The technology that a Level 5 Civilization had validated using black holes went without saying: the Negative Energy Extraction Device.
Humanity had long speculated that black holes were the refueling stations of Level 5 Civilizations. This was later confirmed by the Daya Civilization, but unfortunately, the Daya Civilization had not handed this technology over to humanity—or rather, humanity had been unwilling to buy it.
Because the Daya Civilization's original condition had been that humanity exchange Lyra's Materials Technology for it.
For one reason or another, the two sides had failed to reach an agreement. In the end, they simply could not trust each other.
But humanity was not discouraged. It would have been good to buy it, but if they could not, they would research it themselves. It was merely a branch technology under the force-field Technology Tree; human scientists believed it was only a matter of time.
Sure enough, after several centuries of effort, the theories involved in this technology gradually became clear, and it had now reached the validation stage.
A successful validation would mean that the relevant theories established by humanity were self-consistent and conformed to the laws of nature. After that, they could move from theory to experimental technological creation.
Come to think of it, none of humanity's technological achievements had been attained overnight. Every one of them required long periods of research and accumulation, even technologies that, according to predictions, all Level 5 Civilizations should possess.
The many difficulties encountered during the research process also told humanity that perhaps "all Level 5 Civilizations should possess it" did not mean every Level 5 Civilization could truly master it. It was merely a premise based on the Theory of Everything.
It was like how, in theory, every country on Earth had the ability to land on the