Jacob's Loophole by LockesFaceCrab

Here's a crazy idea heavily influenced by many theories I've read. Please exuse any typos. I'm writing this off the top of my head with little thought - but I have a simple idea that may fit the overal structure of Lost.

We know the island has seen many iterations of people arriving, destroying, corrupting, i.e. Jacob and MIB's conversation on the beach.

I think each iteration takes many, perhaps 100's, of years.

The last iteration before the plane was probably the Black Rock (or maybe there were others between 815 and the BR, but probably not. Dharma was part of the 815 loop, not a separate one in and of itself.)

Each time, a different group of people comes to the island and starts the process of fighting, corrupting, destroying all over again.

I believe the difference in this iteration is the sideways universe. Somehow, at the point that 815 crashed, a sideways universe was created containing all the same people on 815. I'm not sure how it was created, maybe jughead, maybe not.

Think about it: the sideways universe contains versions of all our characters but they make better decisions. Even Sayid. He is still a killer, but he only killed when put into a corner by Keamy.

Going back to Faraday's metaphor...a small stone doesn't change the river of time, but a boulder makes a big difference. As mentioned in other theories, it splits the river. But the two new streams must converge at some point.

This is Jacob's loophole. He knew MIB was mucking about in time to find a loophole to kill him. So, he used time to build his own loophole, i.e. he changed time to create a sideways universe in which the characters are no longer saddled with the scars of their painful past. As a result, when they come to the island they won't fight, corrupt, or destory. They will live in harmony on the island and protect it in peace.

I think the sideways universe is going to merge with the current timeline. All our current-timelien losties will die on island. This will be the big sacrifice. The sideways losties will somehow end up on a plane (or maybe some other medium will bring them to the island.) I predict the last one alive on the island will be Jack and he will learn, understand, and most importantly, believe or have faith that two versions of himself cannot exist in the same universe, so he will kill himself, therefore allowing the new vehicle carrying the sideways losties to land on the island and begin the new, good iteration that will result in saving the world.

This is why Lost was originally called the circle. This time the circle will be a good circle, not the corrupt one that MIB referred to with disgust.

Jacob's loophole is getting alternate versions of the same people to the island, people who's previous versions were already on the island. This was never done before in any of the iterations and its the reason the new one will work.

The last poignant scene of Lost will be our sideways losties beginning a new iteration on the island in 2007, living together in peace, not knowing that alternate versions of themselves made the ultimate sacrifice to ensure that they could get to the island. Maybe the very last moment will be Jack finding some evidence of his previous version, a little knick-knack that causes him to have a flash of connection to the previous iteration.

As one final side note - maybe the new Jacob and MIB will be one or two of our current losties that sacrifice themselves to make way for the new, improved sidways losties. Maybe one lostie will willingly take the responsibility, and that person will be the new Jacob. Another will be forced into the position and not be happy with it, meaning he/she will be trapped, and that person will be the new MIB. That's why the MIB and Jacob have supernatural powers, because they are beings that exist outside of the dimension they are in because they died in order to allow a different universe version of themselves inhabit the island at the same time that they are there. The act of "merging" with an alternate universe version of yourself destroys your physical form, thus giving you the powers that we see exhibited by MIB and Jacob.