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> Is it more accurate to interpret inferred distances derived from redshift as an average estimate? We don't estimate distances just based on redshift. We use
by pdonis 4y ago
> Is it more accurate to interpret inferred distances derived from redshift as an average estimate?
We don't estimate distances just based on redshift. We use all three of the observables I mentioned--redshift, apparent luminosity, and angular size--as inputs to estimate parameters in our cosmological models, and one of those parameters is the scale factor--the "size" of the universe, which is what is used in the model to ultimately get actual distances--as a function of time. The models of course have error bars--no model is ever exact--and some of those error bars are due to variations of the motions of individual galaxies from the idealized cosmological expansion in the models. So in that sense distances given by the models are a sort of estimate, yes, based on the average motion.