My wife, Carrie Rinker-Schaeffer (now associate professor in surgery, the University of Chicago) got her PhD at the University of Kentucky starting in 1986. One of her fellow biochemistry students was a very bright fellow by the name of Bharath Srinivasan. One day, Bharath was arguing with someone about a point of physics and announced, "There is only one person in the world to ask about this, and that is Richard Feynman." So he got on the phone and called Feynman's office at Caltech, and miraculously got through to him. In a tumble of words and without pausing, he said, "Professor Feynman my name is Bharath Srinivasan and I am a grad student at the University of Kentucky and we have this argument about physics and you are the only one who can help please don't hang up on me..." Feynman told him to go ahead and Bharath asked, "Is time a vector or a scalar quantity?" Feynman said something like, "You know, that's a very interesting question..." and proceeded to talk at some length on the subject. (Unfortunately, I don't know how the discussion went.) Then Feynman asked if Bharath were from India, which he was, and they talked for a while about that country, which Feynman apparently had a great interest in. Then they talked about graduate education in the United States and a bunch of other topics. Finally, after about 2 hours, Feynman indicated that he had to go, and Bharath's response was, "Oh, Dr. Feynman, this has been great and thanks for talking to me. May I call you again some time?" Feynman replied, "No."