The fly in question is the atomic nucleus, which Cathcart tells us was, in the early days of its discovery, compared in size with the whole atom as a fly compares to a cathedral.
This is the story of the race to split the atomic nucleus, not with any application of producing power or bombs in mind, but simply because very little was known about the nucleus, theory needed a lot of help (until quite a way through the book, for example, the neutron was just a crazy idea of Rutherford’s that hardly anyone believed in), and by battering the nucleus into bits more could be found out about it.
It’s terrific stuff. Centred on the Cavendish Laboratory in Cambridge, the main players are John Cockcroft and Ernest Walton, two youngish researchers, with in the very near background the remarkable figure of Rutherford. As we follow the ups and downs of their progress in building bizarre equipment, there’s a terrific feeling of presence – it really is as if you have a view on what was happening. Many other scientists play a role – some, like the remarkable George Gamow coming up with crucial ideas, others challengers to split the atom first.
Part of what surprises is the nature of the challenges. These were still fairly crude pieces of equipment, and one of the hardest things proved to be turning the high voltage electricity used to accelerate the protons used to smash into nuclei from AC to DC – the team had to devise their own rectifiers to cope with the high voltages, initially held together with sealing wax or plasticine modelling clay. Then there is the Frankenstein movie reality of the apparatus. Great glass tubes that glowed, sparks crackling across air gaps, and a lab that was so dangerous that the researchers had to crawl along the ground the observing chamber to avoid being electrocuted.
The author is quite blunt about not having a scientific background, but this really doesn’t stand in the way of his telling a fascinating story superbly well. Perhaps the only surprising omission, that might be explained by this, is that he frequently mentions the British physicist P. A. M. Dirac, and also mentions the US experimental discovery of the positron from early accelerator experiments, but never links the two with Dirac’s earlier prediction of the existence of the positron. However, this has nothing to do with the main story, so is a very minor omission. On the workings of the worlds foremost physics laboratory in the early 1930s this book can’t be faulted, and is a must for anyone who enjoys popular science.