Do we know if the instantaneous/observed acceleration due to the vacuum is directly proportional to distance or possibly? (ignore any gravitational effects) A~D ? A~D^2 ? A~D^(1/2) ? A~D^(-2) A~D^(Other) ? OR A= constant (edited as I forgot this one) If not, is there a best guess/fit or simply not precise enough data? Feel free to correct my question if it is simply a bad question. I didn't see this directly address in any thread; if I missed one, a link would be great.