Russell - ABC of Relativity

It is surely an outstanding tribute to Russells extraordinary expository and literary powers that a non-mathematical introduction written over seventy years ago to a major and at that time quite revolutionary physical theory should still provide an accurate guide to that theory. It is also a rather sobering reflection that this excellent book contrasts so clearly in style and presentation with the breathless and sensational writing which so often characterises attempts to popularise science today. Any reader of Russells book, ignoramus or cognoscenti, will be delighted by the good humour, the pellucid and witty prose style of the work and will gain a thorough understanding of the basic physical principles at the heart of relativity theory. As a non-mathematical introduction it is just as valuable now as it was when it was first published in 1925.

Russell remarks in his autobiography (The Autobiography of Bertrand Russell, Volume II, 19141944, London: Allen & Unwin, 1968, p. 152), that he wrote it, its sister volume The ABC of Atoms (London: Kegan Paul, 1923) and What I Believe (London: Kegan Paul, 1925) in order to earn money. Whereas the second of these volumes has been overtaken by the developments in quantum physics in particular the elaboration of the New Quantum theory after 1925 the former exposition has very much withstood the test of time, despite the very considerable advances in relativity and cosmology.

Russell had returned from China in September of 1921 and had no academic appointment. He reports that he did relatively well with his ABC books but remained rather poor until the publication of a book on education in 1926, after which he prospered financially. It is worth nothing what a phenomenal output of writing he managed in the decade from 1920. This included three important contributions to logic and philosophy, a new edition of Principia Mathematica in 1925 and two major works, The Analysis of Mind (London: Allen & Unwin, 1921) and The Analysis of Matter (London: Kegan Paul, Trench, Trubner & Co., 1927). Part of this latter volume formed the Tarner Lectures given in Trinity College Cambridge in 1926. The lectures were devoted to the epistemology of the new physics and contained an elegant, logical and structural analysis of relativity theory and its relation to pure and applied geometry and two lectures on the foundations of the quantum theory as then understood. On top of all this were books on such diverse subjects as China, happiness, marriage and the future of society and science.

This was clearly a period in which Russells thought was dominated by social themes and the need to spread and popularise knowledge in a way which would overcome what he saw as deep-seated irrationality, born of ignorance and lack of educational opportunity, which had manifested itself in the alacrity with which the populations of Europe had partaken in the rise of nationalism and the First World War. It was certainly a heroic period in Russells life, when he earnestly believed that the sort of blind unthinking prejudice which he conceived to be fundamentally responsible for the horrors of the First World War could be transcended by the dissemination of knowledge and the exercise of critical reasoning power by all classes of society. His huge output of this period was designed to bring within, as far as possible, everyones grasp the freedom of thought and action which knowledge and learning brings. That spirit of enlightenment certainly pervades the ABC of Relativity.

There is no doubt at all that Russells book is an expository masterpiece. There are two aspects of it, however, which might mislead the unwary reader. The first concerns what Special Relativity is fundamentally about what its domain of discourse is and the second concerns the transition from the Special to the General Theory. Throughout his discussion of the Special Theory Russell refers to the observer and treats the difference between the classical Newtonian framework and Special Theory as showing that the key relations of simultaneity, length, time and temporal order, which are treated as absolutes in the classical framework, are in the Special Theory dependent on the observer.