The document discusses how disruptive technologies like railroads and the telegraph re-shaped the world during the Gilded Age. It notes that we are currently in a time of volatility, uncertainty, and opportunity due to new disruptive technologies that allow for frictionless economies where new people can create new value for new customers. The document promotes the lean startup approach of using customer interaction and segmentation, viability testing, and data/actionable metrics to help entrepreneurs surf uncertainty and build disruptive businesses.