Don't let the "YA" designation put you off this book -- as an adult who has a low tolerance for teen-oriented novels, I really enjoyed his one. The coming-of-age story isn't particularly interesting, but it merely provides a backdrop for the meat of the novel: a thought experiment about the global, environmental, and social effects of a world where the earth's rotation starts slowing down. How humans cope with the changes, and the tertiary effects that make logical sense but wouldn't have occurred to me, are fascinating to consider. A quick read, it's worth picking up, especially if you enjoy post-environmental-apocalypse novels like "The Road" and "Station Eleven."