Lecture 1 of Leonard Susskind's Modern Physics concentrating on General Relativity. Recorded September 22, 2008 at Stanford University. This Stanford Continuing Studies course is the fourth of a six-quarter sequence of classes exploring the essential theoretical foundations of modern physics. The topics covered in this course focus on classical mechanics. Leonard Susskind is the Felix Bloch Professor of Physics at Stanford University. Stanford Continuing Studies: http://continuingstudies.stanford.edu/ About Leonard Susskind: http://www.stanford.edu/dept/physics/people/faculty/susskind_leonard.html Stanford University Channel on YouTube: http://www.youtube.com/stanford