Galactocentrism was established in 1925, which realised that our solar system is not near the center of the Milky Way. So, we are moving relative to the center of our galaxy.
In 1929, evidence was found that everything else is moving away from us. So we are moving relative to everything else.
In 1931, the Big Bang theory started superceding Galactocentrism, which was an acentrist model of the universe (where there is no center).
Everything else. Or anything else, if you select a single quark (presuming we don’t split a quark).
If everything is moving away from us, then everything is moving away from everything else.
It’s just that some things are moving away from us faster than they are moving away from other things
Everything else.
Galactocentrism was established in 1925, which realised that our solar system is not near the center of the Milky Way. So, we are moving relative to the center of our galaxy.
In 1929, evidence was found that everything else is moving away from us. So we are moving relative to everything else.
In 1931, the Big Bang theory started superceding Galactocentrism, which was an acentrist model of the universe (where there is no center).
But what frame of reference?
Everything else. Or anything else, if you select a single quark (presuming we don’t split a quark).
If everything is moving away from us, then everything is moving away from everything else.
It’s just that some things are moving away from us faster than they are moving away from other things