Traditionally, we have understood historical movement as either a line or a circle. We are either progressing towards the truth, or trapped in an endless loop. In this talk to his Chinese high school students, Professor Jiang proposes a new theory, which he calls "the oceanic currents of history."When we examine the fall and decline of global empires, a pattern emerges. As the empire expands, it draws once isolated regions into its orbit. The empire allows these regions to become more prosperous and sophisticated through trade and conflict. Prosperity increases the population in these borderlands, which forces them to expand and come into direct conflict with the empire. Sometimes, these people of the borderlands will overwhelm the empire, and become a new empire.