Clarifying spatial distance measurement
General Relativity and Quantum Cosmology
2022-09-05 v2
Abstract
We examine length measurement in curved spacetime, based on the 1+3-splitting of a local observer frame. This situates extended objects within spacetime, in terms of a given coordinate which serves as an external reference. The radar metric is shown to coincide with the spatial projector, but these only give meaningful results on the observer's 3-space, where they reduce to the metric. Examples from Schwarzschild spacetime are given.
Keywords
Cite
@article{arxiv.1911.07500,
title = {Clarifying spatial distance measurement},
author = {Colin MacLaurin},
journal= {arXiv preprint arXiv:1911.07500},
year = {2022}
}
Comments
6 pages, 0 figures, submitted to the proceedings of the 2018 Marcel Grossmann conference, Rome. v2 has minor rewording and typo corrections