(May 21, 2012) Leonard Susskind reviews some of the heavy mathematics from the previous lecture and discusses how at times complicated mathematics is the only way to explain high level physics, briefly sharing his thoughts on how and where math and nature collide. In 1905, while only twenty-six years old, Albert Einstein published "On the Electrodynamics of Moving Bodies" and effectively extended classical laws of relativity to all laws of physics, even electrodynamics. Professor Susskind takes a close look at the special theory of relativity and also at classical field theory. Concepts addressed here include space-time and four-dimensional space-time, electromagnetic fields and their application to Maxwell's equations.