Goodbye to the Aether
- Wranglers and Physicists: Studies in Cambridge Mathematical Physics in the 19th Century edited by P.M. Harman
Manchester, 261 pp, £27.50, November 1985, ISBN 0 7190 1756 4
Sir Edmund Whittaker’s History of the Theories of Aether and Electricity first appeared in 1910, and is mentioned at the very start of the book under review, though never again. The scope of Whittaker’s book is wide, its material densely organised, but it is a pleasure to read. Whittaker was a stylish writer and a distinguished thinker. Was it really necessary to go over part of this ground again in so much more detail? Unfortunately, there is good reason for doing so, if only because Whittaker did just this when, forty years later at the age of 78, he expanded his original history and added a second volume which was concerned with developments since 1900. The stylishness remains, but the reader’s mind is now alert to the possibility of misrepresentation – the account of the rise of relativity and quantum theory is deeply suspect. There is no suspicion of conscious falsification, rather that the teacher (and he was a great teacher) could not restrain himself from tidying up the arguments. It is with something of a sigh that we retrace the ground in the company of professional historians of science whose prose, it must be regretted, is not always as compelling as Whittaker’s. But their purpose is to tell it as it happened, and even in mathematical physics, whose final expression is so precise, the way truth is attained is by muddle and misconception. One could not believe a tale which unfolded itself too smoothly. I wish, however, that the editor, or one of the authors, had thought to include a critique of Whittaker’s reading of the story they tell, if only as a yardstick for those who will continue to consult him as the only comprehensive historian of a vast and complex phase of scientific thought.
The aim of the contributors is deliberately narrow: ‘the way in which the Mathematical Tripos at Cambridge shaped the physics of men such as William Thomson (later Lord Kelvin) and James Clerk Maxwell’. Of course, nobody believes that even Cambridge in the early years of the last century was so inward-looking that the Tripos and Smith’s Prize examinations were the sole influences on the thought of some of the most imaginative and profound scientists of the time. Nevertheless, they were the instrument by which new ideas might be disseminated, in a way that would be hard to reproduce nowadays. It was perfectly reasonable then for an examiner of Maxwell’s stature to announce a new result by asking the candidates to prove it. After all, only those who aspired to a career in learning, or as coaches for the next generation of wranglers (first-class mathematics graduates), would waste precious time on the arduous pursuit of an otherwise little-valued expertise.
New ways of thought were, indeed, sorely needed, as we can see in retrospect. Newton’s example of a hundred years earlier had been largely unheeded in England, though not entirely in Scotland and Ireland, but had borne fruit on the Continent, especially in France where Lagrange, Laplace, Fourier and many others had developed analytical methods which they applied with great power to problems of natural philosophy. During this period the Royal Society was dominated by Sir Joseph Banks, its president for 40 years, a natural historian who had sailed with Cook and who by temperament was a bigoted anti-mathematician. On the other hand, the empirical study of electricity and magnetism had flourished, and the history of English-speaking investigators from Franklin through Priestley, Michell and Cavendish to Faraday is evidence enough of creative talent applied with uncommon power. Where the Cambridge school of mixed (i.e. applied) mathematics made its mark was in its attempt to marry the qualitative results of the experimenters with the severely deductive mode of French mathematics. Progress was slow but ultimately spectacular, when Maxwell succeeded in formulating the electromagnetic theory which remains the foundation of all subsequent work. Yet the achievement, as frequently happens, left its mark on the victors, who, though still young and capable of great things elsewhere, could not now abandon the conceptual framework which had served them so well. They had to leave the next developments to a new generation of mathematical physicists who were less concerned with logical deduction than with elaborating and testing the consequences of ideas derived from experiment.