I understand that the theories of expansion of the universe lack a correct physical logic since the Big-bang is analyzed under a simplistic theory far from the physical procedure of explosions.
The premise for studying this explosion theory should first contemplate a logical analysis of what an explosion is.
All explosions of any kind take place within a medium that is stable, and an element that explodes and expands along this medium.
But the medium does not expand only the exploited element is expanded.
And the same should have happened with the Big-bang, that with the explosion of a gigantic cluster of matter and energy, it is this cluster that would expand, not the space and time where this cluster of matter and energy was located.
It is a tremendous mistake to consider that out of the nothing of space, time, matter and energy, a great explosion would be built so that a whole gigantic universe would emerge from that nothing.
That makes no physical, mathematical or logical sense.
It is simply impossible. Now, if from a large explosion of matter and energy it is produces a large number of pieces of matter (galaxies), the expansion produced will be spherical, and therefore the separation between the pieces of matter will vary depending on the angle of dispersion: the more distant will separate more quickly and the closest ones more slowly.

And that is what happens to our observations, that as we discover more distant galaxies, we measure much greater separation speeds between them.