It would be hard to point to a precise moment when the world became “global.” After all, people have been communicating on a global scale for tens of thousands of years – the fact that early humans managed to travel from Africa through Eurasia and settle the Americas and Australia represents globalization of a rather profound sort. Of course, the pace of communication started out very slow indeed. Even a very good idea, such as the domestication of the horse, probably took a thousand years to reach all corners of Europe and Asia. Political integration advanced the flow of ideas. When the Roman Empire connected much of Europe and the Mediterranean, it also created a cultural world that was linked by technologies, language, and eventually Christianity. The last great frontiers were the oceans: the New World did not have horses or Christianity (or smallpox, for that matter) until the Spanish introduced them in the late fifteenth century. Over the past century, however, the rate of global communication has advanced exponentially. New communications technologies are one obvious reason. To appreciate the pace of change, try taking the big innovations and working backward.