args.bungie.org

Just out of curiosity why has it been dismissed when there is evidence for it? Is there information I am unaware of?

I believe that Cortana only has a limited lifespan. She was considered a "smart" AI and was able to operate outside of her own parameters unlike "dumb" AI's that we limited. Eventually she would acquire so much information that she would "think herself to death".

In an interview with...someone from bungie, I can't remember who, in context with the halo storyline we were told that Timetravel was a sort of bogus way out and that they were avoiding it for the Halo storyline. From what we've been told, this ARG is exclusively halo related, and as such timetravel is, for now, out of the question.

What about the books, though? Or are they speaking game-wise, which I suppose would include an ARG?

As far as Halo canon is concerned, the official stance is that there isn't any. That does not exclude time dialation from slipspace distortion and relativistic effects, but 500 years into the past? Not so much.

Ok you want evidence of time travel...here it is. Nicole Spartan 458 was yanked from 2552 into the 21st century by a slipspace anomaly brough by the ONI stealth ship Apocalypso and is still guarding Nassau station. That is why she is in the DOA game and yes it is cannon. Furthermore It was and ONI ship that crashed in ILB, possibly the Apocalyspo. It may not be a tool they wish to utilize often...but time travel does happen.

It isn't canon. There were only 150 candidates for the Spartan - II program, of which 75 were selected. This is why no Spartan has a number over 150, since Nicole has the number 458, it is quite obvious that if it were canon, it would create major holes in the plot.

http://en.wikipedia.org/wiki/Nicole_(Dead_or_Alive)

So Bungie put out a non-cannon spartan? With as much control as they keep over everything halo, I find that hard to beleive.

I am saying they put a non-canon Spartan in the game yes. I severly doubt that DoA is part of the Halo canon. Your link doesn't lead anywhere useful as well.

The slipspace accident that sent Nicole to the 21st century occured in the halo universe. The ONI ship was the one in I love bees. Even if you discount Nicole, I love bees is still cannon and that involved time travel.