Event Description
In the century-plus following the Great Trough, human society underwent an astonishing technological leap. Although fundamental physics was locked by Sophons at early 21st-century levels, preventing breakthroughs in particle physics, quantum mechanics, and other frontier fields, humanity made dramatic advances in applied technology within existing theoretical frameworks.
The achievement of controlled nuclear fusion completely solved the energy crisis, providing inexhaustible power for space development. The completion of space elevators drastically reduced surface-to-orbit transportation costs, making large-scale space industry possible. On this foundation, humanity began constructing stellar-class warships — enormous military vessels capable of interstellar travel. After over a century of construction, humanity's Space Force possessed nearly two thousand stellar-class ships, forming what appeared to be a formidable interstellar military force.
Simultaneously, Earth society itself underwent profound transformation. Large-scale underground city construction, widespread artificial intelligence adoption, and social restructuring gave human civilization a radically different face from the 21st century.
The Trap of Optimism
The rapid technological progress gave humanity a dangerous illusion — they began to believe they had developed the strength to confront Trisolaran civilization. When the Trisolaran probe (the Droplet) approached the Solar System, the Space Force greeted it not with defense and vigilance but with an almost carnival-like "welcoming" attitude. Many even regarded the Droplet as a peaceful envoy sent by the Trisolarans to negotiate.
"Weakness and ignorance are not barriers to survival, but arrogance is." — This quote perfectly encapsulates the era. Humanity forgot that their fundamental science had been locked, forgot that their adversary possessed technology far beyond their own, and forgot that good intentions don't exist in the dark forest. The devastating defeat of the Doomsday Battle shattered this arrogance completely.
Historical Legacy
Although this period ultimately ended with the Doomsday Battle disaster, the achievements of the technological explosion era did not entirely vanish. The fleeing fleet used exactly these warships to escape the Solar System, carrying the seeds of human civilization onward. The accumulated space technology also laid the foundation for the later Deterrence Era and Bunker Project.