You've got a gut-level understanding of the problem Einstein solved with reference frames. Your wacky math aside, the question of how do we know where we are in space, in relation to the rest of space, is exactly what many many philosophers, theoreticians and physicists struggled with for a dozen decades. We got ideas about "ether," the boundaries of the Universe, and all the rest of cosmology from the struggle to understand just that question.<br /><br />Einstein pointed out that it in fact doesn't matter. You can behave, and make measurements which, for the most part, treat your frame of reference as the stationary one.<br /><br />Lots of wacky, counter-intuitive effects proceed from this, such as the twin paradox, but so far it seems to be an excellent description of what's going on.<br /><br />It also means that yes, there are parts of reality that we are forever cut off from.<br /><br />For example, we don't know what's going on, out at Saturn, right this minute. We'll know in about an hour, what was happening now, but we can't know <i>now</i> what's happening now.