In this tiny world they were provided with all the other necessities of life. None of the objects had manufacturing marks or brand logos—Trisolarans made them—but they looked exactly like human products.
Cheng Xin and Guan Yifan sometimes went into the fields to work alongside the robots. Sometimes they strolled about the universe—as long as they were careful not to leave footprints, they could keep on walking indefinitely and experience the feeling of traversing countless worlds.
They spent most of their time in front of the computer, however. It was possible to invoke a terminal from anywhere in the small universe, but they didn’t know where the CPU for the computer was located. The computer had a massive databank of text, image, and video from the Earth, most of which dated from before the Broadcast Era. The Trisolarans had clearly gathered the info as they studied humanity, and the material covered every field in the sciences and the humanities.
But even more information existed in the databank written in the Trisolaran language. This massive ocean of data was what interested them the most. Since they couldn’t find any software on the computer for translating Trisolaran writing into human languages, they had to study the Trisolaran script itself. Sophon acted as their teacher, but they soon discovered that this was an extremely difficult endeavor because Trisolaran writing was purely ideographic; unlike human scripts, which were mostly phonetic, Trisolaran writing had no connection to their speech, but expressed ideas directly. In the distant past, humans had also used ideographic scripts—such as some hieroglyphs—but most of these later disappeared.{
They began to read the Trisolaran material in the databank—at first haltingly, and then faster. They had two initial goals in mind: First, they wanted to know how the Trisolarans had recorded the period of history between their civilization and Earth civilization. Second, they wanted to know how this mini-universe was constructed. For the latter, they understood that they would likely not achieve a specialist’s level of understanding, but they wanted to at least understand it at the level of popular science. Sophon estimated that in order to achieve these two goals, they would need to spend one year to learn how to read Trisolaran better, then take another year to read in depth.
The fundamental principles underlying the small artificial universe seemed unimaginable to them; even the most basic mysteries puzzled them for the longest time. For instance, how could a complete ecological cycle function in a sealed space of only one cubit kilometer? What was the sun? What was its energy source? And most confounding: As a completely sealed system, where did the heat of the mini-universe go?
They asked Sophon these questions. Some she could answer; for others, she referred them to materials in the computer.
They also cared about the answer to one question in particular: Could the mini-universe communicate with the great universe? Sophon told them that there was no way for the mini-universe to transmit any information to the greater universe, but it was possible for the mini-universe to receive broadcasts from the great universe. She explained that all the universes were bubbles above a supermembrane—this was a fundamental conceptual image from Trisolaran physics and cosmology, and she could explain it no further. The great universe had enough energy to propagate information across the supermembrane. However, this was difficult and required a great expenditure of energy—the great universe would have to convert a Milky Way’s worth of matter into pure energy. As a matter of fact, the monitoring systems in Universe 647 often received messages from other great universes on the supermembrane. Some were natural phenomena; some were messages from intelligent beings that could not be decoded—but they had never received any message from the particular great universe they had come from.