THE more or less complete lack of vibrational structure in ultra-violet absorption spectra of polyatomic molecules has made it impossible to locate the frequency corresponding to the pure electronic ...

ALTHOUGH much attention has been devoted to the broadening of spectral lines in the presence of foreign gases, little systematic work has been done on the effect of foreign gases on intensities of ...

To see the various colors that make up starlight, astronomers can use a prism to separate the colors. Common elements like helium and calcium in the atmospheres of stars block certain colors of light, ...