How do you think Time's Arrow started the first time?

If they wanted to break the loop ...

Picard from post-Nemesis goes back to 1890-whatever and retrieves Data's head before Time's Arrow Picard gets there.

If they wanted to really screw things up ...

Post-Nemesis Picard replaces Data's head with B4's head, then watches as the whole damn universe implodes.

 

My new theory as to how the MU is created is that MU Picard time travels back to San Fran and replaces Data's head with Lore's.

 

Guinan would be going around thinking "Wait a minute. Things aren't supposed to be this shiny. Something is wrong."

 

Yeah but within the same universe it's good practice to keep the rules internally consistent.

For all we know, when Nero went back in time he actually went into a parallel universe that hadn't diverged from the prime one until his arrival.

 

Ah, but we're not talking about the point where Data's head was left; the incident which sparked the whole investigation off was when the archaeological dig unearthed the cave, centuries later.

Come on, both those are clear example of a "parallel universe" rather than an "alternate timeline"

 

True. But the head is still there, regardless.

 

True, but since it originates from a future completely distinct from the Abrams-verse, it might as well not be.

 

I enjoyed the episode the first time that I saw it!!

 

How do you think Time's Arrow started the first time?

Probably a poker game in Riker's quarters with all of the senior staff minus Picard.

 

Shouldn't Data's head be in that cave right now, it was left there in the late 1900th century... It has happened already.

 

^ Depends on what you mean by "right now".

In the prime timeline, we know what happens - the head is found and reattached.

Data's head could also turn up in the Abramsverse. I'll repeat: At the point in the late 19th century, where the head is left, both the prime and Abrams timelines are possible futures. So when 2233 comes around and the timelines diverge, the head will still be there - in both timelines. (If you're looking for an easier explanation as to why: Spock Prime still exists, doesn't he? He comes from a timeline that no longer exists, yet he still does. Same thing with Data's head.)

Who knows if any of the nu-characters would know what to do with it, though. Dr. Soong may not even be born in the Abrams timeline (we don't know how old he is when we first meet him), so there may not be a nuData. If that's the case, whoever finds the head may not have any idea what it is or what to do with its technology.

 

Data's head is tied to the Prime 24th century - I would imagine that at the point of timeline divergence (when the Narada attached the Kelvin) any remnants of the Prime Timeline would appear to fade out of existence, ala changes in Year Of Hell (or even Back To The Future!)

OldSpock still exists because he came through the gateway after the point of divergence, hence he was travelling to a timeline that already existed