SCIENCE RULES THE WAVES

Evening Star, Issue 19722, 24 November 1927, Page 12

SCIENCE RULES THE WAVES

MASTERY OVER THE LIGHTNIHS

From the earliest days of lininan intercourse all communications between individuals has been attained, perlorce, through the medium of wave motion, by .sound waves travelling through air at IjlOUft per second to convey the inflections of speech to the nerves ol the ear, and by light waves Hashing at the rate of 180,000 miles per second through the other of space to boar the images of primitive gesture to the sensitive nerve endings in the retina of the eye, there to bo the source ol stimuli which arc passed by means as yet unknown along the nerves lo the brain cells, and interpreted by the still mysterious processes of intelligence. Until quite recent times no great advance in communications bad been made. Beacon liras might Hash a message from liillto? to hilltop, a speedier transport could convey the speaker or his written word-more readily to the audience, steam came lo replace the muscles of man or horse, and news of battle no longer waited for the passage of Phcidippidcs. And then with drama tic suddenness came a gigantic leap forward, when man gained mastery over the lightning, for one of the greatest gilts of electricity to the modern world is tho way in which it has facilitated human intercourse, has made the world so much smaller (writes “F. 1.8.,” in the ‘Age’). First came the telegraph and Mio submarine cable, and then the wireless wave, and man’s communications—first in codo and then the spoken—attained the speed of light itself, so that when television conics to bo lully .established any man will be able to bo present visibly and audibly to any other man upon* the earth in’the fifteenth part of a .second.

Tliis tremendous advance in human relations has come about in a few short years from the investigation of the waves which flow through the ocean of ether, and no one can prophesy what wonders a further study of them may yet reveal. It is the emission of electrons by vibrating atoms in the filament of the iicrmionic valve' which has made possible the progress of radio, and the latest work of American physicians is leading to the conclusion that electrons themselves arc waves, and must not bo conceived of as being in any sense material particles. Just as these atomic vibrations may be used to generate and amplify the ether waves, which have given us a power of thought transmission from distances, and at a speed undreamed of a few years ago, so it must be atomic vibrations of sonic sort in the colls ol the brain which transform the nerve stimuli to conscious thoughts. It has been suggested that thought is itself a vibration, a part of the universal energy of the universe, which might reach out to other minds, eleven to the Supreme Mind itself, on wave lengths unknown as yet, to which other intelligences might be tuned. These vibrations must go on for ever, since like all atomic energy they have almost imperishable force, and since philosophers like Bergson have postulated, and Einstein seems to have proved, that time is one of the dimensions of space, and must bo taken into account in relations of space ’between” moving bodies, wo may yet secure a “ time'machine ” to enable ns to tuuo in oneo again to the thoughts of a bygone lender or to live anew the emotions of the past. The ether waves which are made use of in radio occupy but a fraction of the wave band which is known to us, extending as they do from 20,000 or so down to about five metres in wave length. Within these limits there aro considerable differences in the properties of the vibrations, and wireless amateurs have shown, for instance, that a wave length which is suitable for long*, distance daylight transmission is oltcn not effective during the hours of darkness. Of waves whoso wave length, is loss than a metre or so we know little,'and hero there is a wide Held for investigation’for the future. Wo come next to tho infra-red rays on the fringe of the light spectrum., the term rays being commonly applied to waves of very short wave length.

These rays accompany the transmission of energy by the radiation of heat, and, altliougli they arc invisible lo the human eye. the English scientist Baird has .shown that by their aid objects in complete darkness may bo rendered visible through the medium' of his television apparatus, whoso sensitive screen is effected by these rays just as by visible light. They penetrate fog as well as darkness, and appear to have many applications in the future in navigation and in war. .The visible rays of the light spectrum, the wave lengths to which the retina of our eye is turned, and which blend together to give the sensation of white light, range approximately from 65’millionths of a centimetre for red to 40 millionths of a centimetre for violet and within these limits are comprised all that our eyes can toll us of the beauty of the world around us, the color of llowers and of sunsets, dawn on the mountains, and white-capped waves on the sea. It is the shorter light waves, those at the violet end of the spectrum, which are capable of producing chemical changes such as their effect on the salts of .silver which makes possible the art of photography and tho existence of Hollywood. Those of a shorter wave length still flic ultra-violet rays, are now known to have a curative influence in many forms of tuberculosis, and are almost specific in the case of infantile rickets. . New formuho have been developed for glass which is permeable to the ultra-violet rays, which are absorbed by ordinary glass, and windows aro nowavailable for hospitals, schools, and homes which allow tho full beneficial effect of sunlight to stream through, while mercury vapor lamps create an artificial sunlight rich in these lifegiving rays when Nature’s luminary' is obscured. It is the ultra-violet rajs which give rise to vitamins by their action on crgosterol, a. constituent of many fats and oils, and which are stored in green foodstuffs by the action of sunlight. Tho vitamins in which cod liver oil is so rich come c ’ginally from the plankton, or minute plantlike organisms which absorb the sunlight on the surface of the sea, whilst cows which receive green food give butter rich in these “accessory food factors.” while those which are fed on roots and. kept hr, roomy sheds away from tho sunlight secrete no vitamins at all in their milk. Of shorter wave length still are X-rays and cathode rays produced by the bombardment of atoms by electrons, ami finally tho cosmic rays, recently discovered by Professor Millikan, have the shortest wave length of any rays yet discovered. These very penetrating radiations, which are believed to bo generated by atomic charges enormously more intense than any radio-active processes yet observed. arc received from all directions, and are considered in all probability to emanate from some of the great spiral nelmhe. But this review of the waves which How in the ether must end upon a query, for of the properties of those cosmic rays and of their possible in--11 lienee upon tho earth or upon jiving organisms wons yet know nothing.