Galileo's Daughter: A Historical Memoir of Science, Faith and Love. It is based on the surviving letters of Galileo Galilei's daughter, the nun Suor Maria Celeste and explores the relationship between Galileo and his daughter.
I read this book while sailing the Mediterranean and will never forget how poetic and philosophical it was. An amazing read. My only regret is that I left it on the boat - it should live forever on my book shelf