Spring, 2012
In 1905, while only twentysix 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, we will take a close look at the special theory of relativity and also at classical field theory. Concepts addressed here will include fourdimensional spacetime, electromagnetic fields, and Maxwell's equations. (Image credit: KIPAC at Stanford University)
Lectures in this Course

The Lorentz transformation
In the first lecture of the course Professor Susskind introduces the original principle of relativity  also known as Galilean Invariance  and discusses inertial reference frames and simultaneity. He then derives the Lorentz transformation of... [more] 
Adding velocities
Professor Susskind starts with a brief review of the Lorentz transformation, and moves on to derive the relativistic velocity addition formula. He then discusses invariant intervals, propertime and distance, and light cones. Note: this is only a 1... [more] 
Relativistic laws of motion and E = mc^2^
Professor Susskind begins with a review of space and timelike intervals, and explains how these intervals relate to causality and action at a distance. He then introduces spacetime fourvectors and fourvelocity in particular. After presenting... [more] 
Classical field theory
Professor Susskind moves on from relativity to introduce classical field theory. The most commonly studied classical field is the electromagnetic field; however, we will start with a less complex field  one in which the field values only depends on... [more] 
Particles and fields
Professor Susskind begins with a discussion of how, in the case of charged particle in an electromagnetic field, the particle affects the field and viceversa. This effect arises from cross terms in the Lagrangian. He then derives the action,... [more] 
The Lorentz force law
After a review of Einstein & Minkowski notation and an introduction to tensors, Professor Susskind derives the relativistic Lorentz force law from the Lagrangian for a particle in a vector field. At the end of the lecture, he introduces the the... [more] 
The fundamental principles of physical laws
Professor Susskind elaborates on the four fundamental principles that apply to all physical laws. He then reviews the derivation of the Lorentz force law as an example of the application of these principles. The lecture closes with an introduction... [more] 
Maxwell's equations
After a brief review of gauge invariance, Professor Susskind describes the introductory paragraph of Einstein's 1905 paper "On the Electrodynamics of Moving Bodies," and derives the results of the paragraph in terms of the relativistic... [more] 
Lagrangian for Maxwell's equations
Professor Susskind begins the lecture by solving Maxwell's equations for electromagnetic plane waves. He then uses the principles of action, locality and Lorentz invariance to develop the Lagrangian for electrodynamics for the special case without... [more] 
Connection between classical mechanics and field theory
Professor Susskind begins the final lecture with a review and comparison of the three different concepts of momentum: mechanical momentum from Newtonian mechanics, canonical momentum from the Lagrangian formulation of mechanics, and momentum that is... [more]