How many new timelines have been created?

[Alidar Jarok]

Don't try and think about the time travel in that episode, it's just a tangled mess

 

[CoveTom]

I agree, although I'll argue there's a third that's similar to the first and that's a predestination paradox. Some method of time travel brings you back in time to create the events that led you doing what you did in the first place. IIRC, Time's Arrow was one of these (although I know there are others). There's also something that Daniels said in some Enterprise episode that could suggest even more time travel types, but I'm too lazy to remember what it is, so I'll ignore it.

I don't think there's any doubt about the predestination paradox, especially since both Bashir and the time cop dudes in "Trials and Tribble-ations" discuss it, but I just wouldn't have considered that a 'different' method of time travel. You're still traveling back and forth in your own timeline without creating a different reality, universe, or timeline. It's just that instead of it being a free will choice, you are 'fated' to do so in order for some event to happen.

 

[xman]

E² was one of my favourite time travel stories ever. There can be no doubt that things were changed but nobody is sure exactly how. Why do they remember meeting their descendants if they never existed? I especially like that they never answer this.