How will the universe end? Will there be a reversal of the Big Bang, or will all matter have spread out so much that it slowly suffers from heat death? Or will one of the even more bizarre alternatives occur? Mack, an astrophysicist, lays out all the possibilities and their likelihoods (none, it should be noted, include the survival of any life in the universe whatsoever).

This is one of a handful of books I've read in recent years which touch on the origins and demise of the universe, but because I lack a background in advance physics and cosmology I often have a challenging time keeping all the science in my brain between reads. My hope is that periodic reviewing will help some of the details to stick. Though I was confidently treading water during the first half of the book, I did begin to feel as though I were sinking in the latter half. Mack's light-hearted tone and humorous asides set a mood of a casual conversation, which was appreciated. Oh, and I absolutely delight in the idea that, because quarks resist solitude, if you try to split two quarks you get instead four quarks. ( )

(4.5 Stars)

This book was very good. It was so helpful in explaining some pretty deep concepts in a way that is attainable, understandable, and even conversational, without talking down to the reader. The Narrator has a great cadence and really kept me engaged and interested.

I won't say that I no longer have existential dread over the end of the universe, but at least I know I'm in good company!

People who like astrophysics, science, theoretical research, or snarky strong female voices will love this book. ( )

To explain all the ways the universe might end, this takes you through lots of astrophysical concepts. Accessible to readers as scientifically illiterate as me. I still can’t cope with Boltzmann brains, though.

Who would have guessed that contemplating the big crunch, heat death, the big rip, vacuum decay, and bounce could be so entertaining? Astrophysicist Katie Mack has devoted her life to thinking about the end of everything (that is, the universe) and has somehow maintained her humor and sense of awe. These help the reader confront that, as sure as our universe began, it will end. There’s nothing we can do to stop that happening, and the certainty that all but one of these scenarios will happen long after there are humans to be aware of it is a small comfort. (The exception, the big rip, could happen any moment but will happen faster than our nerves can pass the sensation to our brains, so no worries).
But if we can’t prevent it, why think about it? In the final chapter, Mack poses this question to several colleagues. Most admit it makes them sad, but one said: “I’m delighted that we get to live at a time in the universe when we can see dark energy and not be ripped apart by it. But that means the whole point is that you understand it, and then you enjoy it, and then . . . ‘So long and thanks for all the fish.’ Cool.”
That’s the sense this book left me with as well. The remaining disconnect between the Concordance Model in cosmology and the Standard Model in particle physics, along with the fact that weak gravity doesn’t fit well with either, isn’t disturbing but fascinating. There’s more out there to explore. And the tools we use for that, from the Large Hadron Collider deep under the Alps to the James Webb Space Telescope, are exciting, even for an interested layman who forgot the little calculus he once learned, so he takes the math on faith.
Ah yes, that troublesome word, faith. We live in a time when it’s fashionable to bash religion, contrasting it with “science,” understood as the realm of facts based on observation. Yet when Mack asks “how to make advances in areas of theory in which experimental evidence may never appear,” I wonder if these two modes of inquiry, science and theology, are as incompatible as many think. Mack concedes that arguments rage about “whether or not untestable theories should even be called science.”
Whether science or not, I’m a fan. As Carl Sagan said (quoted here by Mack): “We are a way for the cosmos to know itself.” I’m happy to be along for the ride. Although I totally get it when Mack admits the possibility that spacetime isn’t real makes her queasy. ( )

I enjoyed this book very much. Dr. Mack takes on a huge question -- what's the fate of the Universe? -- and presents, in detail, the possibilities, the evidence for them, and the likeliest among them. To do that, she covers a good deal of the math and science in astrophysics and cosmology.

She writes very clearly. She's got a great nerd sense of humor. She's also passionately, genuinely interested in her field and in the work that she does. That shines in her book.

I especially enjoy good science writing. Dr. Mack is as good at explaining cosmology as Stephen Hawking and Carl Sagan were.

I hope she publishes more for a general audience. ( )