Why time travelers haven't fixed the 40K universe.

[Aaron LeClair]

Could be that the Ordo Chronos was once more than a branch of the Inquisition and dates back to a time only the emperor would know do to him creating the group to protect the time line... But that's just crazy talk from me.

Anyways: [url]http://wh40k.lexicanum.com/wiki/Ordo_Chronos[/url]

[Jmaximum]

Could be that the Ordo Chronos was once more than a branch of the Inquisition and dates back to a time only the emperor would know do to him creating the group to protect the time line... But that's just crazy talk from me.

Well, as we can all see, time travel is mostly a philosophical/theoretical conversation.
There has been mention of it multiple times in various 40K books, something to the effect that some ships, when travelling the warp, appear months after they were supposed to arrive, or before they even left their point of origin, etc. It's always mentioned in passing, though, never as a main plot hook. So according to 40K fluff, it may potentially be possible for a ship to leave in M41, and jump back to M-whenever.
Aaaaaaaaaaaaaaannd a bunch of my colleagues distracted me, and I forgot where this was going. Nuts.

[Lunar Camel]

Actually they did go back in time. But they went to far and screwed up the fantasy world.

[Ravingbantha]

There are several approaches to this;

1) Time is immutable, if you travel to the past you were already there and what you did is already reflected in the history you know.

2) Time resists change, any attempts to change it are resisted. You attempt to kill an assassin but you are jostled and it is your shot that kills the target etc.

3) Do you interfere at all? Can you know the long term effects of your action? would trying to correct something actually make matters worse in the future. I cannot remember the name of an OK film where the USS Enterprise (the modern nuclear powered aircraft carrier) goes back in time to just before Pearl Harbour. They have the power and knowledge to prevent the attack but should they? what would be the effect on WWII and history of Pearl Harbour not occurring? In the end if I remember they copped out and the carrier went back to the future before they could interfere.

There are some other options:

4) Multiverse theory, by traveling back in time, you create a new universe, however the old one exists unchanged.

5) You can only change the details and not the outcomes, the HH was destined to happen, nothing can change that. But by going back you may change the players. Instead of the Horus Hersey you may end up with the Leman Hersey or the Corax Hersey

[Valkerie]

How do you know that what you're changing isn't actually bringing about the crisis itself? There have been more than a few stories where the protagonist's attempts to change history for the better actually created the problem in the first place. After all, since nobody really knows what happened and why, your appearing in the past may be the very thing that causes all the troubles.

[Spider-pope]

Because 40k is a fixed point in time, so it can't be changed. That or wibbly wobbly, timey wimey.

[Jmaximum]

This going to get hairy....
Suppose you dd go back in time, and change something: would your memories reflect both knowing the world prior to the change AND knowing the world with the change? You are the same person, actively experiencing both, after all. This is fantastically demonstrated in Steven king's Dark Tower series (book1 or book2, I forgot. Somewhere in there.)

[0rph3u5]

Changes to the timeline in 40k might be a bit difficult because of the way the Chaos Gods are ... as Codex: Chaosdaemons reminds us about Slaanesh, the moment the Dark Prince began to exist, she always had existed

By extension this means that each Chaos God exist at least partially, if not completely uneffected but linear time, and any Time Traveler would have to account for that - which would require a understanding of Chaos which only the Eldar Harlequins are said to have and do not readily share

[Fueldrop]

Another heartening thought:

You know how there's that joke "law" of time travel that whenever you change the past you increase the chances of Germany having won world war 2?

What if every time you try to change the 40K universe for the better, you make things worse? What if the current 40K universe is the result of several iterations of people trying to make things better, only to send things further and further down the drain?

[Morgrim]

The sheer scale of the setting would make changing thing really hard too. Okay, so you're back in time before a major event. Great. Can you get to a suitable location in time, remembering how long travel takes? If yes, can you actually do anything to significantly change it? There were plenty of warnings in the early stages of the Horus Heresy and they were ignored. Seers canonically exist and tend to get shot/eaten/murdered fairly frequently. It does seem that the only reliable change one could carry out is going to be assassination of a target before they do [x], and the targets that have a major influence on a galactic scale tend to be really hard to kill.