- Apparently the book describes them as aliens. A terrestrial advanced race is cool, true, but not the case here.
- It's pretty much stated in the movie also—there's a short conversation involving One Night where the NTIs are implied to be from space.
- They're referred to as "non-terrestrial" several times in the movie. Admittedly, the characters have no good reason to make this assumption, but it's not just something the fans made up.
- Maybe "terrestrial" in this case refers to land-dwelling species?
- For what it's worth, the (incredibly obscure) game pegs them as actual aliens.
I grew up in the final years of the Cold War, and so I understand the earnest, optimistic wish of this movie (and others in the genre) for some Benevolent Space Brothers to make us all get along - if necessary, by threatening us with annihilation unless we prove that Not All Humans Are Bastards. But take a look back from the safe side of The Great Politics Mess-Up, and some serious Fridge Horror sets in: humanity's fate is now in the hands of beings beyond our reach (both physically and in technology), who still might decide to wipe us all out, at any time, for any reason. (Maybe we're killing too many tuna.) Or perhaps just "cull" us back to a more manageable, less polluting, pre-industrial level, or demand annual tributes of children, or anything else they feel like... One thing this troper remembers very well from that era was the sense of helplessness, the faint fear always in the background that due to circumstances beyond one's control, the world might end today. The ending of "The Abyss" doesn't actually remove this Damoclean threat, it merely escalates it to the next level and takes the decision entirely out of our hands. Instead of human political and ideological rivals (whom we did, eventually, learn to get along with), we now have untouchable alien overlords. "God exists, and He's Atlantean." And if one includes the mental influence shown/implied in the novel, we might not even be allowed to think this is wrong. Water-nanites in our brains, keeping us docile and content... everyone lining up on the beaches, neat and orderly, for our divine masters' next culling...
- Considering the guy that made this has a pretty obvious case of Human Guilt, he probably does in fact think we'd all be better off with benevolent fascist aliens controlling our every move.
- I'm guessing whoever wrote the novelization had this same thought and decided to fix it, considering the Not So Different entry on the main page; all of this is extremely unlikely if what the aliens take away from the course of events is "in sitting in judgement of a less advanced race we are being petty and juvenile so we need to grow up as much as we're telling them to."
Kitch here, with a thought I've had in my brain for years about the drowning scene. Why didn't Bud start swimming the moment Lindsey was submerged? He waited to swim to Deep Core at least until she lost consciousness, and potentially longer (we don't know how long it was between his Big "NO!" and when he actually started swimming). That's a minimum of a minute (possibly more) that could've meant a more positive outcome to Lindsey's resuscitation, instead of ultimately needing a miracle. (The novelization says Lindsey really did die, and the aliens actually revived her based on their reaction to Bud's desperation to save her.)
- When you drown you can't control yourself, so she'd be kicking and lashing all the way through. Arguably, she could have involuntarily hurt herself (and thus bleeding out), or even damage Bud's diving gear.