Ernest Littlefields's Library
Humans have occasional access to ZPMs. Asgard have access to.... something, it works, whatever the exact process is, I never saw it discussed indepth on the show, but have seen people argue over it as if they knew. What we can infer comes from the show is how fast ZPMs vs Asgard tech gets you. The Asgard can zip between galaxies much faster than humans can as of the end of Stargate Atlantis, minus the wormhole drive. Asgard clearly lack that, had they had it, replicators wouldn't of been a threat.
All four species of the ancient alliance could write linear languages, as we can see from the Ernest episode. Humans have no issue talking to the Ancients, Asgard and Nox, so if there was a mere linguistic hurdle, requiring a language based on pure atomic chemistry just to communicate, it would seem logical the Furlings have a bizarre cognition that the rest of the races couldn't track with and easily comprehend requiring such a rudimentry, universal language- but we see a example of the Furling script and know it isn't likely the case, they write in something akin to a alphabetic script. They are unlikely to be any incomprehensible than the other three.
So I am guessing Ernest's notes consist of engineering data from the Atom to the Molecule the four great races shared, and likely wasn't purely military tech, as the Nox are currently in our era pacifists (perhaps not then but definately now, and I will presume then as Asgard are only 100,000 years old as a civilization). I don't know if we can say it was all purely military info they shared on how to build stuff or understand how stuff worked, but the presence of the Nox suggests otherwise. Lets assume it is generic engineering data on shared standards on getting around fast. You need that in a grand alliance, even the Nox would agree.
I think they were sharing concepts like more efficient hyperdrive travel, defensive shields, etc. People sometimes argue Asgard batteries/energy production is better than ancient ZPMs. I doubt it. Yes, they move quicker than human ships using ZPMs, but a human ship with a ZPM is like a trireme with a nuclear reactor. Can you automate the oars with unlimited nuclear energy.... yes, but anyone knowing about propellers wouldn't bother. This is the Ancients communicating to everyone your concepts each race figured out independently are nice and all, but here is a propeller. Yes, Ancients have flying carpets, but lets master the propeller here and agree it is the minimum of our alliance.
I'm thinking this might be when ideas like the Kiron was first discussed between them. Take atoms, then set up weird chemical processes, and explain step by step the odd process.... and you get a new engineering concept for more efficient energy release, or how to transfer it without loss, etc.
A Ancient ZPM can cause the Atlantis City Ship to jump between Galaxies, so it isn't under powered vs Asgard tech. I think we see in this library how the Asgard gained their concepts of using what they had to move faster. This likely gave the Nox the ability to float and cloak a city- no mean feat. That is a energy hog as much as the Asgard zipping between galaxies or deconstructing a ship.
This was likely less a place for philosophical discussion and more a acceptance that the debates in hypothetical physics between different races wasn't translating in any meaningful sense in their translations of one another's mathematical and physical works. Each race's math was too wacky, unstabke, built on conflicting opinions. They had to get their best thinkers together and literally start with the basics. If the Nox were involved, it probably wasn't purely fixated on weapons, not a NATO alliance. Asgard perhaos saw it that way, not the Nox (again, assuming they were pacifist then). The idea of a alliance was having joint capability to show up and do something together. Like if a inhabited world's star started to go supernova.... wildly different capacities and inefficiencies would throw off cooperation. The Nox took in Tollan refugees, so they would likely agree to a humanitarian alliance, where shared tech and mutual deoendency would be essential.
Does a shared standard mean everyone had ZPMs? No.... it could just be the bottom line of what was acceptable in a joint alliance. You might have the Asgard equivelent of Samatha Carter back then knowing her chemistry, with a Ancient trying to show holographically a Kiron- a idea the Asgard never would of considered before, with the "A-ha moment" taking place thousands of years ago. Ernest jotted down the notes of these examples, but lacked the dialogue or engineering frame of reference. He just knew the physics of his day, and saw visualizations of stuff turning incomorehensible because he isn't standing there with a Ancient giving him feedback during a lecture. He doesn't even know the topic being discussed.
But it doesn't mean this library unlocked all the Ancients more advanced concepts. Asgard were still mining a Ancient database for new concepts. Everyone except the Ancients likely walked away mind racing with grand new ideas that swallowed their intellectuals up for generations. Ancients loved the ZPMs, they likely would of had to sit in this chemistry auditorium teaching everyone new earth shattering concepts daily in order for them to catch up to the Ancients.
Good news is, Ancients liked using crystals. The library toppled in the ocean but is likely recoverable- it was by the shore afterall. Plus they have the Asgard database to reconstuct the Asgard takeaway from these conversations. It would make sense for the Asgard to reference this era as it likely is the frame of reference they had in their own history for making a database holographic interactic library to give to humanity. They learned that way, in that very spot. Humans too can learn this way.
Now a bit more speculation. We don't know the frame of reference for how old this library could be, other than younger than 100,000 years given the age of Asgard civilization. Assuming the Asgard didn't show up in buttflaps and spears, probably wasn't the first 10,000 of it. When was this library built?
Very old, brick cities in the milky way didn't survive very well intact. Daniel Jackson being a archeologist can attest to this fact. They like to build in brick. But we have Atlantis and outposts with ZPM tech intergrated suggesting otherwise- they could build to last, but usually didn't. Stuff is usually in ruins, and we find this library on the cliff in ruins.
So we have a 90,000 year old alliance in timeframe. Could it be a alliance from after the evacuation of Atlantis? Yeah. Where the Furlings at, if that is the case.... they didn't seem to much benifit and stick around. Asgard seemed involved. Nox wers present, still around. Everyone would of recognized the ancients os omnipowerful, yet also a critically endangered species.... so this could be the last grand strategy of the Ancients at galactic or intergalactic statecraft. After that it was just a few ascending or doing Camelot- pet projects. Nox seem rather unimpressed. Asgard seem with the program. Furkings extinct or moved on, or are really good with hiding.
If older than the Wraith War, then it is a late stage Atlantean position on Statecraft. They lived in a neighboring galaxy, still had interests in the Milky Way. Still open to diplomacy. We know Earth was special to them (Asgard seemed to follow favkring humans for whatever reason- I personally think Janus made them a offer they couldn't refuse but it could just as well he this alliance). But that would be a theory of managing a distant alliance in another galaxy, how they ran Pegasus and dealt with the Wraith.... doesn't seem like the Nox or Asgard much cared. The Wraith War may of ended the alliance, or it might of died out long beforehand. Or it may of only begun as a reponse to losing it. I don't think we will be able to precisely figure this stuff out till a new TV series air and gives us more of a data dump.