I have a new theorem that explains the mysteries about why the explosion of Jughead didn't seem to have an effect on the island and a bunch of other things.
According to Lost, people having near-death experiences (including near-death experiences that end in actual death) flash between a sort of "afterlife" and the "real world." We know this because:
a) Charlotte Malkin supposedly died and when she was between worlds, spoke with Eko's brother Yemi.
b) As Juliet was dying, she muttered "We should get coffee sometime," "We can go Dutch," and thought, "It worked." We can assume this was because her consciousness was flashing between two realities: our reality and the flash-sideways, where she said these same lines to Sawyer at the vending machine in "The End."
c) (This is speculation) When Desmond turned the fail-safe, his consciousness went to the flash-sideways. I believe that this whole thing--waking up covered in paint, being in London, etc.--was the same universe as the flash-sideways because he got there in a similar fashion (exposure to electromagnetic radiation from turning the key--like being put in the electromagnetism chamber by Charles Widmore in season six) and just as in the flash-sideways, little things gave him deja vu, reminding him of his life on the island: hearing Penny say "It's not the end of the world," hearing the numbers, and seeing Charlie all gave him flashes of his real life just as, in the flash-sideways, seeing Charlie in the sinking car reminded him of "Not Penny's boat." Or maybe that's just the nature of any sideways consciousness, not just the afterlife. Anyway, the previous two examples still hold true.
Now, if Jughead's detonation really did cause what we knew as the incident, and everything that happened (the Losties crashing on the island in 2004, etc.) was a result of that, where was the bomb damage? The fallout? The residual radiation? And if the bomb was the incident, it must have opened up a damn big hole in the electromagnetic energy pocket--how would the Dharma Initiative be able to go in there and patch it enough to build the Swan? My conclusion is that Daniel Faraday was right when he said that humans are the variables and we can change the outcome of events. By deciding to set off the bomb, the Losties created an entire new timeline--a parallel reality--the flash-sideways. This is why the island was sunk in the flash-sideways. Because of the bomb. So flash-sideways Faraday was also right when he theorized that he had created this universe by setting off a bomb.
Or perhaps the flash-sideways timeline existed before they decided to set off the bomb. When the Losties time-traveled to 1977, they weren't actually in the past of their timeline: they were unknowingly in the flash-sideways. This is why:
The End/Theories goes into detail about how Eastern philosophies govern the show. Therefore, we shouldn't think of time as a straight line with past, present and future. So then how can you travel to the past? You can't! The Losties weren't in 1977; they were in the flash-sideways timeline.
When Charlotte Lewis was dying in Daniel's arms, she muttered a bunch of things that we assumed were a result of her temporal confusion: "Turn it up, I love Geronimo Jackson" was one. "You know what my mum would say about me marrying an American" was another. Then she said she thought she remembered Daniel from her childhood, and said "I'm not allowed to have chocolate before dinner." I think that these weren't temporal flashes. They were the same thing as "We can go Dutch"--her flashing between flash-sideways and our world as she was dying. It was the same flash-sideways we saw in season six, but thirty years earlier. She was recalling seeing Daniel when she was a little girl in the flash-sideways universe and Dharma was evacuating the island. As Charlotte was dying, she mistook this for her past. But it was the same world in which Oceanic Flight 815 landed safely in Los Angeles after flying over the sunken Island. Charlotte, as well as Ben Linus, never returned to the island because right after they evacuated it was sunk by Jughead. And as an adult in the flash-sideways, sometime after our Losties had moved on in the church, she started a relationship with Daniel Widmore and eventually told him "You know what my mum would say about me marrying an American."