Sophon did not answer for a long time. Again, she sat still, pondering with her eyes lowered. Cheng Xin felt time flow more slowly than ever. With every passing second, her hope diminished, and she was certain that Sophon’s answer was going to be
“Yes.”
“How?” Cheng Xin couldn’t help herself.
Sophon looked away from Luo Ji, shook her head, and refilled their tea bowls. “I can tell you nothing more. Really. I can never tell you anything again.”
The Conversation of the Way of Tea gave the tiniest bit of hope for the expectant mass of humanity: It was possible to broadcast a safety notice to the cosmos to avoid dark forest strikes.
After the conversation between Sophon, Cheng Xin, and Luo Ji was publicized, everyone began to ponder the problem of how to broadcast a safety notice. Countless proposals flooded in, sent by sources as august as the World Academy of Sciences and as humble as elementary schools. It was perhaps the first time in the history of humanity that the entire species focused their mental energy on the same practical problem.
The more they thought about it, the more the safety notice turned into a riddle.
All the proposals could be divided into two broad categories: the declaratory camp and the self-mutilation camp.
The declaratory camp’s basic conception, as can be intuited from the name, was a broadcast to the universe proclaiming the harmlessness of Earth civilization. Their main efforts were directed at how to express such a message. But in the eyes of most, their premise seemed foolish. No matter how well crafted the message, who in this heartless universe would believe it? The fundamental requirement for a safety notice was that the countless civilizations in the universe would trust it.
The self-mutilation camp represented the majority view. They theorized that the safety notice had to represent the truth, which implied that the notice required both “talking” and “doing.” And of the two, “doing” was the key. Humanity had to pay a price for living in the dark forest and transform Earth civilization into a truly safe civilization—in other words, Earth civilization had to mutilate itself to eliminate its potential to threaten others.
Most of the self-mutilation plans focused on technology and advocated humanity to retreat from the space age and the information age and found a low-technology society—perhaps a society reliant on electricity and the internal combustion engine, such as at the end of the nineteenth century, or even an agrarian society. Considering the rapid decline in global population, these plans were feasible. In that case, the safety notice would be nothing more than an announcement that the Earth possessed a low level of technology.
More extreme ideas emerging from the self-mutilation camp proposed intellectual disablement. Using drugs or other neuromanipulation techniques, humans could lower their own intelligence. Moreover, such lowered intelligence could be fixed via genetic manipulation in future generations. As a result, a low-technology society would result naturally. Most people were revolted by the notion, but it remained in wide circulation. According to the proponents, the safety notice was equivalent to public disclosure of humanity’s low intelligence.
There were other ideas as well. For instance, the self-deterrence camp advocated building a system that, once activated, would be beyond human control. The system would monitor humanity for any behavior incongruent with its self-proclaimed safe nature and initiate the destruction of the world upon detection.
This was a feast for the imagination. Countless plans competed for attention: some subtle, some strange, yet others as sinister and terrifying as cults.
But none of these plans captured the essence of the safety notice.
As Sophon pointed out, a key characteristic of dark forest strikes was their casual nature. The attacker did not bother to conduct close-range surveillance of the target. All these plans engaged in performance art with no audience. No matter how faithful the act, no one would see it except the performer. Even under the most optimistic conditions—suppose some civilizations, like doting parents, cared to observe Earth civilization up close, perhaps even devoting long-term monitoring equipment to the Solar System similar to the sophons, they would still make up only a minuscule portion of the large number of civilizations in the universe. In the eyes of the vast majority of civilizations, the sun was but a dim dot many, many light-years away, showing no distinguishing details at all. This was the fundamental mathematical reality of the cosmic dark forest.
