Jughead did not cause the alternate timeline by SDJ

Okay, I have thought this for a couple weeks now. It just really feels like to me that either the FDW caused the alternate timeline or some other magnetic force that we don't yet know about. The losties just flashed from 1977 to 2007 without a scratch except of course Juliet who was the closest to the bomb and still only died from a fall down a hole and not from being blown up. The bomb could still be in that hole or maybe it could have been a dud and hitting it a hundred times would have no effect still. Whatever caused the ATL it's my belief that it happened way before 1977 and the losties had nothing to do with it. The losties didn't change anything which would prove Farraday's first point, that nothing could be changed. MIB could have manipulated someone way back in the 70's to make some kind of huge change with the FDW or some new way of moving the island which is maybe what I call "island ! submarine mode." Or Jacob moved the island down. I just don't think a nuclear bomb went off at all. It just doesn't seem plausible because Jack, Kate and the rest could not survive this and the flash back to their own time like bam without being physically affected.

So there it is, my first theory posted on here. Ever since like the third episode of season 6, I felt this way and it's been bugging me that they could survive a nuclear blast whilst they were like right next to it. Hmm......