Howling:Crossing timelines

We know that it's dangerous, and possibly difficult, for a Time Lord to cross his own timeline. And the same is true for non-Time Lord time-travelers.

It's also dangerous, and possibly difficult, for two Time Lords to meet out of sequence. But if they're not both Time Lords, it doesn't seem to be any problem at all.

We've met time travelers in various episodes and novels who remember adventures the Doctor hasn't had yet. And we've actually watched the Doctor meeting (off the top of my head) Sarah Jane, Mel, Sam, Fitz/Kode/Kreiner, Rose, River, Amy, and Rory. And that's not even counting multi-Doctor stories, MA/PDA/BFA stories that take place in the Doctor's past, etc. It doesn't seem to take any special effort, and there are no negative consequences other than a bit of mild confusion.

So, why is it different?

I'm pretty sure we've never gotten an answer on-screen/-page/-CD, so I'm happy with either out-of-universe explanations or pure in-universe speculation. I'm curious what people can come up with, because I can't think of anything. (Especially since River is apparently part-way to being a Time Lady, or at least has a "Time Head", and is also the most out-of-order…) --173.228.85.118 05:52, August 11, 2011 (UTC)

Sure we have. Series 1, FATHER'S DAY. Boblipton 10:57, August 11, 2011 (UTC)

In the 20th-century run of the show, there were a few stories that dealt with people crossing or trying to cross their own timelines. Apart from the multi-Doctor stories, there was Day of the Daleks, in which the Blinovitch Limitation Effect was mentioned, and Mawdryn Undead, in which the Brigadier encountered himself. There are probably some others but they're failing to spring to mind. A search of this wiki for these episodes and for the Blinovitch Limitation Effect might provide more information. It's worth bearing in mind, however, that the Doctor told Rose, in Father's Day, that the consequences of such things had changed because the Time Lords were no longer around to limit the damage. --2.96.21.100 15:47, August 11, 2011 (UTC)