Forum:Alternate timelines vs. parallel worlds

In the thread Alternative timeline individuals, the issue came up of whether alternate timelines and parallel universes are distinct things in the Whoniverse.

The article Alternate timeline starts with:


 * An alternate timeline is a reality which is different from a parallel universe in that historical events have been altered by a time traveller or other temporal phenomena. These alterations can be prevented from having ever come to pass, although memories of them are usually retained.

Meanwhile, Parallel universe starts with:


 * A parallel universe was a reality created when historical events diverged from the main timeline. Unlike alternate timelines, these occurred naturally. Travel to parallel universes became impossible after the Last Great Time War.

I brought up the fact that there are "other realms that aren't alternate timelines, but also aren't part of the main Whoniverse" as a minor side argument against tossing individuals from non-canonical stories into an "alternative timeline individuals" category.

CzechOut pointed out that the only evidence for any such distinction is some vague comment by Sarah Jane in one SJA episode.

There are definitely other places where a distinction has been made in-universe. Sometimes it's just as simple as the Doctor saying "It's not an alternate timeline, or a parallel universe, or…", implying they're two different things; sometimes it actually explains some difference. And maybe in general there's more of a sense of "wrongness" when the Doctor talks about alternate timelines than when he talks about parallel universes.

But I sincerely doubt there's anything like the clear, solid distinction that we're making on this wiki. And there are probably a lot of contradictions. On top of that, these aren't the only two terms that are ever distinguished; there are also alternate histories, strands of the multiverse, and so on, which are all similar and related ideas but with different connotations. And that's not even counting things like the bottle universe from Interference, the bubble universe from The Doctor's Wife, E-space, the universes before and after this one, the universe next door, etc., all of which sometimes serve similar narrative purposes.

Even though we have in-universe evidence that the Doctor can clearly distinguish them all, if he never gives us enough information to make that distinction, we shouldn't be trying to make one up on our own. --70.36.140.19 08:24, September 18, 2011 (UTC)

By the way, I believe the distinction between "alternate" and "parallel" in SF/AH fiction in general comes from Poul Anderson (or at least Niven credits him with it). In his tradition, an alternate world is a parallel world where there is a clear single point of divergence. But I don't think that's relevant to the Whoniverse. (Or, rather, it's probably true in some sources, but not others.) --70.36.140.19 08:36, September 18, 2011 (UTC)