Let`s make a new experiment to test the principle of Relativityof Simultaneity. Let`s make the arrangement so that when thetrain ends coincide with the embankment ends 2 small slits putat the train ends are allowed to open for a brief time to permitjust 2 photons to enter from a source put behind the train ( onthe opposite side of the external observer),,, let`s make thedistance between the 2 slit small enough comparable to thewave-length of the photons to cause an interference pattern.This brief opening of slits can be done mechanically or evenopticallyFor the external observer, he sees both slits open at the sametime and therefore the 2 photons entering the 2 slits and createan interference pattern on a screenBut according to Einstein interpretation, the train observer seesthe front slit opens before the back slit. And it happens at onetime, only one slit opens while the other is still closed. Thereforeaccording to the train observer, no interference pattern couldever occur. But when he looks at the screen from his window, hewill see an interference pattern on the screen.Can the train observer now explains why this interferencepattern occurs when just the slits open one at a time?