Q. Nearly 50 years after Richard Feynman gave these lectures, why are they still relevant today?
A. Feynman brought a level of insight, enthusiasm and trenchant wit to the exposition of the fundamental laws of physics that is unsurpassed. These lectures come from the height of his “pedagogical period,” shortly after he finished his “Feynman Lectures” books. As for why they are still relevant, I addressed that in one of my commentaries. Here is a quote from my commentary on the last lecture:
“The laws of physics that Feynman has been describing are just as fresh and powerful as they were in 1964, or indeed decades earlier, when they were first discovered. In contrast a 50-year-old lecture series in biology, chemistry, computer science or the social sciences would be of historical interest only. For better or worse, the laws of physics don't change (no matter how much we may sometimes wish they would). Now, as in Feynman's day, they form the basis of all the other sciences, and Feynman's explanations are as fresh as any lectures in a classroom today. From time to time, I've added some modern perspective, occasionally correcting one of Feynman's remarks that proved incorrect in later years.”
There are also people who I think follow the cult of "celebrity". A lot of people who have very little inkling of understanding of Stephen Hawking's work, for example, still buy his books and flock to his appearance as if he's a rock star. I would think that Feynman legend continues to grow even after his death, and that helps to cultivate more "cult" following.
In any case, if you missed it, I reported on the availability of the Feynman lectures online a while back, thanks to Bill Gates.