Monday, 13 July 2015

The Lightness of Being - Frank Wilczek ****

I need to start this review with two clarifications and a proviso. The first clarification is that this quite an old book (2008), but someone just brought it to my attention. The second clarification is about the book's title. It's not about 'The lightness of being Frank Wilczek', that's just an unfortunate choice of title. The proviso is about the four star rating. This, to me, is a very mixed book. It does two things brilliantly, and quite a lot of other things not very well. If you are interested in modern physics, particularly particle physics and quantum field theory, though, it is a must-read.

Let's get the brilliant things in first. One of the baffling things about physics when you get into quarks and gluons as the constituents of particles like protons and neutrons is that the strong force that holds them together appears to be almost non-existent when the are close, but grows to be extremely strong when they try to separate (and then pretty much disappears a little further apart). As a result of this we've never seen raw, naked quarks, even though the evidence for their existence is good.

The section of the book that covers the theoretical reasoning for the existence of quarks, the experimental evidence we have for them and how this strange topsy-turvey force works the way it does (and, by the way, gives protons and neutrons 95% of their mass - take that, Higgs!) is excellent. It's by far the best explanation I've ever seen. Not entirely surprising when you realise that Frank Wilczek won his Nobel Prize for 'the discovery of asymptotic freedom in the theory of the strong interaction.' And asymptotic freedom is the rather clumsy name (Wilczek apologies for it in the book) for this odd way that the force increases as the quarks try to separate.

The other reason this book is excellent is that it gives a real insight into the kind of mental world modern theoretical physicists occupy. Once Wilczek gets going on what he calls 'the Grid' (because, he says, 'the Matrix' was spoiled as a name by the sequel movies), he is both dazzling and worrying. You might have thought that the ether went out with Maxwell and Einstein, but Wilczek shows how quantum field theorists postulate a whole multilayered collection of ethers filling space, from the assorted quantum fields to strange concepts of universe-filling condensates. I don't know if it's the impression he intended to give, but it really did come across to me as if modern theoretical physicists live in a fantasy world of mathematics which only occasionally touches base with reality when it happens to fit rather well with specific observations. The intention was, I think to show how this viewpoint is inevitable, but instead what comes across to me it that it feels like an abstraction with inevitable parallels with reality but that feels horribly like a house of cards.

Less effective are Wilczek's explanations once he gets away from quarks. I think I understand symmetry, at least to undergraduate physics level, but Wilczek's example that was supposed to show how symmetry worked for beginners totally lost me once he started talking about squeezing the sides of triangles. This, and much of the field theory explanations came across as someone who understood the topic so well that he didn't understand how to explain it to people who don't. It was more like a magician waving his hands at the end of a trick and saying 'So that's how it's done,' without revealing the actual mechanism.

Another slight problem was the writing style which tended to a kind of pompous joviality that I found rather wearing. Here's an example:
So: fully aware of the difficulties but undaunted, heroes of physics gird their loins, apply for grants, buy clusters of computers, solder, program, debug, even think - whatever it takes to wrest answers from the Grid pandemonium.
It's bearable, but hard work sometimes. So a definite recommendation, but with some significant reservations. You have been warned. 

Audio download:  
Review by Brian Clegg

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