On the red shift of spectral lines through interstellar space
It is known that very distant nebulae, probably galactic systems like our own, show remarkably high receding velocities whose magnitude increases with the distance. This curious phenomenon promises to provide some important clues for the future development of our cosmological views. It may be of advantage, therefore, to point out some of the principal facts which any cosmological theory will have to account for. Then a brief discussion will be given of different theoretical suggestions related to the above effect. Finally, a new effect of masses upon light will be suggested which is a sort of gravitational analogue of the Compton effect.
© 1929 by the National Academy of Sciences. Communicated August 26, 1929. I wish to thank Dr. ten Bruggencate who kindly set out on the difficult task of testing some of the suggestions presented in this paper.