Despite the name of this book, it is really a biography about Galileo through the adult years of his life. It chronicles the positions that Galileo held, where he held them, and what scientific discoveries he made that have shaped modern science. Behind all the science, however, were Galileo's family and friends. Galileo had two daughters, which were sent at an early age to the convent, and a son. He made friends in the religious community, as well as with the Medici family, becoming an official mathematician of the Florence Medici factor.
Galileo and his eldest daughter were very close and wrote letters to each other on a very regular basis (she was not allowed to leave the convent and in his poor health, he couldn't always visit). Unfortunately, only her letters to him were saved. It is believed that his letters to her were burned or buried. The author uses her letters to her father to guide the biography and indicate how she felt when Galileo was going through some of his more troublesome times: namely, the inquisition against him that essentially put him under house arrest after supporting the idea that the Earth revolves around the Sun.
While parts of this book moved very slowly, overall it was interesting. There's even a surprise at the ending which wraps the book up very nicely. Having just been in Florence, it was neat to get a perspective of what the city was like 400+ years ago.
First Line: "We are terribly saddened by the death of your cherished sister, our dear aunt: but our sorrow at losing her is as nothing compared to our concern for your sake, because your suffering would be all the greater, Sire, as truly you have no one else left in your world, now that she, who could not have been more precious to you, has departed, and therefore we can only imagine how you sustain the severity of such a sudden and completely unexpected blow."