Local coordinate system in GR observed. If one considers coordinate systems in General Relativity. I think, if I understand it well enough, that in GR space & time and or in space-time a coordinate system depends on locality, e.g. on an average distance between galaxies an the total amount of mass, DM & DE all together concerned in such a ‘local environment or better the local density of that ‘local’ environment Can or will any of our specialists (e.g. ST, Chronos, Marcus, Garth) give a mathematical relation for an observer who finds himself in another local environment (with another density, at a distance measured in his own coordinate system and with a relative speed als expressed in his own local environment). For myself I see to many pitfalls even to make an attempt to try this. Many thanks in advance.