The Rietdijk-Putnam argument occurred to me several years ago when I was still chasing relativity by the tail. I didn't learn that Rietdijk, Putnam, and Penrose had advanced this argument till yesterday. Weird. Anyway there are direct testable consequences if this argument is valid. Not only is it testable but if it holds it would provide a mechanism for measuring astronomical distances through directly controllable parameters. We obviously couldn't use invading aliens, rather we would need to use any uniquely identifiable event or event sequence. Supernova or more subtle events come to mind. The Rietdijk-Putnam argument (empirical consequences): 1) The degree to which two nearby recording devices in separate frames disagree on the timing of an identifiable event is a function of the distance of the object being recorded and the relative frame shift of the two recording devices. 2) Given sufficient distance to the event and proximity of the devices, device B could inform device A about an event that device A couldn't know if information is strictly limited to the speed of light. By knowing the relative frame shift between the devices A and B and the degree to which they disagree on the timing of the event it becomes trivial to calculate the distance of the event for any given frame. The greater the [tex]\gamma[/tex] between A and B and the greater the distance to the event the more A and B will diverge in recording time of event. Since we know the [tex]\gamma[/tex] between A and B we can easily calculate the distance to the event for a given frame. If the Rietdijk-Putnam argument empirically holds we must give up the notion that that information is limited to the speed of light, irrespective of any notions of hidden variables. My take: It will not work. The fault lies with the Rietdijk-Putnam argument and not SRT. Resolving this, at least to my satisfaction, essentially resolved my quest to find problems with SRT. My personal analysis is several years old and would take time to reformulate. In essence the problem stems from mistaking a definition for a physical state. I'll try and illustrate pictorially by assuming a priori that the Rietdijk-Putnam argument is false. Two frame shifted observers, A and B, observe an event in the Andromeda galaxy. They record the time and compare notes. They notice that the only difference in the timing of the event is directly attributable to the [tex]\gamma[/tex] that defines their local disagreement in simultaneity. In fact they may even choose to define the event itself as t=0 without complication. How can this be if the same [tex]\gamma[/tex] defines the difference in distance to the event to be a full light day or week shorter for observer B. Simple answer: due to the frame shift, B must define past events on a different time scale that A does. Notice that given the finite speed of light these events are in fact in the past for both observers. The only question is the rate at which the laws of physics allows them access to that information. How far in the past is purely a definition imposed by their respective (frame shifted) points of view. The relativistic interval still holds, as does the Relativity of Simultaneity. The statement on http://en.wikipedia.org/wiki/Rietdijk-Putnam_argument This statement is not only falsifiable but must be false under the principles of relativity. So why does the Rietdijk-Putnam argument remain, or more specifically the above wiki quote, remain unchallenged?