I refer to two threads in the Relativity section - https://www.physicsforums.com/showthread.php?t=221494 which is titled 'Revisiting the lesson of the "Relativity of Simultaneity"' and this https://www.physicsforums.com/showthread.php?t=213911 entitled "Simultaneity". My understanding of special relativity is that simultaneity of two distant events is observer dependent, and therefore has no physical significance. Despite excellent and detailed answers from PF members ( JesseM mostly) neither poster will accept this, and other posters have now joined in, with statements denying conclusions from SR. If someone does not accept the validity of all of SR, and presents arguments purporting to support this view, are these not 'private theories' as defined in the forum rules ? What about sticking to the topic ? The second thread I cite has gone from a question about simultaneity ( answered in the second post) to a discussion of a private theory in which the arrow of time is attributed to cosmic expansion. The reputation and quality of the PF depends on application of the rules, and I think it is slipping.