There is a minor little problem with using the premise of spacetime to say that space expands. Logically the speed of light would have to increase, in order to remain constant.

This theory assumes two metrics of space, derived from the spectrum and the speed of the same light.

As an, "expanding space" theory, the speed is still assumed to be the denominator. Otherwise, if the speed were the numerator, it would be a "tired light" theory.

The basic math is tossed out the window, to make it work. No wonder they keep having to add these enormous patches, inflation, dark matter, dark energy.

Now they keep finding ever further and older galaxies. At what point do they admit the shoe no longer fits?