The big question for this segment is, how did information networks function and expand in human history? [MUSIC] Innovation is emergence. Things and ideas come together in new arrangements that have new emergent properties, that can generate more new arrangements, that have even newer emergent properties. Where you have the right Goldilocks conditions, innovation can build on innovation. In human history, innovation we've seen was driven by collective learning. And as a general rule, collective learning seems to have ensured that the pace of innovation would accelerate over the course of human history. But sometimes, and in some places, innovation slowed, stagnated, or even reversed. So what factors increased the likelihood of innovations? And, what factors blocked innovation? The burgeoning field of network theory offers some interesting insights into this important question. In a network, you have nodes, think people. And you have links between the nodes, think of a marriage, or exchanging money for coffee, or giving your grandparent a birthday present. Network theory studies the rules that determine how efficiently, and how fast, ideas circulate within networks. Rule number one is that the number of links increases much faster than the number of nodes. Translation? Double the size of a human community and you may triple or quadruple the number of ideas being exchanged. Collective learning seems to become much more powerful as human communities grow in size. Think what that means for today's world of more than 7 billion people. Rule number two, technologies of communication really matter. 10,000 years ago ideas spread at walking place. Eventually, horse couriers and ships speeded up the movement of information, and writing and printing improved information storage. In the 19th century, beginning with the telegraph, we learned how to exchange information at the speed of light, right around the world. Better communications allow ideas to diffuse faster and further. Some other network rules are subtler. If most links are between neighbors, say in a village, an idea may take a long time to spread to other communities. But if just a few of the links are long distance, think of merchants or travelers or peddlers or migrant workers, ideas can travel further and faster. So, just a few long distance links seem to make the world smaller. Which is why in network theory, this idea is called the small-world theorem. Then there are hubs. These are nodes that are very well connected, think cities or think Google. A lot of ideas flow through hubs. If you want to be well connected, link yourself fast to a hub. That explains why hubs seem to add links faster and faster. While isolated nodes, think of remote villages, seem to stay isolated. Hubs hum with ideas and information and they ooze innovation. Taken together, these ideas tell us that collective learning will drive innovation with increasing power as societies get larger and better connected, as communications technologies improve, as the number of long range links increases, and as hub regions, such as cities, multiply. Large exchange networks not only encourage the synergies that lie behind most innovations, they also diffuse them more rapidly and over larger areas. This helps explain why the pace of innovation has accelerated in the last 10,000 years as agricultural societies increased in size, as long distance trade expanded, and as towns and cities multiplied. The Eurasian Silk Roads, which linked societies from China to the Mediterranean, are a classic example of the power of long distance exchange networks to encourage innovation. The Silk Roads diffused silk making technology, paper making, and gunpowder from China to the West. While new art styles, coins, and glassware traveled in the opposite direction. Like the Internet today, they seemed to make the world smaller. By the same token, innovations develop more slowly in regions with fewer people and smaller and less efficient exchange networks. That's why we generally expect more innovation from cities than from villages. Other forces could also stifle innovation. In traditional societies, where life often seemed pretty precarious, it was usually easiest to see the destructive side of change. So governments, religious leaders, artisans, and peasants usually feared change in traditional societies because it destabilize things. That's why the first Han emperor burned books. It's why many church leaders burned heretics or imprisoned scientists such as Galileo. Today, when innovation is usually seen more positively, it's all too easy to forget that most societies feared innovation like the plague, even though, behind people's backs, collective learning kept spinning off innovations that would eventually transform all human societies. So the rules of networks and the synergy of collective learning could help us explain why, despite the conservative of most traditional societies, innovations have popped up throughout human history. In the last 500 years, the pace of innovation accelerated. For the first time in world history, new trading networks, dominated by European merchants and governments, linked all parts of the world into a single, global exchange system, in which ideas, goods, religions, and even diseases, circulated faster and over greater distances than ever before. Merchants made colossal profits trading goods such as silver or spices or slaves from one part of the world to another. These profits encouraged the search for new and more efficient ways of making and exchanging commodities. Commerce and capitalism emerged as increasingly powerful drivers of innovation. As governments, merchants, and manufacturers realized that innovative methods of production and transportation could increase their profits. The circulation of new ideas throughout the world encouraged the emergence of modern forms of science during the Scientific Revolution. In the 19th century, innovation became, for the very first time, a major goal of governments, universities, research institutions, and officials, as well as of merchants and traders. Most modern societies began to treat innovation as a good thing, rather than a threat. Though even today, many groups continue to fear the new. Multiplying drivers of innovation in recent centuries help explain the explosion of technological, financial, political and organizational innovations that drove the Industrial Revolution. These innovations would lay the foundations for today's world. [MUSIC]
