One more thing as we solicit comments on this video. I am thinking that this presentation by Sagan is so clear and so basic that it ought to be part of a background "reading list" for anyone beginning the study of Epicurus in general or Epicurean physics in particular. The linking of these issues to problems with Pythagorus, Plato, Aristotle, and Christianity is just priceless. I can't recall whether he mentions "Stoics" but they are clearly implicated negatively too.
It's really frustrating that Sagan does not mention Epicurus by name, and mentioned that Epicurus fought back against the same idealist gang that Sagan is criticizing. But again the implications are clear once you scratch the surface of the subject.
No doubt there are other videos and materials which make this same point, but this is the best I am aware of. Anyone who reviews this and thinks "I've seen _______ make the very same point in another video....." - Please post a link or info where we can try to find it and add to a "basics" list.