Formerly a physics professor at Brandeis University, Kleitman was encouraged by Paul Erdős to change his field of study to mathematics. Perhaps humorously, Erdős once asked him, "Why are you only a physicist?"
Formerly a physics professor at Brandeis University, Kleitman was encouraged by Paul Erdős to transition his research into mathematics. Perhaps amusingly, Erdős once questioned, "Why do you limit yourself to physics?"