island of a close-knit group. From the perspective of innovation, it's even more important that the information arriving from one of those weak ties is coming from a different context, what the innovation scholar Richard Ogle calls an "idea-s.p.a.ce": a complex of tools, beliefs, metaphors, and objects of study. A new technology developed in one idea-s.p.a.ce can migrate over to another idea-s.p.a.ce through these long-distance connections; in that new environment, the technology may turn out to have unantic.i.p.ated properties, or may trigger a connection that leads to a new breakthrough. The value of the weak tie lies not just in the speed with which it transmits information across a network; it also promotes the exaptation of those ideas. Gutenberg was trained as a metallurgist, but he had weak ties to the vintners of Rhineland Germany. Without that link, he would have been merely a pioneering typesetter, making an incremental improvement on Pi Sheng's movable type. By not restricting himself exclusively to the island of metallurgy, he became something much more important: a printer.

The model of weak-tie exaptation also helps us understand the cla.s.sic story of twentieth-century scientific epiphany: Watson and Crick's discovery of the double-helix structure of DNA. As Ogle and others have noted, in the small scientific community working on the problem of DNA in the early 1950s, the person who had the clearest and most direct view of the molecule itself was neither James Watson nor Francis Crick. It was, instead, a biophysicist at London University named Rosalind Franklin, who was using state-of-the-art X-ray crystallography to study the mysterious strands of DNA. But Franklin's vision was limited by two factors. First, there was the imperfect state of the X-ray technology, which only gave her hints about the helix structure and base-pair symmetry. But Franklin was also limited by the conceptual island on which she based her work. Her approach was purely inductive: master the X-ray technology and then use the information collected to build a model of DNA. ("We're going to let the data tell us the structure," she famously told Crick.) But to "see" the double-helix in the early 1950s took something more than just a.n.a.lyzing it in an X-ray machine. To solve the mystery, Watson and Crick had to piece it together with tools drawn from multiple disciplines: biochemistry, genetics, information theory, and mathematics, not to mention Franklin's X-ray images. Even Crick's sculpture metaphor proved crucial to cracking the code. Next to Franklin, Watson and Crick seemed almost dilettantes and dabblers: Crick had switched from physics to biology in his graduate years; neither had a comprehensive grasp of biochemistry. But DNA was not a problem that could be solved within a single discipline. Watson and Crick had to borrow from other domains to make sense of the molecule. As Ogle puts it, "Once key ideas from idea-s.p.a.ces that otherwise had little contact with one another were connected, they began, quasi-autonomously, to make new sense in terms of one another, leading to the emergence of a whole that was more than the sum of its parts." It is a fitting footnote to the story that Watson and Crick were notorious for taking long, rambling coffee breaks, where they tossed around ideas in a more playful setting outside the lab-a practice that was generally scorned by their more fastidious colleagues. With their weak-tie connections to disparate fields, and their exaptative intelligence, Watson and Crick worked their way to a n.o.bel Prize in their own private coffeehouse.

The coffeehouse model of creativity helps explain one of those strange paradoxes of twenty-first-century business innovation. Even as much of the high-tech culture has embraced decentralized, liquid networks in their approach to innovation, the company that is consistently ranked as the most innovative in the world-Apple-remains defiantly top-down and almost comically secretive in its development of new products. You won't ever see Steve Jobs or Jonathan Ive crowdsourcing development of the next-generation iPhone. If open and dense networks lead to more innovation, how can we explain Apple, which on the spectrum of openness is far closer to w.i.l.l.y Wonka's factory than it is to Wikipedia? The easy answer is that Jobs and Ive simply possess a collaborative genius that has enabled the company to s.h.i.+p such a reliable stream of revolutionary products. No doubt both men are immensely talented at what they do, but neither of them can design, build, program, and market a product as complex as the iPhone on their own, the way Jobs and Steve Wozniak crafted the original Apple personal computer in the now-legendary garage. Apple clearly has unparalleled leaders.h.i.+p, but there must also be something in the environment at Apple that is allowing such revolutionary ideas to make it to the marketplace.

As it turns out, while Apple has largely adopted a fortress mentality toward the outside world, the company's internal development process is explicitly structured to facilitate clash and connection between different perspectives. Jobs himself has taken to describing their method via the allegory of the concept car. You go to an auto show and see some glamorous and wildly innovative concept car on display and you think, "I'd buy that in a second." And then five years later, the car finally comes to market and it's been whittled down from a Ferrari to a Pinto-all the truly breakthrough features have been toned down or eliminated altogether, and what's left looks mostly like last year's model. The same sorry fate could have befallen the iPod as well: Ive and Jobs could have sketched out a brilliant, revolutionary music player and then two years later released a dud. What kept the spark alive?

The answer is that Apple's development cycle looks more like a coffeehouse than an a.s.sembly line. The traditional way to build a product like the iPod is to follow a linear chain of expertise. The designers come up with a basic look and feature set and then pa.s.s it on to the engineers, who figure out how to actually make it work. And then it gets pa.s.sed along to the manufacturing folks, who figure out how to build it in large numbers-after which it gets sent to the marketing and sales people, who figure out how to persuade people to buy it. This model is so ubiquitous because it performs well in situations where efficiency is key, but it tends to have disastrous effects on creativity, because the original idea gets chipped away at each step in the chain. The engineering team takes a look at the original design and says, "Well, we can't really do that-but we can do 80 percent of what you want." And then the manufacturing team says, "Sure, we can do some of that." In the end, the original design has been watered down beyond recognition.

Apple's approach, by contrast, is messier and more chaotic at the beginning, but it avoids this chronic problem of good ideas being hollowed out as they progress through the development chain. Apple calls it concurrent or parallel production. All the groups-design, manufacturing, engineering, sales-meet continuously through the product-development cycle, brainstorming, trading ideas and solutions, strategizing over the most pressing issues, and generally keeping the conversation open to a diverse group of perspectives. The process is noisy and involves far more open-ended and contentious meetings than traditional production cycles-and far more dialogue between people versed in different disciplines, with all the translation difficulties that creates. But the results speak for themselves.

Many of history's great innovators managed to build a cross-disciplinary coffeehouse environment within their own private work routines. It is an oft-told story that Darwin delayed publis.h.i.+ng his theory of evolution because he feared the controversy it would unleash, particularly after the death of his beloved daughter Annie traumatized his religious wife, Emma. But Darwin also had an immense number of side interests to distract him from his opus: he studied coral reefs, bred pigeons, performed elaborate taxonomical studies of beetles and barnacles, wrote important papers on the geology of South America, spent years researching the impact of earthworms on the soil. None of these pa.s.sions were central to the argument that would eventually be published as On the Origin of Species On the Origin of Species, but each contributed useful links of a.s.sociation and expertise to the problem of evolution. The same eclectic pattern appears in countless other biographies. Joseph Priestley bounced between chemistry, physics, theology, and political theory. Even in the years before he became a political statesman, Benjamin Franklin conducted electricity experiments, theorized the existence of the Gulf Stream, designed stoves, and of course made a small fortune as a printer. While John Snow was solving the mystery of cholera in the streets of London in the 1850s, he was also inventing state-of-the-art technology for the administration of ether, publis.h.i.+ng research on lead poisoning and the resuscitation of stillborn children, yet all the while tending to his patients as a general pract.i.tioner. Legendary innovators like Franklin, Snow, and Darwin all possess some common intellectual qualities-a certain quickness of mind, unbounded curiosity-but they also share one other defining attribute. They have a lot of hobbies.

The historian Howard Gruber likes to call such concurrent projects "networks of enterprise," but I prefer to describe them using a contemporary term that has been much maligned of late: mult.i.tasking. This is not, of course, the mult.i.tasking of the modern computer screen: switching from e-mail to spreadsheet to Twitter in a matter of seconds. What I'm describing is much more leisurely than that frenetic, digital-age mode; the individual tasks themselves might linger on for days or weeks before giving way to the next project. But there is steady variation nonetheless, not just in the subject matter but in the kind of work performed in each task. For John Snow, there were fundamentally different modes of intellectual activity involved in his many projects: building mechanical contraptions to control the temperature of chloroform required different skills and a different mind-set from tending to patients or writing papers for The Lancet The Lancet. It is tempting to call this mode of work "serial tasking," in the sense that the projects rotate one after the other, but emphasizing the serial nature of the work obscures one crucial aspect of this mental environment: in a slow mult.i.tasking mode, one project takes center stage for a series of hours or days, yet the other projects linger in the margins of consciousness throughout. That cognitive overlap is what makes this mode so innovative. The current project can exapt ideas from the projects at the margins, make new connections. It is not so much a question of thinking outside the box, as it is allowing the mind to move through multiple boxes. That movement from box to box forces the mind to approach intellectual roadblocks from new angles, or to borrow tools from one discipline to solve problems in another.

The standard story about Snow is that he solved the mystery of cholera's waterborne transmission by doing shoe-leather epidemiological detective work during the 1854 Soho outbreak, but the truth is he had built a convincing rendition of the waterborne theory well before 1854. One reason he was able to see around the biases of the reigning "miasma" theory of the day-which maintained that cholera was caused by the inhalation of noxious vapors-is that his work with anesthesia had given him a hands-on knowledge of the way that gases diffused through the atmosphere. Snow reasoned that a disease transmitted by poisonous gas would leave a distinct pattern in the geographic spread of mortality: ma.s.sive death in the immediate proximity of the bad smells, tapering off very quickly as one moved away from the original source. By the same token, Snow's training as a physician helped him shed the miasma blinders as well: from tending to patients ill with cholera, Snow observed that the effects of the disease on the human body indicated that the agent had been ingested, not inhaled, given that it did almost all of its direct damage in the digestive system and left the lungs largely unaffected. In a real sense, for Snow to make his great breakthrough in understanding cholera, he had to think like a molecular chemist and and like a physician. As a slow mult.i.tasker, he had those interpretative systems readily available to him when his focus turned to the mystery of cholera. As we saw with the feathers of like a physician. As a slow mult.i.tasker, he had those interpretative systems readily available to him when his focus turned to the mystery of cholera. As we saw with the feathers of Archaeopteryx Archaeopteryx, Snow couldn't have antic.i.p.ated that his mechanical tinkering with chloroform inhalers would prove useful in ridding the modern world of a deadly bacterium, but that is the unpredictable power of exaptations. Chance favors the connected mind.

VII.

PLATFORMS.

On April 12, 1836, HMS Beagle Beagle took leave of the Keeling Islands, after a two-week idyll that had given Darwin the crucial evidence he needed to support the first great idea of his young career. As the s.h.i.+p left the placid green waters of the lagoon, heading home to England via the island of Mauritius, Captain FitzRoy plumbed the depths on the periphery of the atoll with a line more than 7,000 feet long. He encountered no bottom. FitzRoy's measurements confirmed, in Darwin's words, that the "island forms a lofty submarine mountain, with sides steeper even than those of the most abrupt volcanic cone." The data was crucial to Darwin, because he was building a theory in his mind about "lofty submarine mountains" and their geological legacy. took leave of the Keeling Islands, after a two-week idyll that had given Darwin the crucial evidence he needed to support the first great idea of his young career. As the s.h.i.+p left the placid green waters of the lagoon, heading home to England via the island of Mauritius, Captain FitzRoy plumbed the depths on the periphery of the atoll with a line more than 7,000 feet long. He encountered no bottom. FitzRoy's measurements confirmed, in Darwin's words, that the "island forms a lofty submarine mountain, with sides steeper even than those of the most abrupt volcanic cone." The data was crucial to Darwin, because he was building a theory in his mind about "lofty submarine mountains" and their geological legacy.

The theory had emerged years before as a hunch: that his mentor Charles Lyell's theory of atoll formation had a critical flaw that revolved around the statistical likelihood that a mountain would just happen to settle only a few feet above sea level. The elevation variation in volcanic islands was immense: some tapered off a dozen feet above sea level; others, like Mauna Kea, surged ten thousand feet into the sky. Most volcanic peaks lay thousands of feet below the surface. Yet Darwin, like most geologists of his age, knew that the oceans were populated by a huge number of tropical atolls that had all somehow simultaneously landed within a few feet of sea level. It was like scattering a hundred footb.a.l.l.s across a field and having twenty of them cl.u.s.ter exactly on the forty-three-yard line. Darwin didn't have the theory of plate tectonics, but he knew that landma.s.ses were rising and descending around the world. But it made no sense that these epic forces were somehow being arrested, in a significant number of cases, by the dividing line of sea level. A volcano being pushed upward by immense planetary conveyor belts should, by all rights, quickly burst through the ocean's surface and continue climbing, as Mauna Kea and countless other island volcanoes did. By the same logic, a mountain sliding into the sea should keep sliding. Why were so many of these mountains getting stuck?

We don't know exactly when the answer came to Darwin. It may well have occurred to him standing on the white sands of a Keeling Islands beach. More likely, knowing Darwin, the idea rolled in slowly, inch by inch, and some small piece of it came to him standing in those green waters. The idea was simple, but strangely hard to visualize. It began with one defining principle: the ground beneath Darwin's feet was not the product of geological forces. An organism had engineered it.

That organism was Scleractinia, more commonly known as reef-building coral. Alive, an individual Scleractinia is a soft polyp, no more than a few millimeters long. Reef-building corals grow in vast colonies, with new polyps appearing as buds on the sides of their "parents." It is one of the strange ironies of marine biology that the coral's essential contribution to the undersea ecosystem takes place after its death. The polyp builds a calcium-based exoskeleton during its life, producing a mineral called aragonite, which is st.u.r.dy enough to remain intact centuries after its original host has perished. A coral reef, then, is a kind of vast underwater mausoleum: millions of skeletons united to form the pocked, labyrinthine sprawl of a reef.

During his fortnight on the Keeling Islands, Darwin had observed that the soil of the island was entirely devoid of traditional rocks. As he put it in his diary, "Throughout the whole group of Islands, every single atom, even from the most minute particle to large fragments of rocks, bear [sic] the stamp of once having been subjected to the power of organic arrangement." The vast majority of those particles and rocks were aragonite skeletons, the remains of a coral polyp that had died decades or centuries before. This alone was evidence that Lyell's theory was flawed: if Darwin was standing at the tip of a dormant undersea volcano, the rocks at his feet would have been basalt or obsidian or pumice, rocks created from the cooling of molten lava. The rocks would have been forged in a fiery core of magma, not excreted by minuscule polyps.

The fact that the soil of an Indian Ocean atoll was organic in nature, engineered by coral and not the product of volcanic activity, did not, on its own, offer a satisfactory answer to the mystery of the atoll's existence. Why should a colony of coral form such a perfect oval in the middle of an immense ocean, hundreds of miles from another landma.s.s? To solve that mystery, Darwin drew on Lyell's original theory, but he added an essential twist. He turned a still frame into a moving picture. To understand atoll formation, Darwin realized, you had to imagine a volcanic island slowly subsiding into the sea. As the banks of the volcano disappeared beneath the ocean waves, those slopes would become prime breeding ground for coral colonies, which thrive in shallow water at depths up to around 150 feet. (Their diet relies substantially on photosynthetic algae that cannot survive too far from the sunlit surface of the water.) Eventually the summit of the mountain slides into the sea, leaving a circle of shallow water defined by the periphery of the volcanic crater. Because the mountain is subsiding so slowly, the coral are able to build their reefs faster than the mountain can descend. Like overzealous developers, the coral colonies keep adding new floors to the structure they've erected at the top of the volcano, limited only by the water's surface. As the original peak descends further and further into the sea, the older reefs die off, but continue to give structural support to the new, thriving reefs above them. Darwin had no way of measuring this precisely, but he predicted that fossil coral would extend as far as five thousand feet below sea level before hitting a volcanic foundation, a number that was confirmed more than a century later with modern drilling technology.

As the Beagle Beagle departed, Darwin captured the miraculous nature of this explanation in his diary. "We must look at a Lagoon [island] as a monument raised by myriads of tiny architects," he wrote, "to mark the spot where a former land lies buried in the depths of the ocean." departed, Darwin captured the miraculous nature of this explanation in his diary. "We must look at a Lagoon [island] as a monument raised by myriads of tiny architects," he wrote, "to mark the spot where a former land lies buried in the depths of the ocean."

Published several years later as a monograph, Darwin's theory of atoll formation marked his first significant contribution to science, and it has largely stood the test of time. The idea itself drew on a coffeehouse of different disciplines: to solve the mystery, he had to think like a naturalist, a marine biologist, and a geologist all at once. He had to understand the life cycle of coral colonies, and observe the tiny evidence of organic sculpture on the rocks of the Keeling Islands; he had to think on the immense time scales of volcanic mountains rising and falling into the sea. And, of course, he needed FitzRoy's technical expertise with the sounding line. To understand the idea in its full complexity required a kind of probing intelligence, willing to think across those different disciplines and scales. Darwin described it best in the chapter on his Keeling Islands investigations from The Voyage of The Beagle The Voyage of The Beagle: "We feel surprise when travelers tell us of the vast dimensions of the Pyramids and other great ruins, but how utterly insignificant are the greatest of these, when compared to these mountains of stone acc.u.mulated by the agency of various minute and tender animals. This is a wonder which does not at first strike the eye of the body, but, after reflection, the eye of reason."

From Darwin's perspective, those "minute and tender animals" had built a platform, in the most prosaic sense of the word. Darwin was walking on that saucer-shaped summit, and not treading water in the middle of the Indian Ocean, because those animals had engineered a platform for him to stand on. But a coral reef is a platform in a much more profound sense: the mounds, plates, and crevices of the reef create a habitat for millions of other species, an undersea metropolis of immense diversity. To date, attempts to measure accurately the full diversity of reef ecosystems have been foiled by the complexity of these habitats; scientists now believe that somewhere between a million and ten million distinct species live in coral reefs around the world, despite the fact that those reefs only occupy one-tenth of one percent of the planet's surface. This is the Darwin Paradox: that such nutrient-poor waters could generate so much marvelous, improbable, heterogeneous life.

For forty years, ecologists have used the term "keystone species" to designate an organism that has a disproportionate impact on its ecosystem-a carnivore, for instance, who is the only predator of another species that would otherwise overwhelm the habitat with unchecked population growth. Remove the keystone predator and the habitat falls apart. But about twenty years ago, a scientist named Clive Jones at the Cary Inst.i.tute of Ecosystem Studies decided that ecology needed another term to describe a very specific kind of keystone species: the kind that actually creates the habitat itself. Jones called these organisms "ecosystem engineers." Beavers are the cla.s.sic example of ecosystem engineers. By felling poplars and willows to build dams, beavers single-handedly transform temperate forests into wetlands, which then attract and support a remarkable array of neighbors: pileated woodp.e.c.k.e.rs drilling nesting cavities into dead trees; wood ducks and Canada geese settling in abandoned beaver lodges; herons and kingfishers and swallows enjoying the benefits of the "artificial" pond, along with frogs, lizards, and other slow-water species like dragonflies, mussels, and aquatic beetles. As do those underwater colonies of coral, the beaver creates a platform that sustains an amazingly diverse a.s.semblage of life.

Platform building is, by definition, a kind of exercise in emergent behavior. The tiny Scleractinia polyp isn't actively trying to create an underwater Las Vegas, but nonetheless out of its steady labor-imbibing algae and erecting those aragonite skeletons-a higher-level system emerges. What had been a largely desolate stretch of nutrient-poor seawater is transformed into a glittering hub of activity. The beaver builds a dam to better protect itself against its predators, but that engineering has the emergent effect of creating a s.p.a.ce where kingfishers and dragonflies and beetles can make a life for themselves. The platform builders and ecosystem engineers do not just open a door in the adjacent possible. They build an entire new floor.

The cafeteria at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, had long been a site of productive shoptalk between the physicists, technicians, mathematicians, and proto-hackers who worked there. But the Monday lunchtime chatter on October 7, 1957, was unusually heated, thanks to the weekend headlines announcing the Soviet launch of Sputnik 1 Sputnik 1, the first man-made earth-orbiting satellite. Two young physicists, William Guier and George Weiffenbach, found themselves in a spirited discussion about the microwave signals that would likely be emanating from Sputnik Sputnik. After canva.s.sing some of their colleagues, it appeared that no one had bothered to come in over the weekend to see if Sputnik Sputnik 's signals could be picked up by the APL's equipment. Weiffenbach, as it turned out, was in the middle of a Ph.D. on microwave spectroscopy and had a 20 MHz receiver sitting in his office. 's signals could be picked up by the APL's equipment. Weiffenbach, as it turned out, was in the middle of a Ph.D. on microwave spectroscopy and had a 20 MHz receiver sitting in his office.

Guier and Weiffenbach spent the afternoon hunched over the receiver, listening for Sputnik Sputnik's audio fingerprint. To combat the doubters, who would inevitably question whether the whole launch was an elaborate hoax, a product of communist propaganda, the Soviets had engineered Sputnik Sputnik so that it would transmit an unusually accessible signal: an unbroken tone broadcast within 1 kHz of 20 MHz. By the end of the afternoon, Weiffenbach and Guier had a clear lock on it. The sound itself was a staccato pulse of electronic bleeps, but the context transformed it into the most marvelous music the two men had ever heard. It seemed unbelievable: sitting in a room in suburban Maryland, listening to man-made signals coming from s.p.a.ce. Word began to spread through the APL that the young physicists had captured so that it would transmit an unusually accessible signal: an unbroken tone broadcast within 1 kHz of 20 MHz. By the end of the afternoon, Weiffenbach and Guier had a clear lock on it. The sound itself was a staccato pulse of electronic bleeps, but the context transformed it into the most marvelous music the two men had ever heard. It seemed unbelievable: sitting in a room in suburban Maryland, listening to man-made signals coming from s.p.a.ce. Word began to spread through the APL that the young physicists had captured Sputnik Sputnik's signal, and a steady stream of visitors appeared at Weiffenbach's door to eavesdrop on the satellite's warble.

Realizing that they were listening to history, Guier and Weiffenbach hooked up the receiver to an audio amplifier and began recording the signal on audiotape. They included time stamps with each recording. As they listened and recorded, the two men realized that they could use the Doppler effect to calculate the speed at which the satellite was moving through s.p.a.ce. First observed more than a century before by the Austrian physicist Christian Doppler, the Doppler effect describes the predictable way a waveform's frequency changes when the source or the receiver is in motion. Imagine a speaker playing a single note, let's say the A above middle C, which sends out sound waves with a frequency of 440 Hz. If you mount the speaker on the hood of a car and have it driven toward you, the waves stack up on top of each other, making the interval between each of them shorter. When those compressed waves arrive in your eardrum, their perceived frequency is higher than 440 Hz. When the car backs up, the Doppler effect reverses, and the perceived note drops below A. You can hear the Doppler effect at work every time an ambulance drives past you with blaring sirens; as it pa.s.ses you by, the sound of its siren appears to slide down in pitch.

The Doppler effect has proved to be a remarkably versatile concept: it has been used to detect the expansion of the universe, to track thunderstorms, and to perform ultrasounds. Because Sputnik Sputnik was emitting a signal at a steady frequency, and because the microwave receiver was stationary, Guier and Weiffenbach realized that they could calculate the movement of the satellite based on the small but steady changes in the waveform they were capturing. Late that night, they remembered an additional mathematical trick: by a.n.a.lyzing the slope of the Doppler s.h.i.+ft, they could determine the point in was emitting a signal at a steady frequency, and because the microwave receiver was stationary, Guier and Weiffenbach realized that they could calculate the movement of the satellite based on the small but steady changes in the waveform they were capturing. Late that night, they remembered an additional mathematical trick: by a.n.a.lyzing the slope of the Doppler s.h.i.+ft, they could determine the point in Sputnik Sputnik's...o...b..t that was closest to the APL laboratories. Almost by accident, they had hit upon a technique not just for calculating the satellite's speed, but for actually mapping the trajectory of its...o...b..t. In a matter of hours, the two young scientists had gone from listening to measuring to tracking the Russian satellite.

Over the subsequent weeks, a loose network of scientists at APL coalesced around Guier and Weiffenbach's hunch, filling in details, researching the theoretical literature on orbiting bodies, and proposing technology improvements. Eventually, the APL's director approved funds to run the numbers on the lab's new UNIVAC computer. Within a few months of that first transmission, they had a complete description of Sputnik Sputnik's...o...b..t, inferred entirely from that simple 20 MHz signal. Guier and Weiffenbach had embarked on a quest that would define their professional careers, the "adventure of their lives," as they later called it. In the spring of 1958, Frank T. McClure, the legendary deputy director of the Applied Physics Laboratory, called Guier and Weiffenbach into his office. McLure had a confidential question to ask the men: If you could use the known location of a receiver on the ground to calculate the location of a satellite, McClure asked, could you reverse the problem? Could you calculate the location of a receiver on the ground if you knew the exact orbit of the satellite? Guier and Weiffenbach ran the logic through their heads for a few minutes, and then answered in the affirmative. In fact, deducing the location from a known orbit-instead of a stationary ground position-would make the results significantly more accurate. Without explaining his ultimate interest in the question, McClure told the two men to run a quick feasibility a.n.a.lysis. After a few furious days of crunching the numbers, Guier and Weiffenbach reported back: the "inverse problem," as they called it, was eminently solvable.

Soon, Guier and Weiffenbach would learn why the inverse problem was so important to McClure: the military was developing its Polaris nuclear missiles, designed to be launched from submarines. Calculating accurate trajectories for a missile attack required precise knowledge of the launch site's location. This was easy enough to determine on land-say, for a missile silo in Alaska-but it was fiendishly difficult in the case of a submarine floating somewhere in the Pacific Ocean. McClure's idea was to take the ingenious Sputnik Sputnik solution and flip it on its head. The military would establish the unknown location of its submarines by tracking the known location of satellites...o...b..ting above the earth. Just as sailors had used the stars to navigate for thousands of years, the military would steer its s.h.i.+ps using the artificial stars of satellite technology. solution and flip it on its head. The military would establish the unknown location of its submarines by tracking the known location of satellites...o...b..ting above the earth. Just as sailors had used the stars to navigate for thousands of years, the military would steer its s.h.i.+ps using the artificial stars of satellite technology.

The project was dubbed the Transit system. Just three years after Sputnik Sputnik's launch, there were five U.S. satellites in orbit, providing navigational data to the military. When Korean Air Lines Flight 007 was shot down in 1983 after drifting into Soviet airs.p.a.ce thanks to faulty, ground-based navigation beacons, Ronald Reagan declared that satellite-based navigation should be a "common good" open to civilian use. Around that time, the system took on its current name: Global Positioning System, or GPS. Half a century later, roughly thirty GPS satellites blanket the earth with navigational signals, providing guidance for everything from mobile phones to digital cameras to Airbus A380s.

If you wish to see firsthand the unpredictable power of an emergent platform, you need only look at what has happened to GPS over the past five years. The engineers that built the system-starting with Guier and Weiffenbach-created an entire ecosystem of unexpected utility. Frank McClure recognized that you could harness Guier and Weiffenbach's original insight to track nuclear submarines, but he had no inkling that fifty years later the same system would help teenagers to play elaborate games in urban centers, or climbers to explore treacherous mountain ranges, or photographers to upload their photos to Flickr maps. Like the Internet itself, GPS has turned out to have immense commercial value, and many for-profit firms were involved in building out the infrastructure that made it a reality. But the ideas ideas at the foundation of GPS-the notion of a satellite itself, the atomic clocks satellites rely on for accurate timing, and, of course, Guier and Weiffenbach's original insight with at the foundation of GPS-the notion of a satellite itself, the atomic clocks satellites rely on for accurate timing, and, of course, Guier and Weiffenbach's original insight with Sputnik Sputnik-all came out of the public sector. The generative nature of the GPS platform nicely mirrors the original environment that gave birth to it. When Guier and Weiffenbach were asked to explain how they had hit upon their Sputnik Sputnik revelation, they credited the intellectual habitat of the Applied Physics Lab more than their own particular talents: revelation, they credited the intellectual habitat of the Applied Physics Lab more than their own particular talents: APL was a superb environment for inquisitive young kids, and particularly so in the Research Center. It was an environment that encouraged people to think broadly and generally about task problems, and one in which inquisitive kids felt free to follow their curiosity. Equally important, it was an environment wherein kids, with an initial success, could turn to colleagues who were broadly expert in relevant fields, and particularly because of the genius of the Laboratory Directors.h.i.+p, colleagues who were also knowledgeable about hardware, weapons, and weapons needs.

In its own small way, the APL was a platform that encouraged and amplified hunches, that allowed those hunches to be connected with other minds that had relevant expertise. Out of that dense network, one of the most generative technological platforms of the twenty-first century took root. The APL was not a purely open platform, of course. There were military secrets involved, after all; and even if Guier and Weiffenbach had wanted to share their Sputnik Sputnik discovery with the world, it was much harder to distribute that breakthrough in an age when the hot new computer-the UNIVAC-took up an entire room. But behind those closed doors, William Guier and George Weiffenbach were the beneficiaries of an environment that encouraged the chance collisions between different fields, an environment that let two "kids" stumble across an idea at the cafeteria and build an entire career around it. discovery with the world, it was much harder to distribute that breakthrough in an age when the hot new computer-the UNIVAC-took up an entire room. But behind those closed doors, William Guier and George Weiffenbach were the beneficiaries of an environment that encouraged the chance collisions between different fields, an environment that let two "kids" stumble across an idea at the cafeteria and build an entire career around it.

Most hotbeds of innovation have similar physical s.p.a.ces a.s.sociated with them: the Homebrew Computing Club in Silicon Valley; Freud's Wednesday salon at 19 Bergga.s.se; the eighteenth-century English coffeehouse. All these s.p.a.ces were, in their own smaller-scale fas.h.i.+on, emergent platforms. Coffeehouse proprietors like Edward Lloyd or William Unwin were not trying to invent the modern publis.h.i.+ng industry or the insurance business; they weren't at all interested in fostering scientific advancement or political turmoil. They were just businessmen, trying to make enough sterling to feed their families, just like those beavers constructing lodges to keep their offspring safe. But the s.p.a.ces Lloyd and Unwin built turned out to have these unusual properties: they made people think differently, because they created an environment where different kinds of thoughts could productively collide and recombine.

The most generative platforms come in stacks, most conspicuously in the layered platform of the Web. (The phrase "platform stack" itself is part of the common parlance of modern programming.) The Web can be imagined as a kind of archaeological site, with layers upon layers of platforms buried beneath every page. Tim Berners-Lee was able to single-handedly design a new medium because he could freely build on top of the open protocols of the Internet platform. He didn't have to engineer an entire system for communicating between computers spread across the planet; that problem had been solved decades before. All he had to do was build a standard framework for describing hypertext pages (HTML) and sharing them via existing Internet channels (HTTP). Even HTML was based on another existing platform, SGML, which had been developed at IBM in the 1960s. Fourteen years later, when Hurley, Chen, and Karim sat down to create YouTube, they built the service by st.i.tching together elements from three different platforms: the Web itself, of course, but also Adobe's Flash platform, which handled all the video playback, and the programming language Javascript, which allowed end users to embed video clips on their own sites. Their ability to build on top of these existing platforms explains why three guys could build YouTube in six months, while an army of expert committees and electronics companies took twenty years to make HDTV a reality.

Culture, too, relies on stacked platforms of information. Kuhn's paradigms of research are the scientific world's equivalent of a software platform: a set of rules and conventions that govern the definition of terms, the collection of data, and the boundaries of inquiry for a particular field. Kuhn's argument has often been mistaken as a defense of a purely relativistic account of science, where empirical "truth" is always in quotation marks because paradigms replace each other over time. (The apparent solidity of scientific truth, in this account, is merely a kind of hologram produced by the apparatus of the paradigm.) But modern scientific paradigms are rarely overthrown. Instead, they are built upon. They create a platform