Does anyone know what Feynman was referring to in this interview which appears at the beginning of The Feynman Tips on Physics?  Note that he is referring to something that did not appear in the Feynman lectures.


  I didn't like to do the second year, because I didn't think I had
  great ideas about how to present the second year.  I felt that I
  didn't have a good idea on how to do lectures on electrodynamics. 
  But, you see, in these challenges that had existed before about
  lectures, they had challenged me to explain relativity, challenged me
  to explain quantum mechanics, challenged me to explain the relation of
  mathematics to physics, the conservation of energy.  I answered every
  challenge.  But there was one challenge which nobody asked, which I
  had set myself, because I didn't know how to do it.  I've never
  succeeded yet.  Now I think I know how to do it.  I haven't done it,
  but I'll do it someday.  And that is this: How would you explain
  Maxwell's equations?  How would you explain the laws of electricity
  and magnetism to a layman, almost a layman, a very intelligent person,
  in an hour lecture?  How do you do it?  I've never solved it.  Okay,
  so give me two hours of lecture.  But it should be done in an hour of
  lecture, somehow -- or two hours.
  
  Anyhow I've now cooked up a much better way of presenting the electrodynamics, a much more original and much more powerful way than
  is in the book.  But at that time I had no new way, and I complained
  that I had nothing extra to contribute for myself.  But they said, "Do
  it anyway," and they talked me into it, so I did.


Did this approach to teaching electrodynamics appear in any of his later writing?

I spent a long time researching this question for Carver Mead (mentioned by Art Brown) in 2008, because we were both curious what Feynman meant. Carver thought Feynman's "better way of presenting electrodynamics" would be something along the lines of his own "Collective Electrodynamics," but that turned out to be only partly true, as I discovered in four pages of Feynman's notes, written during the year he was teaching the FLP lectures on electrodynamics, which briefly explains his new program. [These notes can be found in The Caltech Archives: Box 62, Folder 8 of The Feynman Papers, "Working Notes And Calculations: Alternate Way to Handle Electrodynamics, 13 Dec 1963."] I asked Matt Sands if he knew anything about it, and he told me that in about the middle of the 2nd year of the FLP lectures, Feynman started to complain that he was disappointed that he had been unable to be more original.  He explained that he thought he had now found the "right way to do it" -- unfortunately too late. He said that he would start with the vector and scalar potentials,  then everything would be much simpler and more transparent. The notes are much more detailed than that. Unfortunately I don't have the right to publish them myself (without asking Caltech's permission)... but there is a plan to digitize the Feynman Papers and put them online - funding is being sought for that now.

Mike Gottlieb:
Editor, The Feynman Lectures on Physics & 
Co-author, Feynman's Tips on Physics

P.S. As mentioned in my comment below, the notes have been posted. They can now be found here.
