- #1
Tom Mcfarland
- 32
- 2
Several questioners ask if the Hubble red shifts could be gravitational red shifts rather than space-expansion red shifts. I understand why the answer has generally been "no". However, can I try this variation of the question...
Red-shifting is apparent mostly for distant galaxies, which are thus being seen at a much earlier age when the universe (I am assuming) was much smaller than currently. We (the observer) are located at a point which is beyond the part of space which was occupied at the time the red-shifted light began its journey. Thus, the red-shifted light will have needed to rise out of the gravitational potential well of the entire older universe in order to reach our detector today. And the further away the observed galaxy, the smaller the universe was when the light began its journey, and hence the longer this light would need to fight its way through the universe's potential well to reach our detector today...and hence the greater the red shift.
Cheers, Tom McFarland
Red-shifting is apparent mostly for distant galaxies, which are thus being seen at a much earlier age when the universe (I am assuming) was much smaller than currently. We (the observer) are located at a point which is beyond the part of space which was occupied at the time the red-shifted light began its journey. Thus, the red-shifted light will have needed to rise out of the gravitational potential well of the entire older universe in order to reach our detector today. And the further away the observed galaxy, the smaller the universe was when the light began its journey, and hence the longer this light would need to fight its way through the universe's potential well to reach our detector today...and hence the greater the red shift.
Cheers, Tom McFarland