Hi guys, I have studied special relativity for a while now and am doing a project for one of my physics classes on it. The relativity of simultaneity is a concept that I easily grasped when I began reading S.R. and time dilation was the hardest (easiest now). I grasped it (simultaneity) easily because it I found it quite intuitive. The problem is, the way I see it presented, the relativity of simultaneity seems completely Newtonian and to be expected if light has a finite speed. I see it causing an asymmetry and contributing no symmetries, this seems contrary to a good physical law. If these concepts where true, one could easily establish (I think) that events ARE simultaneous when perceived as simultaneous by a system of co-ordinates at rest relative to the two events. Does this all dissolve if one of the events is moving relative to the other? The presentation that I see the most often is the one with the train and two poles. Like seen at about 2:13 : http://www.youtube.com/watch?v=AZ6N85lNgHY&NR=1 I have a lot of books on S.R. and I am starting to get into the complicated ones. I noticed that in the original Einstein paper, On the Electrodynamics of Moving Bodies, he makes no reference to any such thought experiment and rather opts for a mathematical approach that I cannot follow. A preliminary look into (I have not read it yet) Six NOT SO Easy Pieces by Feynman seems to show the same thing. I am guessing/hoping that all this train stuff is just a poor explanation/metaphor or this is something that has been corrected by general relativity. I would really like to be able to talk sensibly about this stuff to laypeople, to go on about causality and concepts such how S.R. changed our view of action at a distance. Much to my dismay, I have also had much difficulty finding satisfactory explanations of E=mc^2 and changes to mass/energy in a body moving at a relativistic velocity. Some of my books make a poor attempt at explaining relativistic momentum and I believe that the above comes from that equation and some combination of the kinetic energy and work equations. As I write this stuff, I get the impression that I am close to grasping these concepts. I would appreciate it if any physics undergrads or higher qualified individuals with formal S.R. training could help me. Oups, I just noticed that I messed up the title, too bad you can't edit those things.