QUOTE : If we were to construct a similar map for society, it would have to include each person’s professional and personal interests and chart everyone she or he knew. It would make Milgram’s experiment seem clumsy and obsolete by allowing us to find, in seconds, the shortest path to any person in the world. It would be a must-use tool for everyone from politicians to salespeople and epidemiologists. Of course, such a social search engine is impossible to build, since it would take at least a lifetime to interrogate all 6 billion people on the earth to learn about their friends and acquaintances.