'A kind of choose-your-own-adventure using fonts: paragraphs are set in type of differing sizes depending on their importance' - The Bookseller 'Engaging … there is a great deal to recommend about Sparrow’s book for those wanting an approachable primer to this hugely complex question' - BBC Sky at Night 'An invaluable resource … The explanations are clear, inspiring and memorable, and the information laid out in an easy-to-follow narrative. Definitely recommended' - SF2 Concatenation