Edwin Hubble

Hubble found the red shift to be proportional to the distance of the star, which led to the conclusion that the universe is expanding. He said that there is a linear relationship between the rate of expansion and the distance. There were disputes on the constant that defines the linear relationship and I read that recently scientists have agreed it to be about 71 km/sec/Mpc.

I have several questions/concerns related to the Hubble's law.

1. WMAP results mention that the expansion of the universe is accelerating. (In fact, I could not find anywhere as to how they have arrived at this conclusion. If any of you are aware of this, please let me know. )If the expansion of the universe is accelerating, the ratio of the expansion to the distance should have a second degree relationship and NOT a linear relationship as defined by Hubble. Either WMAP results are wrong or Hubbles law is wrong. Which one is ?

2. Let us take a Cephoid that is 1 Mpc away from the earth. When we observe the light from this star now, we are looking at the light that left 3.2 million years ago. Basically, when you measure the red shift, you get the 'cumulative' result of the changes in the 3.2 million light years. When it is a cumulative result. .how can it be said that the universe is expanding uniformly in a homogenous manner ?

3. All the red shifts are observed only in the stars in the universe that is 'visible' to us. We have no clue of what is happening beyond the 'visible area' of the universe. Probably, only the area that is visible to us is expanding and the universe beyond that is in contraction !!

I agree with the concept of cosmological red shift, however the above mentioned discrepancies need to be looked into.