Abstracts of Recent Technical Books And Papers From Bell System Sources

Contemporary Physics. KARL K . DARROW. During the twentyfive years since this century began, the science of physics has undergone amazing enlargements and transformations which may well be ranked among the most significant attainments of our times. Through 652 ABSTRACTS OF RECENT TECHNICAL BOOKS 653 discoveries and improvements in the arts of experimentation, it became possible to measure the charge and the mass of the atom of negative electricity; to measure the charges, masses and magnetic moments of the atoms of the chemical elements; to study the processes of detaching atoms of electricity from atoms of m a t t e r ; and to extend the spectra of the elements by detecting a host of radiations previously unknown and determining their frequencies. T h e d a t a so assembled, together with observations upon the encounters of electrified particles with atoms, illuminated the relations between the elements, and contributed to the design of an atom-model which has already inspired m a n y discoveries. Among these the greatest was the discovery of the Stationary States, which replaced the early way of interpreting spectra by a new and strikingly fruitful procedure, and taught experimenters to seek after and find a multitude of new phenomena of the most varied interest and importance in almost every field of physics. To name only two of the fields thus enriched: the flow of electricity through gases, and the conditions for the excitation of radiation, have been clarified in most unexpected fashion since the recognition of the Stationary States.