The Quantum Divide – Christopher C. Gerry & Kimberley M. Bruno ***

Broadly speaking, science books are either popular science or textbooks. The popular science book is aimed at a general audience with little or no science background required and fills in the basics in a far more interesting way than science was every taught at school. The textbook does the business of educating with the theories, while not worrying too much about the historical context, with readability always coming a distant second. It assumes the reader has science and maths education to the required level. But The Quantum Divide, perhaps in keeping with the concept of quantum superposition, manages to be a bit of both at the same time.

What we have here is an exploration of quantum physics and the divide between the world of quantum particles and the macro universe. It is pitched in a way that I have simply never seen before. For a very narrow band of readers this book is absolutely superb. If you have been fascinated by a book on a quantum subject, like my own The God Effect on quantum entanglement, but want to dig into more depth about what is actually going on, and what was really undertaken in some of the experiments you usually have to either read a textbook or go to an academic paper. But both of these are pretty impenetrable and too maths-heavy for the general reader. Gerry and Bruno give that extra meat without requiring heavy duty mathematical support. There are equations in here, but they are used as shorthand, not to do maths. The result is quite extraordinary – it really expands on anything you can get from a popular science book without being too heavy to cope with, and for that, the authors need a huge pat on the back.

To be honest, though, I don’t think most popular science readers actually want this extra detail. On the other hand, university level physics students will find it too basic and not mathematical enough (though it could provide a good introduction before a course). This is a great book for, say, science journalists and those with a similar level of semi-professional interest – but probably not for many others.

The other slight problem is that the authors can occasionally be quite prissy and negative about guess who… science writers. Their audience in all probability. Take this quote:

Quantum theory does not predict that an object can be in two or more places at once. The false notion to the contrary often appears in the popular press, but is due to a naïve interpretation of quantum mechanics.

The problem with this attitude is that it entirely misses the point. All descriptive models of something as counter-intuitive as quantum theory are inevitably approximations – what they are really doing here is not liking someone else’s language, even though it gets the basic point across better than their version. I don’t think this is any more a problem than when physicists speak of the big bang or dark matter as if it they are facts, rather than our current best accepted theories.

There’s a similar cringe-worthy section where the authors attack the suggestion that light is a particle in the true sense, which again seems nit-picking. Their argument seems to make little sense and given Richard Feynman was happy to say ‘I want to emphasize that light does come in this form – particles’ I find their position hard to justify. So there are a couple of places where a particular slant of interpretation gets in the way of what otherwise is excellent explanation – but I think that can be forgiven.

Overall, then, a worthy and fascinating book but one that I suspect will only ever have a very limited audience.

Hardback:  
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Review by Brian Clegg