On this edition of our program, we speak with the California-based physician and writer Lucy Kalanithi. Her late husband Paul, also a physician, wrote the bestselling memoir, "When Breath Becomes Air," in the final months of his life. (He died of lung cancer before his 40th birthday.) As was noted of this short yet powerful book by The Boston Globe: "Paul Kalanithi's posthumous memoir...possesses the gravity and wisdom of an ancient Greek tragedy.... [Kalanithi] delivers his chronicle in austere