oriel36 wrote:
The motion of the visble stars of our galaxy around a central axis
will change their orientation to the external galaxies,as you
creatures have the visible stars stuck on an astrological framework
there is no possibility of appreciating this great cycle,even in
principle.
..
No. This is not the case.

Of course we can recognize that the "fixed" stars in the Milky Way
galaxy really do move, slowly.

Just as we realize that precession of the equinoxes is a real
phenomenon.

We still use the position of the equinoxes, or the "fixed stars", as a
background, as a reference frame, because they move so slowly that
they serve as *reasonably* fixed landmarks, but, naturally, a closer
approximation to an inertial frame *is* possible through using distant
galaxies as a reference.

Even the galaxies, though, are in motion.

But we are talking, as I noted in a previous post, about a matter of a
hundredth of a second per day, even with the largest correction, the
one for precession. The precession cycle takes about 24,000 years.
Compare that with the *one year* cycle that causes the difference
between the 24 hour synodic day and the 23 hour and 56 minute sidereal
day.

If you advocate adopting the system of Tycho Brahe because you are
annoyed that we sometimes ignore the small precession effect, you are
straining out a gnat yet swallowing a camel. If that is not what you
are doing, then your point is still a mystery to me.

John Savard