Pagina 208 de 212

At all events, a definite decision will be reached during the

next few years. If the displacement of spectral lines towards the

red by the gravitational potential does not exist, then the

general theory of relativity will be untenable. On the other

hand, if the cause of the displacement of spectral lines be

definitely traced to the gravitational potential, then the study

of this displacement will furnish us with important information

as to the mass of the heavenly bodies.[27]

[27] The displacement of spectral lines towards the red end of

the spectrum was definitely established by Adams in 1924, by

observations on the dense companion of Sirius, for which the

effect is about thirty times greater than for the Sun.

R.W.L.-translator

APPENDIX IV

THE STRUCTURE OF SPACE ACCORDING TO THE GENERAL THEORY OF

RELATIVITY

(SUPPLEMENTARY TO SECTION XXXII)