The turrets are only "sentient" in the sense that they're an AI. I don't think they are really connected or networked or anything with GLaDOS or any other Aperture AI's. Remember, they were a consumer and military product. They were designed to be stand-alone.
It's besides the point really. The automated facility maintenance systems do not have to be sentient to maintain the system. You only need real intelligence (which is not necessarily the same as sentience) to handle truly unforeseen events / catastrophic system failures.
Well, since apparently this thread has taken on a life of its own I rescind my earlier merge offer.
There is a point in the game (2) where you are told all systems can run on 1.1 volts. Not hard to obtain/sustain. Potatoes for example...
I saw a timeline where someone appropriated that portal 2 is actually 27 years (9999 days) after portal 1, explaining the plants (all fast growing) and the fact that all the paper/chairs/wood/metal hasn't rotted to kingdom come yet.
Also, i think that "I'm different" turret was being manufactured as they jumped caroline's brain into Glados, thus recieving an imprint/echo of it?
ITT: Huge leaps of logic.
I think everyone's missing the point here. I highly doubt Valve has thought so far into Portal that they had all of this planned out since Portal 1's inception. They're writers. It's their jobs to try to make the most sense out of a semi-developed plot. Portal 1 didn't offer much to go off of. 50,000 is a ridiculous and unrealistic number. Just accept it and try to analyze the story for what it's for. We all know that no company could develop a facility that could maintain itself for even 10 years in the 90's. Besides the year Portal 2 take's place has changed over development. When it was announced in Game Informer it stated that it had been over 150 years since Portal 1, not 50,000.
The number I had always heard was in the hundreds, like 300 at most. Anybody who thinks Portal 2 is 50,000 years after Portal 1 is smoking some serious crack-cocaine.
Wow. I wonder if they realize how long 50,000 years really is. Modern man has only been around for about 10,000 or so.
It's already bad enough that they retconned... Chell, well her appearance. In P1 she looked like a state prisoner sold to Aperture: remember the line "you are not even a good person, good people don't end up here"? There's hoping that Chell from the potato fair was something else.