On the Definition of Distance in Curved Space, and the Displacement of the Spectral Lines of Distant Sources

@article{Whittaker1931OnTD,
title={On the Definition of Distance in Curved Space, and the Displacement of the Spectral Lines of Distant Sources},
author={Edmund Taylor Whittaker},
journal={Proceedings of The Royal Society A: Mathematical, Physical and Engineering Sciences},
year={1931},
volume={133},
pages={93-105}
}

Proceedings of The Royal Society A: Mathematical, Physical and Engineering Sciences

The displacement of lines in the spectrum of a distant star, on the assumption that space-time is of constant curvature (the “de Sitter world”) has been extensively studied. The question, however, is not yet settled, different investigators reaching conclusions which are not apparently concordant. The origin of some of the discordances may be traced to the ambiguities which are involved in the use of the terms “ time,” “spatial distance” and “velocity,” when applied by an observer to an object… Expand