Six Degrees by Duncan Watts is named after the Six Degrees of Kavin Bacon Game in which players choose an actor and then try to connect him to Kevin Bacon.

For example, John Wayne. John Wayne was in How the West was Won with Eli Wallach. Eli Wallach was in Mystic River with Kevin Bacon. So John Wayne has a Bacon number of 2.

The book is about network theory and the radical proposition that there are properties of networks that are true regardless of the kind of network. For example, a computer network, the power grid and the network of Hollywood actors all have things in common. An important corollary is that by studying networks that are familiar — we can discover truths about unknown or less familiar networks.

If you like computers, science or math, you should read this book.