The Newtonian model of Physics posits absolute time, and relies upon the classical mechanics of Euclidean Geometry. In the early 20th century, scientists began to interrogate this model, intrigued by the possibility of a dimension in which space and time overlap. Intended for readers curious about Relativity but not trained to understand the mathematics behind it, this text is Einstein’s philosophical explanation of the idea that changed the way we understand the physics of space and time.