quote:
Originally posted by ramccoid
How can we be sure that all these points of light were conceived at the start of the universe.
We are pretty sure. It's the whole red-shift thing. Doppler shift.
The galaxies are all running away from each other, part of the reason we believe in a Big Bang. The further away they are, the faster they seem to be moving away from us. You can look up Red shift and read details.
So the further away a galaxy is, the faster it is moving, and therefore the redder the light will shift. Calculations can then be made based upon the redness of star light to determine how far away the source is. Analysis of the light from these stars shows two things.
One, it is the type of light that would come from the first generation stars. According to theory, these stars are predominately Hydrogen and Helium, and their final explosions, 10 to 7 billion years ago, are what created the heavier elements we find in the current Universe.
Two, their red light shift corresponds to a galaxy 10 to 7 billion light years away.
The combination of facts convinces us they are 10 to 7 billion light years away.
If they are 10 to 7 billion light years away, their light must have taken 10 to 7 billion years to reach us.
Unless our theories are all wrong.
Explanations for the discrepencies might include:
1) Light travels at different rates in different parts of the Universe.
2) The Universe expands at different rates in different locales.
3) Light and Space were different in the earlier Universe
4) There was more than one center of the Big Bang
5) God did something more marvelous than we yet understand
Etc.