dehammer asks:
"if they have no way of measuring the movement separately, its sounds like an opinion. tell me how is it that our galaxy and Andromeda's are approaching each other unless there is a contraction of space"
I already answered that earlier in this thread but apparently you didn't understand it. Reread my comments about GRAVITATIONALLY BOUND objects. And then reread the links I provided for the same content.
The local group of galaxies are gravitationally bound. That means that their common gravity is strong enough to overcome the expansion of spacetime.
BTW We are closing with the Andromeda galaxy at the rate of more than 670,000 miler per hour. Whereas the Virgo cluster is being carried away from us at 2.370.000 miler per hour and the Coma cluster at 16,000,000 miler per hour.
Source:
Astronomy Magazine
September, 2006
Pages 58-59
