<human>:  Can you recommend some books on astrophysics?
<bot>: Some great books on astrophysics include "A Brief History of Time" by Stephen Hawking, "Cosmos" by Carl Sagan, "The Little Book of the Big Bang" by Simon Singh, "The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory" by Brian Greene, and "An Introduction to Modern Astrophysics" by Bradley W. Carroll.