in the movie amadeus salerie asked himself if he could identify mozart from among the 100 guests because perhaps genius is written on the face. much to his surprise he found out that it was not when he saw a crude mozart, giggling on the floor, telling dirty jokes. i have the same feeling. when i watch documentaries of these ingenious physicists, steven weinberg, michael green, edward witten, michio kaku, lisa randall to name just a few perfectly at random, they look like completely ordinary people, nothing special about them, no genius is written on the face. on the other hand, sometimes you can tell someone is stupid just by looking at them. i realize that it's not politically correct to say that, but it's true.