You said: We, the solar system, our galaxy, other galaxies are NOT expanding.
How can we know viewed galaxies are not expanding?
The expansion of a galaxy at the distances we are observing them would be indistinguishable.
Even if we observed a galaxy which was twice as large ( as it should be ) we would assume the galaxy is just bigger, not that it expanded.
Only apparent expansions of distances between galaxies would have an observable red shift.
I realize you were refering to the assumptions of an expanding universe "theory".
Theories by definition may or may not be incorrect.
It is necessary to attempt to formulate alternate ideas to determine if another theory is more appropriate
You said: It is much easier to develop a theoretical explanation (there is one) of why galaxies are separating, as opposed to everything shrinking.
Easier is not always better.
I think you may even have a hard time Winning the argument that the expanding universe theory is easier. It does have its problems.
I did not say everything is shrinking - just that our Galaxy is contracting.
The reason I would consider the galaxy is contracting rather then the universe expanding is based on the energy requirements for an expanding universe verses a contracting galaxy.
If the red shifts are actual indications of expansion, then the universe is not only expanding but accelerating as its distance from us increases.
Acceleration requires energy.
Where do we get enough energy to accelerate the majority of the universe to velocities close to the speed of light.
On the other hand...
The contraction of a galaxy would not require an energy increase but could occur with a balance of energy conversion of one form to another.
A contracting galaxy does not even require that the contraction must continue, but that some cycle is in effect regarding its diameter and density.
I am not intending to suggest that this idea has to be correct, however I do think that all perspectives should be considered.
I realize that the prevailing theories have saturated our thinking to the point that it is difficult to approach an observation from another perspective.
Because something takes an effort doesn’t mean it is wrong.
Your comments are appreciated and may your universe be always expanding.