(Disclaimer: English is my second language, so I want to apologize in advance for there may be mistakes in the text below. If you find any, please let me know so that I can correct it. I'd really appreciate it. Thanks.)
Review Soundtrack: I suggest reading this review while listening to Superposition by Serosia (YouTube, Spotify).
Reading a book could be considered as a kind of quantum measurement. In fact, until you open the book and read the story, it is in a superposition of "I like it"/"I don't like it" states. Of course, the amplitude of those states might not be equal. You may have prior experience with the author's work or have read (positive or negative) reviews by people with tastes similar to yours and that can make one state more likely than other. But it won't collapse to a definite one until you read it.
In the case of Superposition, by David Walton, I had almost no information to estimate what the probabilities of each state could be for me. I had not read anything written by the author and while the synopsis seemed interesting, involving quantum physics and a murder, it was also a risky combination. Additionally, I had, for some reason, the completely wrong idea that this was a YA novel (it is not) and I hadn't noticed that David Walton was the David Walton that had written Quintessence (which I have not read, but at least knew about). My only chance to collapse the wave function was to read the book and I am glad that I did. Superposition turned out to be, as almost any book out there, a superposition of good and not-so-good things, but the good ones contribute to the combination much more than the others.
The first thing that stands out about the novel is that it is told by means of two parallel plots that occur almost simultaneously, in different places but with the same protagonist. How is that possible? Explaining it would be telling, but it is easy to deduce that the weird properties of quantum particles have something to do with it. In fact, all the science in the novel is based on solid physical principles. Believing that they could occur in the macro-world is, sometimes, a bit of a strain of the suspension of disbelief, but the science is exposed with clear examples and admirable rigorousness. Walton really knows his quantum physics and it shows. Also, and though is not exactly central to the plot, there is some excellent speculation about free will, consciousness and intelligence, and the author makes some really interesting points:
"A dog is conscious, I think," Marek said.
"Or do we just say that, because the dog's programming is more complex, and we can't always predict it?" Brian said. "What about you? I grant you the label of 'conscious' because I ascribe intent and unpredictability to your actions, but when it comes down to it, you're just following your programming, too. 'Consciousness' is just when that programming becomes complex enough to warrant using certain vocabulary."
Another thing that I enjoyed a lot in the novel was the part involving the trial of the main character. Those chapters read a bit like an episode from L.A. Law or Law & Order and are really entertaining. But what I liked the most is how cleverly the author uses them to explore the background of the protagonist, to explain some of the weird science and to create an atmosphere of mystery. And, of course, how the ideas of proof and reasonable doubt in Justice are linked to concepts of quantum mechanics such as uncertainty. Very compelling and thought-provoking work:
The problem with the story was that it was mostly true, but not quite. All considering, I thought it was the best we could do, but it made me wonder how much of the trial system had to do with truth, and how much of it was a competition between the two opposing sides to see whose fiction was the more believable.
The main protagonist is likable, although a bit too perfect for my taste. Some of the secondary characters, however, more than make up for it. I liked Colin and, especially, Alessandra, whose internal conflict made her a very interesting character to read. The prose is not especially brilliant, but it flows very well, making the novel quite easy to follow. The pace is almost perfect, with a good balance between the two subplots and some interesting twists at exactly the right moment. And the mystery kept me interested all way through, which is, of course, one the best things that can be said about a whodunit (quantum or not).
So, as you see, there is plenty to like in Superposition. There is, however, some problems with non-zero amplitude in the quantum superposition that is the novel. Although the resolution is more or less satisfactory, I'd have preferred a not so neat ending. Something a bit more dark, not so family friendly. I had my own theory (that involved not so generous motives from some of the characters; I have my own superposition of perverse and evil thoughts now and then). Also, I find it hard to believe that the people in the novel accepted certain extraordinary and revolutionary facts so easily. They didn't seem to affect the world at large, either, which is really, really improbable when talking about this kind of scientific discoveries.
Despite these issues, the amplitude of the positive elements in Superposition is significantly greater than that of the negative ones, and I recommend reading it if you're looking for an original, intelligent, fast-paced quantum mystery. Supersymmetry, also by David Walton and set in the same world, is coming later this year. I'll probably be collapsing that one too.