Feynman only taught physics. Sal Khan teaches maths, astrophysics, economics, history, etc etc... The potential for misinformation from someone who is teaching

Feynman only taught physics. Sal Khan teaches maths, astrophysics, economics, history, etc etc... The potential for misinformation from someone who is teaching a subject that they are not an expert in, and have just "understood it quickly" is quite worrying. he has been criticised on this before, see http://www.nas.org/polArticles.cfm?Doc_Id=2029 http://www.nas.org/polArticles.cfm?Doc_Id=2029 Economics is a lot like maths, and there is crossover so it's no surprise that he is good at both. But History is a different kind of subject. If he is really irreplaceable, then there are severe limits on it. I hope and expect that even if Sal Khan is a trailblazer, others can do follow his example.