The planet started shrinking as the various places around the world became more closely connected through transportation and communication. When a person became able to talk to someone directly across the continent which used to take months to cross,
it shrinks the distance between them. When someone can circle the globe in a day in a plane, suddenly a long sea voyage is no longer required and the distance is shrunk. Consider now with all of the connectivity we have: how close everyone has become. Explain.