Thanks.
I wasn't doubting that the speed of light is constant, I actually said I don't yet, meaning that if no one had a reason for it then I would.
Otherwise, it was very helpul. Thank you.
The biggest chunk of evidence for expansion of the universe is the whole red-shift/Doppler effect deal, saying that as something that emits light while traveling away from the observer, the wavelength of the light will be "stretched" making it appear red. There is one thing I'm wondering. Could...