The Quantum Universe: Everything that can happen does happen [Hardcover]

This isn't a safe book. It isn't one of those well crafted yet bland and simplified introductions to quantum physics, the type that breeze you on through the history and development of our realisations. Don't get me wrong - those are good books, many of which would complement and round out this latest offering from Cox and Forshaw. Instead, this is a book to make you think for yourself and wrestle down those fleeting shadows of insight as they flit past our consciousness, until, as if we were making the discoveries with them anew, we have our own little "Eureka" moments.

Starting from the most basic of principles and following the simplest and, one might say, obvious rules, Cox and Forshaw use a novel conceptual technique to lead us from the microcosmic world of the quantum into discovering why the macro world is as it is. More than that, we are left realising that it is not the quantum world that behaves strangely at all, but that the world as we know it is an amazing and yet inevitable realisation of the counter-intuitive behaviour of the quantum world.

The discovery and realisation of just why a particle-like nature appears out from a wave function is then surpassed by the insight into the limitations of quantum fluctuations and the revelation of how "real movement" occurs. The same conceptual technique shows why quantum behaviour is "fuzzy" and how, without resorting to macro-view analogies, the Heisenberg Uncertainty Principle is built in to the fabric of the universe.

Frankly, had they stopped there I would have had my monies worth. But they then go on to demonstrate how these insights must truly be present in the quantum world in order for our modern discoveries and technological developments to work.

In a final act of exuberance, Cox and Forshaw pose their own version of an Einsteinian thought experiment... taking some basic axioms from physics and the nature of quantum behaviour to demonstrate how it is possible to calculate the maximum mass of a dead star. Yes, this section is a delve into the world of equations (though rather more engineering than physics!), but you have to forgive them revealing their passion and revelling in the beauty of such a demonstration.

I would not give this book to my mother for Christmas. But it will appeal to anyone with a passion to discover how the physical world works. It will challenge you to think for yourself and reward you as "the penny drops". I wish that I had read it when I was fifteen years old... what an inspiration that would have been!

Most of the reviews I've seen for this book seem to be either from scientists who 'get it' or laymen who do not. All I can say is that I don't come from a scientific background, having found it all rather baffling at school but have become more interested in the subject later in life. This is the first book I've read on Quantum Theory & thanks to the clear explanations provided by Forshaw & Cox (AKA 'him out of D:REAM / off the telly with the haircut & telescope'), I both understood & enjoyed it. But then of course, there's the maxim about Quantum Theory that 'if you think you understand it, then you probably don't...'

Cox & Forshaw present this intimidating subject in a clear & reassuring way. There are areas where mathematical formulae are used but they reassure their readers that we shouldn't worry, that they are merely there for people who understand them & for the rest of us, the main points will be explained in the text. So while I found them intimidating at first glance, the authors' excellent breakdowns made them understandable while giving me a deeper appreciation of why mathematics is so important to Physics.

While the authors explain it very clearly, there's no hiding from the fact that this is a pretty mind-bending subject. Cox & Forshaw believe that the difficulty most people have is in assuming that what they call 'small things' must conform to the same rules as 'big things', such as only ever being in one place at once; apparently they do not, instead behaving in a accordance with a totally unique & much less concrete set of rules. So anyone expecting to be able to have a relaxing, passive read & come out of it understanding how a single electron can behave like an entire wave will find their expectations scuppered.

The subject does require effort & those of us who struggle may be reassured to know that we're in auspicious company - Quantum Theory is apparently so unlike the deterministic approach to Physics which preceded it that its pioneers were relatively young & the 'old guard' scientists (including Einstein) found it singularly baffling. But as the authors point out, it's not so much that Quantum Theory is weird, it's more that our 'common-sense' notions of how the world works are pretty bizarre when you take a close look at what's really going on. To this end, the authors address the issue of why we can't actually walk through walls (as actually attempted by the real-life Men Who Stare at Goats). Not only is this an entertaining notion but it also illustrates how unconventional quantum thinking has to be - because what initially sounds like a question too absurd to be worthy of consideration becomes much more puzzling when we consider that the atoms which make up ourselves & the wall consist almost entirely of 'empty' space.

So as long as you can push your preconceptions aside & embrace some pretty challenging ideas, then this is a fascinating read. Not only is it as clear an explanation as you're likely to encounter but the authors' sheer enthusiasm for the subject is utterly contagious. If nothing else, this is an awe-inspiring summary of how utterly clever primates clinging to a rock in the middle of nowhere can be.

Any review of this book probably needs to be prefaced with a declaration of the reviewer's academic credentials, so I have to declare up front 'A' level physics and a PhD in mathematics. I think this is relevant rather than a misguided attempt at trumpet blowing because one's familiarity with certain concepts inevitably colours judgement of a book that does to some part attempt to engage the reader with the nuts and bolts of a difficult subject rather than resort entirely to hand waving and analogy.

Factual matters first; this is a short (200 pages) book whose mission is to provide a reader not versed in mathematics or physics beyond GCSE level (or less) an insight into the behaviour of the universe at the level of the very small. There are difficult but rather beautiful concepts here, and the authors are attempting to convey the essence of those concepts in a way that requires some effort on the part of the reader; clearly a detailed mathematical approach is going to leave all but a small percentage of people lost, but in order to talk sensibly about the subject at all does at least require some acknowledgement of the underlying maths.

As one of the core concepts that needs to be addressed in discussing quantum mechanics is that of complex numbers and Hilbert spaces, the authors have opted to represent this using the notion of one-handed clocks. This is where I can only guess as to whether someone who has never dealt with complex numbers will find this approach more or less confusing than the underlying maths; with my background I found that I was constantly translating the clock concept in my head to try and understand what the authors were actually getting at. Personally I would have preferred a more direct approach; e.g. define a complex number, explain how they are added and multiplied and then use that, but I can understand I'm probably in the minority here.

Overall I found the book very interesting; what I particularly admired was that the authors provided a real insight into why the seemingly bizarre concepts of quantum mechanics can not only explain behaviour at the micro level, but also how those concepts "smooth out" into the more familiar behaviour of objects at our scale (e.g. why we "don't fall through the floor" if the vast proportion of any atom is "empty space").

Full marks to the final chapter too, where the authors do a little bit of mathematics and mathematical reasoning to derive the maximum mass of a star than will not form a black hole. For those that can stick with it, this gives a genuine taste of what it feels like to embark upon a proper 'proof' of something.

I also find the concept of a book that really challenges a lay readership to deal with something unfamiliar and difficult to be very refreshing. Too much information (scientific, political, financial etc.) is presented with a lowest common denominator
approach, treating you as someone too stupid to deal with anything but the simplest concepts. This book, and The Road To Reality: A Complete Guide to the Laws of the Universe are honourable attempts at countering that.