This is a book about time, both the physics of time, and how our brains understand and manipulate time.
Many animals have the ability to learn from experience, and to project how to hunt, hide from predators, and other things necessary for higher animals to survive in their relatively complex worlds. Humans are the only animals whom we are certain can reflect on the past, plan for the less immediate future, and imagine things that don't have a lot of connection to the real, immediate world. The list of animals whom we have some evidence may share this ability has expanded over my lifetime, but it still doesn't seem to be a common ability.
