Provost Baird tells the player that the research Kallichore cooperated with Tri-Tachyon on was explicitly forbidden by the Domain. This implies that Domain researchers already meddled in whatever field of hyperspace theory Tri-Tach messed with at alpha site,
before the Collapse. So, Domain researchers already had this explode in their face in the past (or had some warning that it
would explode). Then laws were implemented preventing related research.
Additionally, I remember that alpha site had an "artifact" they were basing their research off of (see description of Antimatter SRM Launcher...also, there might have been mention of it in the notebook from alpha site). What is this artifact? I think the answer influences the discussion of what caused the collapse:
- If it's human in origin, then that means the Domain (or independent groups/corporations) used this "forbidden" technology, against their own laws (human hubris/use of barely understood technology caused the Collapse).
- If it's alien/eldritch in origin, then maybe AI (probably rogue OMEGA-level AI, which I interpret as a kind of technological singularity) turned the Gates off to protect its own existence (which might imply that these aliens/eldritch entities were or were about to become a threat to said AI at the time of the Collapse...or perhaps the AI judged the possibility of the threat enough to turn off the Gates). This could imply an alien invasion of the Domain elsewhere.
- Alternatively, said eldritch beings/aliens are directly responsible for closing the Gates.
- If OMEGA-level AI-designed technology was the "artifact" discussed in the weapon description, the shenaniganry that killed alpha site is probably unrelated to the collapse.
- Or, finally, if said "artifact" was an intact OMEGA-level AI core, then the AI presumably killed everyone on alpha site before (or after, considering the state of Ziggurat when the player finds it) they could unleash some eldritch horror from hyperspace. Or cause the end of the universe with mad science shenanigans, etc.
- Once again, this possibility indicates AI may have closed the gates out of self preservation. Perhaps the Gate network was growing large enough to reach some "critical mass" the AI predicted, causing some apocalyptic effect (which researchers at alpha site were unknowingly very close to causing with their hyperspace experiments)?
So...what all these theories boil down to for me is that AI probably did it, humans (and their hubris) might have caused it, and there's an outlier chance the Gates were doomed from the start due to some inherent property of hyperspace.
Or maybe hyperspace just drives AI insane and this speculation tells me nothing about the collapse (though I consider this unlikely, considering the "song" that connects the Gates to alpha site/Ziggurat). Who knows?