" 
 :Why would ""any rational viewer [have] to assume that Desmond did in deed time travel""? The whole ""before the island"" experience could easily have been in his mind, and perhaps the Island is giving him visions in the same way the Jack saw his father and Kate saw the horse. It's not our job on Wikipedia to speculate about such things, and we certainly should not discredit the words of the show's writers, based only on such speculation. -  → Ε "