Much of the discussion about the conventionality of simultaneity makes use of a formulation given by Hans Reichenbach (1928). Jammer (Chapter 9) discusses this fully; I shall summarize the ideas here. Reichenbach, like Einstein (1905), considers a light ray that leaves location A fixed in some inertial frame at a time that he calls t1, is reflected at location B, and returns to A at t3; t2 is the time that a definition of simultaneity in the given frame will assign to the time of reflection. He takes light to be the fastest possible signal, and argues that any event at A that is later than t1 and earlier than t3 could be taken to be simultaneous with the arrival of the light at B, and so he takes the range of possibilities for t2 to be given by t2 ¼ t1+e(t3–t1), where 0oeo1. Standard simultaneity (Einstein’s choice) corresponds to e ¼ 1/2.