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Katie Mack: The End of Everything (Astrophysically Speaking) (2021, Scribner) 4 stars

From one of the most dynamic rising stars in astrophysics, an accessible and eye-opening look—in …

Engaging read for general audiences on what we know about the history and future of the universe

5 stars

An engaging read for the general audience about what we currently know about the history and structure of the universe and what that knowledge -- and the pieces we don't know -- might mean for its future and eventual end. Katie Mack writes in a casual, entertaining style. It's clear she finds all of this absolutely fascinating. And she sprinkles the writing with funny stories and quotes and side notes to get across the basics of quantum mechanics, Higgs fields, high-energy physics and the like without delving too much into the math. But the math, and the measurements, are important, because as it turns out, very small changes in how things work at the quantum level can have major implications on the universe's ultimate fate.

The last time I read about this topic in anything resembling depth was about a decade ago. Since then there've been major discoveries in …

Random thoughts:

I've known about the cosmic microwave background radiation for a long time. But I'd always thought of it as "leftover radiation," like a lightbulb fading as it cools down. I hadn't thought of it in terms of looking so far back in time that we're effectively seeing the big bang itself (or at least the point when the universe was still on fire)!

Dark energy as a cosmological constant, something Einstein put in his equations because they wouldn't balance otherwise, then someone else figured out how to get the math to work without it... and then later observations found this weird discrepancy that could be best explained by adding this constant to the equations. Einstein was right even when he was wrong!

I still can't wrap my head around the concept of vacuum decay. It's like an ICE-9 scenario for the laws of physics.

We know more about dark matter than we used to. We can map it. We know roughly how much there is and roughly where. We know what it does. We just don't know what it is yet.

And yet calculations indicate that dark matter and dark energy -- whatever they turn out to be -- make of vastly more of the universe than our own kind of matter!