[cameldrv]

You can also watch the original lecture. This is one of my very favorite explanations of anything:

http://www.vega.org.uk/video/programme/46

This explanation starts at about 30 minutes, but I highly recommend watching from the beginning.

[yesenadam]

Thanks! I hadn't seen these. There are 4 Feynman lectures on this page[0], the Douglas Robb Memorial Lectures, of which you linked to the second.

http://www.vega.org.uk/video/subseries/8

1. A gentle lead-in to the subject, Feynman starts by discussing photons and their properties. 2. What are reflection and transmission, and how do they work? 3. Feynman diagrams and the intricacies of particle interaction. 4. What does it mean, and where is it all leading?

The site has many other science videos too:

http://www.vega.org.uk/video/series/5

[yesenadam]

Update: have now watched 3 of the 4 videos. Can see why you loved it so much! I've watched a lot of Feynman talks and lectures, and read most of his books. ..but this has particularly good explanations of the material, distinctly clearer than a couple of talks of his I'd seen before. Plus a few priceless references to NZ and the NZ national character! (filmed Auckland 1979)