Whoops. Lecture 5's link is incorrect. It points to lecture 4. Here's the correct one:

Lecture 5: The Distinction of Past and Future http://www.youtube.com/watch?v=Ozjb6kQvBpc

And thanks to fjarlk for pointing out that I accidentally omitted Part 7!

Lecture 7: Seeking New Laws http://www.youtube.com/watch?v=MIN_-Flswy0