Lost!

[Ghoulish Delight]

Originally Posted by bewitched

I'm also still standing by my feeling that I think they are skipping through time based on a parallel universe or multiverse theory, both of which postulate that all times exist concurrently and moving through time would not be skipping forward or backward linearly but moving from one already existing world (not constrained by time) to another. The most reasonable mode of travel between universes on the show, IMO (based on what I've seen) would be through wormholes (which, while not general referred to in most multiverse theories, does provide a means of travel which is not rejected in the theory). In this scenario, one would in effect, exist in two places at one time since the person entering the wormhole would only "appear" to be gone for an infinitesimally small fraction of a second to the people observing (ala the movie Contact).

But that's completely inconsistent with Rousseau's account of Jin disappearing when the flash happened.

This would also explain why "windows are only open for a finite period of time" (as Eloise stated)

The "windows are only open for a finite period of time" because the island moves. The room with pendulum tells them, "during the period of time between x & y, the island will be in this location. After time y, the island will move and we don't know where it will be." It has nothing to do with time travel. There has been nothing that says the island itself travels in time, it seems to be moving in space instead.