Tagged Questions
5
votes
5answers
230 views
How is distance measured to far away stars and galaxies?
What I need is an accurate description of the methods used to determine the distance to Andromeda. The Parallax method is for nearby objects as I presume. The red shift method applies, but how do you ...
1
vote
1answer
475 views
Relation between comoving distance and conformal time?
In cosmology, we have two quantities and I want to understand the physical relation between these two :
$\chi = \int_{t_e}^{t_0}c\frac{dt'}{a(t')}$ : the comoving distance with $t_e$ the time at ...