His “Crash Course in Astronomy” is pretty good — the first part of this talk is universally (see what I did there?) applicable, since it’s a solid general description of science and how it works.
Of course, the last part is all this astronomy stuff — I suspect that he’ll avoid talking about cells and molecules for the next 11 episodes. Which is OK, I guess, if you’re interested in rocks and gas and plasma. And massive amounts of nothingness.