18 January 2022
Katie Mack is the incoming Hawking Chair in Cosmology and Science Communication at the Perimeter Institute in Waterloo, Ontario. She has written an excellent book about the end of the universe, The End of Everything. In it, she explains with wit and insight, four different ways the universe could die. I read it a year after I took an introductory astronomy course, and found that it both covered similar terrain to the cosmological concepts I learned there, but presented them in different language, with different emphases, and with the guiding question, What happens at the end of the world? She details the evidence for and against various scenarios, including the Big Crunch, the Big Rip, the Heat Death of the universe, and a rules-rewriting process called Vacuum Decay. None of these are worth worrying about (because you can’t do anything about any of them), but they are worth learning about. At least I think so, and so does Dr. Mack. Perhaps it just frees us up to focus on issues we actually can control, or perhaps it enriches our experience as citizens of the universe, or perhaps it provides a learning framework that can reveal the way the universe really works, and that may ultimately provide tangible benefits to humanity (or our descendants). She openly grapples with the philosophical implications, even if they are cold comfort. Regardless, it’s a fascinating journey, and Katie Mack is an excellent guide, writing about the destruction of everything we know and hold dear with a sense of humor, elegant diagrams, and select interviews with other astrophysicists. I think the book is strongest when she is enthusiastically describing that which she knows well, but the addition of two chapters at the end consisting mainly of reflective interviews with peers adds a sense of grounding and validation to the work (but at the cost of diluting Mack’s own distinctive voice). Enjoyable, especially paired with Emma Chapman’s First Light, about the processes that birthed stars at the beginning of the universe. Bookends to the story of the cosmos, you might say.