Mathematical and Quantum Aspects of Relativity and Cosmology Book

Very good survey of cosmology as it regards the age of the universe. This book does a good job of explaining why cosmologists are so confident that the universe is 13.7 billion years old. Oops, was that a spoiler? The author does a good job of explaining several details that are glossed over in other, poorer tellings of the history of science. For example, I now feel like I understand the reason for the early confusion about the value of the Hubble constant; namely that there are multiple types of Cepheids, and there differences were not appreciated at first.