From my other post, referencing the relationship between the expanding space of the universe;

"Based on our estimates on the rate of expansion: the sources of light (that were only 22 million light years away from us 13 billion years ago) are now 46 billion light years away."

Notice that light speed is the metric being used to measure this expansion, going from 22 million lightyears to 46 billion. Yet the actual light crossing this expanding space took 13 billion.

In simple, basic, mathematical terms, light speed is the denominator, the distance being measured is the numerator.

Which gets us back to the original problem, since there is being assumed this stable measure of space, aka, light speed, the Ruler, in Einstein's terms, it would seem to be basic doppler effect and we back at the exact center of the universe, or it's an optical effect.

Otherwise, if "space" is expanding, what is light speed measuring, as the metric, the Ruler, if not the "space?"