The Universe of Light

Abstract

WE can, in England, look back on a long list of eminent men of science who, so far from disdaining any attempt to popularise knowledge, have spared no pains to bring home the truths of science to the layman; and the layman has not been inappreciative of these efforts. A series of some half a dozen volumes clothed in red the Manchester science lectures for the people tells eloquently of the. crowds who thronged to the Hulme Town Hall to hear Roscoe, Clifford, Rucker, Thorpe, Huxley and a score of other famous Victorians elucidate the scientific problems of the time in a way which may seem over-serious to the lighter hearts of to-day, but which, if numbers be any test, was admirably suited to the needs of their hearers. These lectures, born of Roscoe's energy and drive, were a dominating feature in the life of Manchester in the early 'seventies of the last century. In London, Faraday had not long gone from the Royal Institution, Tyndall was at the zenith of his fame, and was irritating the Scots school of physicists by his solemn championship of Mayer. The persistence of force was a phrase still heard; the specific heat of electricity had still some elements of novelty; and the “Descent of Man” was a best-seller. It is all very interesting, and very crinoline-ish; and it is something of a surprise to realise that Boyd Dawkins, doyen of that far away group of Manchester lecturers of the 'seventies, was taking an active part in a British Association meeting some six years ago. Manchester and London were then two foci of scientific learning. So they are to-day, and we of the nineteen thirties are specially privileged in being able to hear Sir William Bragg's almost magically easy unravelling of the complexities of modern optical science. It was all very well, sixty years since, to explore the field of spectrum analysis, or to argue the question of the formula of water; the expositor of to-day, faced with an array of photons, neutrons, diplons and positrons, has a different and difficult row to hoe. Sir William accomplishes the feat in a characteristically genial and effortless manner, clinching his appeal to theory by admirably conceived experiments, and stimulating the interest of his hearers (and readers) by illustrations?the laws of perspective, Japanese mirrors, rearlight reflectors, the lustre of sateen, and so forth?which keep us constantly in touch with reality. Ars est celare artem; and, as with BoswelPs report of the famous dinner episode, it seems very easy until one tries to do it for one's self.

The Universe of Light.

By Sir William Bragg. Pp. xi + 283 + 26 plates. (London: G. Bell and Sons, Ltd., 1933.) 12s. 6d. net.