(April 23, 2012) Leonard Susskind begins to discuss particle mechanics and the role that they play in the special theory of relativity. This includes how particles move, the idea of momentum, and some topics on energy. 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. In this course, 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.