The reason we don't receive light from the edge of the observable universe is simple. The Doppler Effect causes the light to be red shifted to a frequency of zero. Well, that is what we say. I better qualify that a little bit. The stretching of space due to the continued expansion of space causes the wavelength to be so long that it is undetectable.

Bill Gill

C is not the speed of light in a vacuum.
C is the universal speed limit.