Glancing at the reviews for Brian Greene's overview of how we view the stuff of which our universe is made, it seems that some people base their rating and opinion on how much they agree with the science, or how credible they find it. While I have read a fair few popular science books – especially in the areas of physics and cosmology, areas I find utterly fascinating and about which I am perplexed that anyone can not be astounded and beguiled – I have to assume that I am reading a fair explanation of facts and theories. That is not to say that I assume the author is more knowledgeable than me simply because he has more letters after his name, but because he grounds his claims with background and the weight of evidence that is needed for a scientific hypothesis to become a generally accepted theory. Also, I have taken the effort to educate myself in these areas so have enough grounding myself to be able to appreciate the arguments.
That said, for much of this book I'm unsure how much background would be needed to understand the explanations. Greene writes with a clarity and readability which is all too rare in any field, and is particularly welcome in discussing such big ideas. As in Stephen Hawking's The Grand Design, Greene completely dispenses with calculations but, unlike Hawking, he also tries to keep the use of metaphor to a minimum. It cannot, of course, be dispensed with – metaphors are an extraordinarily powerful descriptive tool, especially in a field that can only properly be explained and understood using specialist mathematics – but for the most part Greene simply gives an overview of each field in historical context, and explains WHY it is important, what it explains and why it works.
He starts – as modern physics in so many fields must – with Isaac Newton, and particularly Newton's Bucket. If you hang a bucket of water on a rope and twist the rope, as the rope unwinds, spinning the bucket, at first the water remains stationary until the friction of the bucket's movement makes the water begin to spin. When it does, the surface becomes increasingly concave, moved outward by what why now call centripetal (or centrifugal) force. But what, asked Newton, is the water moving away from, or toward? What is it moving in relation to? He decided that it moved in relation to the fixed fabric of the cosmos, the stuff in which the matter (that he recognised as being the thing on which gravity works) sits. Recognising that he had no way of testing this medium by experiment, Newton took this is an immutable absolute and left it at that. Greene keeps returning to the bucket and its implications throughout the book, to superb explanatory effect.
I won't go further into the details (read the book!), but simply say that thanks to Professor Greene I now understand areas of cosmology and physics where I had previously had to simply give in to brain cramp and accept as being true. I understand why the speed of light (actually, the speed of any electromagnetic radiation) is approx 300, 000 km/sec faster than you, no matter how fast you are travelling. I understand a whole lot more about General Relativity and Quantum Mechanics, and why they make sense and are such powerful tools in describing our universe. I understand that Inflationary Theory is not merely a tweak of Big Bang theory to enable it to fit observed facts, but a whole new way of looking at the growth of the universe that actually explains much more about the fundamental physics.
I'm not claiming a thorough understanding of these subjects (and in some, like Brane Theory, I still found myself rather lost; a re-read may be in order), but I feel that The Fabric of the Cosmos has deepened my comprehension of and appreciation for the wonders of our universe. And for the wonders of the human mind to work out these things. In around three hundred years we have developed this system, science, as a means of examining the world around us in a way which is comprehensible to anyone who is willing to put in the work. All books on science now seem to feel the need to restate this about science; it is NOT knowledge passed down from on high by men in white coats using deliberately obfuscatory language for reasons of either professional pride or conspiracy. Science is a method that enables us to understand more and more about the world, to revel in the joy of knowing how the rainbow is formed as well as in its simple beauty. No idea in science is sacrosanct, no theory is holy. To achieve the status of acceptance of say, General Relativity or Evolution by Natural Selection, a theory has to be tested – that is, it has to survive again and again and again the onslaught of people systematically trying to prove it wrong. When a weakness is found the theory must be re-examined. Sometimes the fault will cause the foundations of the theory to crumble, and it will be discarded; it has still served a purpose, to show how promising such an approach is. Sometimes finding the errors will strengthen a theory and teach us more – Edwin Hubble's original calculations of distant galaxies seemed to show the universe to be about 1.5 billion years old, despite lots of other evidence at the time insisting it was at least 3 billion years old (as we now know, this was still almost five times too conservative). Everything else about Hubble's observation and theory made sense, there was simply an error in calculating the distance of the super novae he was using to get the figures, a correction which itself taught us much about the universe.
And this is incredibly important to realise because, while many theories, however much work they take, partly make sense on an intuitive level you get to Quantum and Brane theory and they simply cannot – in fact they seem, by intuition and everyday experience, utterly ridiculous (the great physicist Nils Bor said something along the lines of “if you think you understand Quantum Theory, you don't understand Quantum Theory”) but they are undoubtedly right. One important way a theory is tested is to use it to make predictions in the physical world and Quantum Theory has been called far and away the most successful predictive theory in science. It is, like every successful theory, one that accurately describes the way our universe works, with the limits of perception and understanding we have, which is why theories are modified or discarded when new information comes along. Which is why General Relativity replaced Newton's Laws of Gravitation as the best description we have for how gravity works – although NASA still use Newton's calculations most of the time, for the same reason you don't need to understand Gaussian Quadratic Maths to balance your chequebook.
Greene's book, the first I've read by him, shows why it is worth reading a range of books on the same (or closely connected) areas of science. While in The Grand Design, Hawking and Mlodinov managed to convey a sense of wonder and discovery on a par with Carl Sagan's writings (a plaudit I don't throw around lightly!), Greene has given us a book that manages a clarity and depth of explanation while being a thoroughly entertaining read. At schools, perhaps instead of training our children into narrowly defined roles, science classes should just be introducing them to the works of Greene and Hawking, Sagan and Tyson (Neil deGrasse, not Mike) and Krauss to show them how huge and wonderful and beautiful the universe is, and how much joy and fulfilment can be achieved through our efforts to understand it.