How do we know that light isn't redshifted by space itself?
56753
Is it possible that galaxies' redshift is caused by something else than the expansion of space?
133604
How can we be sure about the constancy of atomic clocks as in the Hafele and Keating time dilation test?
13269
How would we tell antimatter galaxies apart?
4942
What is the relationship between Cosmic Time and Scale Factor (or Redshift)?
12267
(Almost) double light speed
64715
How is it possible that we see light from shortly after the big bang?
128954
How can we see objects that are so far away?
119639
Do photons bend spacetime or not?
143038
As light from a star spreads out and weakens, do gaps form between the photons?
68188
Are scientists missing the point with distant cosmic objects, or is it just me?
62039
What does a sphere moving close to the speed of light look like?
56005
Speed of light travel
145327
Why is "gravitational" red-shift neglected in galaxy and galaxy cluster scales?
68684
Age of the CMB: How do we know?
2154
Why doesn't gravity speed up light?
54193
Can light exist in $2+1$ or $1+1$ spacetime dimensions?
87167
Do cosmological and Doppler redshift produce different patterns?