| Astrophysics (Index) | About |
The term cosmological distance generally means a distance covering a substantial part of the observable universe, such as a gigaparsec or more. The term suggests sufficient distance that there are differences in the universe (e.g., regarding star formation and galaxy formation), that observing over the distance is affected by redshift and cosmological time dilation, and potentially by curvature and a varying Hubble parameter, and limits the usable methods for studying astronomical objects such as galaxies.
The specific term cosmological distance ladder refers to the combination of distance measurement techniques used to measure cosmological distances.