What does it mean to make a Discovery?

What is the role of discovery in human history? As we trace a line over periods of discovery, consider the lasting impact of each, as that is what makes a discovery important. From Plato and Aristotle, the fathers of modern philosophy; to the Silk Road, which was born in the east but deeply impacted the west (if for no other reason than its role in contributing to the spread of the Plague); to the Enlightenment and changing views of faith; to the discovery of the Americas; to a renaissance for black artists in Harlem; to the Industrial Revolution, which radically changed the way that people lived and how the world works, for better and worse. The thread of change ties these and hundreds of other important discoveries together, and the overarching impetuses and results are our focus.