Antimatter

[sawyl]

Having misplaced my copy of The Human Touch, I took Nick Lezard's positive comments about Frank Close's Antimatter as a hint from providence.

The goal of the book is obvious from the outset: to provide an accessible refutation of many of the crank claims that surround the idea of antimatter. It does this by describing some of the more absurd claims — that antimatter was responsible for the Tunguska event; that the US military is in the process of weaponising it; that Dan Brown's Angels and Demons should be read as fact — and then setting out enough high energy physics to knock these claims down.

Starting from nothing, the first few chapters establish basic descriptions of atoms, of the link between energy and matter, how the two possible solutions to the Dirac equation provide a theoretical basis for antiparticles, and how, subsequent to Dirac's work, antiparticles traces were discovered in cloud chambers. This then leads on to the idea of bosons and fermions, how powerful new particle accelerators led to the discovery of the discovery of new particles, and how antiparticles are created and stored.

The book then briefly delves into CPT theory, in order to describe the problem of kaon oscillation and, amusingly, how this might be used to determine whether an alien world (full of intelligent aliens!) is made of matter or antimatter. This is combined with the idea of an inbalance between K and anti-K decay to suggest a reason why, post-big bang, matter exists in bulk while antimatter does not.

With all this established, Close returns to his opening theme. He shows why the Tunguska event is not consistent with an antimatter detonation and provides a more plausible explanation based on a chemical detonation. He then explains why antimatter is unlikely to be of much use as a fuel, given the energy costs of creating the stuff, or in a bomb.

But in pride of place in the last chapter is granted to Dan Brown's Angels and Demons. Brown is clearly a real source of irritation because Close devotes the final pages to pointing out a number of factual errors in the book, including the sloppy historical details, the uncertainty over the natural of the antimatter involved in the bomb, and the idea that it is the perfect weapon because it creates no pollution — something Brown himself contradicts a few pages later...

So, in summary, I really rather enjoyed Antimatter, although it turned out that I was already familiar with much of the science — I was surprised by how much of the theory, probably picked up back when I was a Real Scientist, came crawling out of the back of my brain when prompted — the history and the engineering were new and, besides, I more than needed a refresher on the details. And the details were excellent: Close is admirably clear, his examples are well chosen, the book isn't too heavy on maths — the details of Dirac's work are included in a brief appendix — and the whole book is extremely concise and readable.