The Island Exists In Order That It Doesn’t Exist
I think we can assume that the bomb went off (if it didn’t, that would be lame) and ‘the incident’ was averted. As Miles pointed out, it could be that the bomb detonating was ‘the incident’, but I think that this outcome would be a little lame as well. So the island and all those on it when the bomb exploded are gone. Where does that leave us?
This would mean no record of this episode in our linear history. That is, by only observing the events that we have record of in our timeline, there was never an island. But consider the possibility that along our straight, linear timeline are loops. Loops that leave our linear history but then join back to where they left off the linear path. For all intensive purposes, the events on the loop never happened. But they did. They happened in order that they never happened.
There is now no island, because it was blown up. But it was only blown up as a result of the actions of people who were only there due to ‘the incident’ and so the subsequent plane crash. Which, due to the bomb, didn’t happen. This has now created an infinite time loop, which in effect, doesn’t exist.
So how does Jacob fit into all of this? He’s from the future. He’s here to make sure that all these events occur so that the island never existed. Why? That remains to be told, but I’d imagine that the result of the island existing has disastrous effects in the future of the world. Jacob is able to influence actions and events as he can travel through time in a more controlled fashion due to the island’s time-travelling capabilities being further understood in the future. Remember Jacob sitting on the beach with the Black Rock in the distance. He’s been here, at various points, from the beginning.
I know there’s holes in my theory and questions unanswered, but I’d love to hear some feedback.