Epicycles were brilliant math, as a model of our geocentric view of the cosmos. The crystalline spheres were lousy physics, as explanation.

How much should we trust our current mathematical models?

Consider that when they realized cosmic redshift increases proportional to distance in all directions, it either meant that we are at the exact center of the expanding universe, or this galactic redshift was an optical effect. Given the light was otherwise clear, it didn't seem any medium was impeding it, so it was decided that Einstein's "spacetime," the physical explanation for the Math of Relativity, meant that space itself could be expanding. Thus every point would appear as the center.

What seems to be overlooked, if not ignored, is the basis of spacetime is the speed of light and how to explain it as a Constant, in any frame. Such that in a moving frame, both time and space are dilated equally.

Meaning that if space were to actually expand, the speed of light would have to increase, in order to remain Constant!

Yet what they mange to do, is extract two metrics from the same light. One based on the speed and one based on the spectrum.

If the speed were being used as the numerator, it would be a "tired light" theory, but as an "expanding space" theory, the speed of light is still the explicit denominator. The metric by which this expansion is being measured. Einstein's proverbial ruler; "Space is what you measure with a ruler."

So are we really as accomplished as we assume, or is it more stories we tell ourselves?

https://www.americanscientist.org/article/modern-cosmology-science-or-folktale