Hello all. If two clocks are at rest relative to each other and are synchronized using the usual Einstein synch procedure, under what conditions will they appear to be unnsynchronized to another observer who has always been at rest relative to them? Also, if an observer previously moving relative to the synchronized clocks ( and so seeing them out of synch with each other ) accelerates ( decelerates ) to become at rest relative to them, will these same two clocks then appear to be in synch with each other to the previously "moving" observer? My answers would be that i am unsure of the first part because accelerations would be involved to make any changes, and yes for the second part. Matheinste.