Friday, January 20, 2006

Book Review: The Fly in the Cathedral

My first piece of scientific reading for the year has been The Fly in the Cathedral, by Brian Cathcart. The book tells how John Cockcroft and Ernest Walton, two researchers at the University of Cambridge, split the atom in 1932. Overall I enjoyed the book, though I got a bit bogged down in the middle with the construction of electrical apparatus - much as the scientists themselves did! It demonstrates clearly the extent to which scientific discovery was (and presumably is) a function of sheer, hard graft. By the late 1920s experimental research on the atom had hit a wall, with very few new discoveries being made. The researchers were stuck, as it seemed the only way to progress in the exploration of the atom would be to bombard it with enormous electrical voltages beyond any that could then be produced. Cockcroft and Walton worked for over three years on designing and refining apparatus capable of firing protons at high voltages. Painstakingly they tinkered with their apparatus, taking it apart and putting it back together, plugging tiny leaks with sealing wax and plasticine, spending hours (or even days) cranking up their machinery to experimental conditions, only to find something wrong. Eventually their hard work was rewarded when their proton accelerator succeeded in splitting lithium atoms into two helium particles. Ironically, it turned out the high voltage they had struggled so hard to achieve wasn't needed after all. They split the atom using only 125,000 volts, rather than the minimum of 700,000 volts physicists imagined would be necessary. Although the book introduces a number of interesting personalities such as the nuclear physics pioneer Lord Rutherford and Russian scientist George Gamow, its main strength is in the insight it gives into the scientific process. A worthwhile read for anyone interested in scientific history in general and nuclear physics in particular.

Aside: One scientific advance mentioned in the book is the discovery of the Van der Graaf generator. I remember absolutely nothing about what we did with a Van de Graaf generator in physics classes, but I do have a memory of a rather uninspiring physics teacher who contrived to give herself not one, but several electric shocks with one in the course of one lesson. Presumably the school version didn't generate a particularly high voltage!

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