Physical Conditions in the Stars
The spectrographs have also been used by one member of the staff in the determination of the physical and chemical conditions in stellar atmospheres, a new and difficult problem but one which promises not only very valuable additions to our knowledge of the constitution of the stars but may also lead to economic applications of the greatest importance. A new method depending upon the use of a wedge of dark glass has been applied to determining the distribution of energy in the different parts of the spectrum of the stars and to measuring their temperatures, while an application of the same methods to individual lines may lead to a great increase in our knowledge of conditions in the stars. A special investigation of three of the high temperature O-type stars referred to above has proved the existence in the spectra of these stars of lines predicted as present from purely theoretical conditions but never previously identified and has thus remarkably verified a theory of the structure of the atom. The measurement of the wave lengths of these hitherto unknown lines has led to an important independent determination of the fundamental constants of atomic structure and the dimensions of the atom and has shown that these constants and dimensions are the same in the tremendous furnaces of the stars as in our terrestrial laboratories, a verification of the homogeneity of matter and the uniformity of physical laws throughout the universe. Further interesting results from this investigation are the application of a new theory of ionization with the probable relative abundance of the elements to an independent determination of the temperature of these stars.