2
votes
1answer
36 views

Cosmological and gravitational redshift in physics

I am interested in knowing what are the differences between gravitational and cosmological redshifts?
1
vote
3answers
250 views

Redshift of light in dark matter

Following Edwin Hubble, it is widely believed that the universe is expanding, which is based on the red-shift of light from distant objects. Can dark matter cause light to be red-shifted and make it ...
4
votes
6answers
213 views

Why are distant galaxies not actually tiny bits of matter?

Distant galaxies are said to be moving away from the Milky Way (and us) at speeds approaching the speed of light. Since Special Relativity tells us that any object moving away from us at a velocity of ...
0
votes
2answers
252 views

Reformulated: Universe expansion or collapse

I reformulate the question a little bit because I feel that I was misunderstood. There are cosmic observations that tell us the universe seems to expand. It also seems to expand always faster ...
5
votes
2answers
253 views

Expanding universe

If we know the universe is expanding in whatever direction we look, can't we reasonably estimate where the 'center' of the Universe is? Is the rate of expansions in all directions the same?