Spacetime and conventionalism

Salmon, following Reichenbach and others, maintained that distant simultaneity was conventional in a special relativistic world in a way in which this was not so in pre-relativistic spacetime. This paper surveys and criticizes a number of proposals to unpack this claim. It goes on to argue that if the claim has validity, it rests upon differing facts about epistemic accessibility of temporal relations in the different spacetimes, and not directly upon any facts about differing causal structures in these worlds.