If you look at the sun, it has a spacetime well, with space-tim most contracted at the bottom of the well in the core of the sun. If you look in terms pressure, the material in the core of the sun is packed the most; lowest distances, consistent with contracted distance in the space-time well. However, time goes in the opposite direction, since the core has the fastest frequencies, while time in space-time runs slowest in the core. There are two layer of time.

The reason is gravity is an acceleration, which has the units of d/t/t (one part distance and two parts time) while space time is only d-t (one part distance and one part time). There is time missing from space-time, relative to acceleration.The extra time is connected to pressure and allows frequencies get faster instead of slower.

One needs to think in terms of gravity as two layers, with space-time only one of those two layers. The other layer is connected pressure. Distance in space-time is not invariant as everyone has pointed out. But distance in the extra layer of time, connected to pressure, is invariant and defines specific phases of matter. Specific phases of matter have specific distances, which are the same in all references. In SR, since this uses velocity; d/t, space-time is fully defined. The extra layer of time is not impacted so materials do not change. The younger twin in the paradox does not experience extreme pressure.

If we add the pressure variable, on top of space-time, we can see what appears to be variation in invariant distances, without any phase change. We can see the hydrogen spectra, red shift, such that higher energy levels behave like lower energy levels, but in reality, the hydrogen atom is behaving in an invariant way, in the distant object. The standard hydrogen atom is how we infer motion, since we know this has to remain invariant and any chance is due to SR.

The answer is distance is variant with respect to space-time, but invariant with respect to the extra time (acceleration) connected to pressure. All the force of nature can exert pressure and be impacted by pressure. The extra time connected to pressure is how all the forces/accelerations are integrated, to define a unique summations of forces; characteristic phase.