Er, can you characterize which post-Newtonian correction/s is or are of non-negligible order here for Milky-way millisecond pulsars? Where do they enter, if n

Er, can you characterize which post-Newtonian correction/s is or are of non-negligible order here for Milky-way millisecond pulsars? Where do they enter, if not extremely close to the pulsars themselves? I'm curious, because we use them to test, among other things, |\alpha_3| in the PPN formalism alpha-zeta notation. Along the way you necessarily get a very good characterization of the transforms available on local arrival times in different coordinate systems and can probe other PPN parameters. (cf. Kramer, sec 4 and 5.1 free version: http://arxiv.org/abs/astro-ph/0405178v2 http://arxiv.org/abs/astro-ph/0405178v2). More generally, do you object to systems of coordinates that are in-practice recoverable by a wide variety of observers? We sure aren't Eulerian observers of the Milky Way, but does it really seem parochial or idiosyncratic to take a Eulerian approach to its matter? > If four observers cannot agree on what was your exact location at time n Find four observers who see the CMB (and matter in the bulk) as isotropic and homogeneous, who measure the same temperature of the relic photons, and who have a direct line of sight (with improbably good telescopes) into the relevant part of the Milky Way, and they can agree very precisely on your location in a cosmological frame constructed like the standard one used in this tiny patch of spacetime. The tricky part is that the light travel times are long compared to chaotic movements of individual humans, and the choice of gauge has to be agreed and the observations shared. > If you're in the middle of nowhere and not moving at relativistic speeds Where in spacetime is the middle of nowhere? What's materially different for a relativistic observer moving through the same general curved spacetime (especially if "the middle of nowhere" is, say, a large region of extremely-close-to-Minkowski spacetime) as a non-relativistic one? While you're there, what's different for an accelerated observer in the same region? Are you saying that something more than a Lorentz transform would be needed?