Thursday, 27 October 2011

The Infinity Puzzle – Frank Close ****

This is a really important popular science book if you are interested in physics, because it covers some of the important bits of modern physics that most of us science writers are too afraid to write about. Starting with renormalization in QED, the technique used to get rid of the unwanted infinities that plagued the early versions of the theory and moving on to the weak force, the massive W and Z bosons, the Higgs business and the development of the concept of quarks and some aspects of the theory covering the strong force that holds them in place, it contains a string of revelations that I have never seen covered to any degree in a popular text elsewhere.
Take that renormalization business. I have seen (and written) plenty of passing references to this, but never seen a good explanation of what the problem with infinities was really about, or how the renormalization was achieved and justified. Frank Close does this. Similarly I hadn’t realised that Murray Gell-Mann, the man behind the ‘quark’ name, originally took a similar view to quarks as Planck did to quanta – a mathematical trick to get the right answer that didn’t reflect anything real in terms of the particles involved.
For at least the first half of the book I was determined to give it five stars, despite itself. The content was sufficiently important and infrequently covered to require this. That ‘despite itself’ is because this is no light read – it makes the infamously frequently unfinished Brief History of Time seem a piece of cake. I think the reason for this is that the concepts here are more alien to the reader than those typically met in traditional ‘hard’ topics like relativity or quantum theory. Close does define a term like gauge invariance before using it, but then keeps using it for chapter after chapter. The trouble is, to the author this is an everyday concept, but to the reader the words are practically meaningless (unlike, say space and time in relativity), so a couple of pages on from the definition we’ve forgotten what it means and get horribly lost. These aspects (spontaneous symmetry breaking is another example) would have benefited hugely from a more detailed explanation and then use of more approachable terms along the way rather than what can be a highly opaque jargon.
I could forgive the author this though. After all his writing style is fine and there is all that interesting content. But there were a couple of things that dragged the book down a little for me. The first was a tendency to skip over bits of science, leaving them mysterious. For example, at one point we are told that a process can be split into five categories: scalar, pseudo-scalar, tensor, vector and axial. Of these only vector and scalar are defined (there are brief definitions in the end notes, but nothing in the main text), so when we are told that the weak force was classified as V-A, we have no clue what this means as we don’t know what axial means, or the significance of the minus sign. This is Rutherfordian stamp collecting, giving us labels without understanding the meaning.
Worse though, and the dominant part of the second half of the book, was that there was just far too much dissecting exactly who contributed exactly what little component to the theory, and who got the Nobel prize for what, and who didn’t get it, despite deserving it. Frankly, this is too much of an insider’s idea of what’s important. We don’t really care. I wish this had been omitted, leaving room for more handholding on the theory.
The trouble is, there were far too many people involved to get any successful human interest going in the story. Nobel prizes of themselves don’t make people interesting. I have two scientific heroes in the last 100 years – Richard Feynman and Fred Hoyle. (Obviously I’m in awe of the work of many others – Einstein, say – but this misses the point.) In that same period there must have been getting on for 300 Nobel prize winners in physics alone. I’m interested in their work, but I can’t get too excited about them as people. Those who criticise popular science for being too driven by the stories of a few individuals when so many have contributed miss the point. You can only have so many heroes.
Overall this remain a really important book if you want to get to grips with modern particle physics and quantum field theory. It fills in lots of gaps that other books gloss over. But it would be remiss of me not to also point out my concerns.
Also on Kindle:  
Review by Brian Clegg

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