"What If? 2" by Randall Munroe. It's more good stuff of the same flavor as the first "What If?"
There are some features new to this book that are not found in the previous book, most notably a handy index at the end. Just in case if you were look for all the pages that mentions "moon", or perhaps that one specific page for "moon, destroying". While the first book had mostly standalone chapters that can be read in any order, this one has a few recurring jokes that are best read sequentially (including "Things you should not do" and "What you'd expect the answer to be / What the answer actually is"). There are also a few references to the first book, one of which involving time travel with a great punchline. It's a proper sequel to the first book.
Overall, this book is everything I expected, even though it seemed to not include the content that were scattered in a less convenient place. Licensing issues perhaps? Definitely looking forward to volume 3.
Be sure to also watch Randall Munroe's talk on this book, which included a lot of behind the scene bits on the research that went into this book: https://www.youtube.com/watch?v=5qJlsEz07eQ
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