In Search of Schrödinger's Cat, by John Gribbin

In Search of Schrödinger's Cat is a beginner-friendly introduction to the world of quantum physics. It guides the reader through discoveries of seemingly-unrelated phenomena and builds up to the groundbreaking quantum-specific discoveries gradually.

A lot of the book is really approachable, as it's meant to be, and some of it is really quite unintuitive and hard to get a grasp on. The author acknowledges it, but can only bridge the gap so far - after all, quantum phenomena are so interesting because they defy the classical understandings of physics that we have.

It doesn't help that a lot of what we know about the quantum world isn't well-understood. As Feynman once said, "If you cannot explain something in simple terms, you don't understand it.". Many of the discoveries made in the quantum realm were made by young scientists with a newfound intuition on how small particles might behave and then ran experiments to validate or invalidate the behavior they predicted. Some of the scientists even did some dirty mathematical tricks to make some of the math work out, like cancelling out two distinct infinite terms (but nobody cared because experiments backed it up).

Practical applications of these dodgy mathematics are everywhere, though. Transistors function in the realm of quantum physics, for example. Our very sun's behavior can only be explained through our understanding of quantum physics. Quantum computing services are now available through the internet, though applications are limited. I can't bring remaining examples to mind right now, we owe a lot to these sketchy equations.

The fun parts come in when the author abandons the portions of quantum theory that are provable and moves into the realm of science-fiction fodder; maybe the universe splits in half every time we record the path of an electron, or perhaps the entire universe is a single particle moving through spacetime.