|
How can you differentiate between a doppler red shift and a cosmological red shift or, as distances get further, a combination of the two? Use of standard candles such as type Ia supernovae depends on them performing the same way back into the early Universe. Galaxies can vary enormously in both size and surface brightness and nearby galaxies will have older stars than those further away, so just how reliable is any distance measurement back into the early Universe? Seems like a lot of assumed generalizations.
Regards, Rob.
|