The End of Everything (Astrophysically Speaking) by Katie Mack
In case these times weren’t providing enough anxiety, astrophysicist Katie Mack has arrived on the scene with something else for you to worry about — the end of the universe. More precisely, in The End of Everything (Astrophysically Speaking) (2020), Mack explores five ways the universe might die: The Big Crunch, Heat Death, The Big Rip, Vacuum Decay, and a Bounce. Luckily, most won’t be coming along for some billions of years, so you can probably still get in everything you’ve been planning on — cleaning out the garage, binging that TV show, learning to make cocktails, etc. (Those of us with TBR shelves, though, are out of luck — billions of years just won’t cut it.)
Mack opens with a tour of our current understanding of the universe’s lifetime, from the Big Bang almost 14 billion years ago up to now. Then each apocalyptic scenario gets its own chapter detailing the science behind the theory and presenting the experimental and observational evidence for or against the theory. Given that we’re in the realm here of theoretical physics/cosmology, none of these scenarios can be absolutely ruled out, leaving Mack to present the evidence as leading to a “more” or “less” likely result. She also explains how our advancing technology might be able to prove or disprove some of the theories in the relatively near future (some may be well beyond out experimental capabilities for generations if not forever).
The opening tour of the universe’s birth and development to its current stage is nicely concise and wonderfully lucid, covering topics such as the beginning singularity, the brief time all four forces were a single force, cosmic inflation, the birth of matter starting with quarks and then building up into protons and neutrons and then elements like helium and lithium, and eventually up to the large structures like suns and galaxies.
The first end of the universe section goes into more detail on the expansion of the galaxy and what would happen if that expansion reverses (and why that might occur) ending us all in a “Big Crunch.” The next two sections of The End of Everything (Astrophysically Speaking) deal more closely with dark energy and entropy and how they might lead to a relatively quiet Heat Death (as Mack puts it, the “slow fade to black”) or a much more violent Big Rip, where “our planet explodes … molecules crack open … black holes are eviscerated. And at the final instant, the fabric of space itself is ripped apart.” In the chapter on Vacuum Decay, Mack explains the recent discovery of the Higgs Boson and the Higgs field that underlies the theory and how theory also says that it carries with it the potential to create a “bubble of true vacuum [with] a drastically different kind of space … that could incinerate everything it touches … total and complete dissociation.” In one of the quirkier aspects Mack presents in the book, nothing in the theory prevents this from already having happened, so as far as we know this Bubble of Certain Annihilation!! (as Marvel comics might put it) is already slowly heading our way.
Continuing in her exploration of very recent discoveries, gravitational waves (just observed in the past two years) are an important player in the “Big Bounce” theory, whereby we live in one of multiple “branes” that slowly have been drifting apart but will eventually come together again to unleash another Big Bang (unfortunately, wiping us out in the process).
The science throughout The End of Everything (Astrophysically Speaking) is explained clearly in easy to follow fashion, with a good number of helpful illustrations. Mack handles the science deftly whether she’s zooming in or taking a broad view, and she is careful to not overhype discoveries or present theories as overly definitive. One of my favorite moments is when she writes:
…the original version of inflation is widely considered to be a stroke of genius in spite of being in the end a total failure. It didn’t work at all, and was totally revamped by other physicists within about a year. What its originators did exactly right was to propose a general class of solutions that became the spark of a firestorm of creative ways to finally make the Big Bang work.
This is a view of science too often lacking in news accounts. How science builds more on “failure” than success (and thus failure is never really failure), how science doesn’t worry about getting things “right” because being “wrong” is just a step in the process, and how science rarely is a single person’s “discovery” but is a much more collaborative effort.
Personally, I wanted a bit more detail and more complex science, but while I’m not a scientist I read a lot in various fields, so someone coming to this as a first or early dip into popular science will probably find this at the perfect level. Also, the footnotes offer a little additional detail for those looking for more, as well as some lighter or more digressive bits. With regard to tone and style, Mack is engaging throughout, offering just the right amount of personal experience and opinion as well as a decent amount of soft humor that neither distracts nor detracts from the reading experience. And while forays into the lyrical are rare, they’re effective enough that Mack should consider doing more such in her next book. Which I’ll be happy to pick up based on The End of Everything (Astrophysically Speaking).