5.0

In the last chapter, Ord looks to the astoundingly large expanses of space and time humanity could one day traverse. Reading about it filled me with awe and wonder in a way nothing else I've read ever has. I especially liked this passage:
But if we could reach just one nearby star and establish a settlement, this entire galaxy would open up to us. For then the process could repeat, using the resources of our new settlement to build more spacecraft, and its sun to power them. If we could travel just six light years at a time, then almost all the stars of our galaxy would be reachable. Each star system, including our own, would need to settle just the few nearest stars, and the entire galaxy would eventually fill with life.

The final chapter drove home the urgency and importance of not squandering that future.