LAST EDITED ON 02-10-10 AT 09:55 PM (EST)

I'm not too into science even though at one time I read a lot of science fiction, including classic time travel stories. So I am not even trying to deal with physics here, but this is my understanding of how these writers are treating time travel.

As someone (Daniel?) explained during Season 5, a character's experience of personal past and future is a continuum no matter what time period their body is inhabiting.

As we saw, the castaways in 1977 are older than they were in 2004. Those who got back to LA and those who stayed on the island are the same three years farther along in experience at the end of Season 5 than at the outset of the series, whether they went off island, time jumped to 1977, or ended up living in "the present" on the island.

Darlton has said that they're not really into the time paradox theme. They're more into the type of time travel where the people who came from the future were always part of the influences that shaped what happened. For example, Charlotte recognized Daniel because a version of himself that was still in the future had ended up In 1977 and helped her. That had already happened in Charlotte's world, even though Daniel hadn't yet arrived at the point of his existence where he had met Charlotte.

Ben had always been shot by Sayid and lived. Sayid couldn't change anything.
Eloise told Desmond he couldn't change what happened, that it didn't work like that. That things are meant to happen a certain way. The older Eloise knows that she killed her own son. But she didn't try to keep him from being recruited by Widmore and going to the island. It seems like she would have wanted to change that, but it appears she thinks it's futile.

But Daniel thinks Jack CAN change what happened and make it like it never was. Daniel is quite the expert on time travel, but I don't think he has a clue about the island the way his mother does.

Juliet tells Miles that it worked, but what worked? Does she mean the bomb went off? She "knows" that because it was the last thing she knew, but what does she know about whether it "reset" everything? Spirits don't seem to know everything in this LOST world. They seem to be hovering but not omniscient.

What if the Flash Sideways is not a reset? Detonating the bomb didn't make it exactly as if nothing had happened in 2004. Clearly the Flash Sideways doesn't show the same journey to LAX that was unfolding in the Pilot.

I sort of think the Flash Sideways characters are more like versions of themselves that are not exactly pre plane crash but are more like products of the experiences they've had on and off the island since the crash. They don't remember, but they recognize each other on an unconscious level. More importantly, their characters seem changed or evolved in ways that are fairly consistent with the lessons they learned on the island. (At least the main characters, the ones that matter, not the Marshall, who died shortly after the crash, as did Arzt.)

I think it goes along with the theme that these people on 815, the main characters, were all deeply flawed and needed a second chance on this earth to find their true destiny. Not to change it, but to find it. The purgatory theme only they aren't in an afterlife. Purgatory is on this earth.

If there is a complete reset, then their past suffering and work towards redemption is totally meaningless. So I think they are all changed by what they "went" through even though apparently it never happened.

Jacob and MIB discuss that it only ends once, but until it ends everything is just progress. I don't know if that fits with Eloise's understanding or not. That statement seems to intimate that what lies in the middle is somewhat fluid. However, the word "progress" is more in line with a continuum that is fixed.