The Three-Body Problem

“Yes. There are dozens of other mathematical models. Of those, more than half are more advanced than yours. They’ve all been implemented and run on computers. During the past two centuries, such massive computation became the principal activity of this world. Everyone waited for the results as if waiting for Judgment Day.”

“And?”

“We have definitively proven that the three-body problem has no solution.”

Wang gazed up at the massive pendulum overhead. In the dawn light, it was crystal bright. Its deformed mirrorlike surface reflected everything around it like the eye of the world. In this place, in a distant age separated from the here and now by many civilizations, he and King Wen had passed through a forest of giant pendulums on their way to the palace of King Zhou. Just like that, history had made a long circuit and returned to its starting place.

The science advisor said, “It’s just like we guessed long ago: The three-body system is a chaotic system. Tiny perturbations can be endlessly amplified. Its patterns of movement essentially cannot be mathematically predicted.”

Wang felt his scientific knowledge and system of thought become a blur in a single moment. In their place was unprecedented confusion. “If even an extremely simple arrangement like the three-body system is unpredictable chaos, how can we have any faith in discovering the laws of the complicated universe?”

“God is a shameless old gambler. He has abandoned us!” The speaker was Einstein, waving his violin. Wang didn’t know when he had shown up.

The secretary general slowly nodded. “Yes, God is a gambler. The only hope for Trisolaran civilization is to gamble as well.”

By now, the giant moon was rising again from the dark side of the horizon. Its large, silvery image was reflected by the surface of the pendulum weight. The light wriggled strangely, as though the weight and the moon had developed a mysterious sympathy together.

“This civilization seems to have developed to a very advanced state,” Wang said.

“Yes. We’ve mastered the energy of the atom and reached the Information Age.” The secretary general didn’t seem to be too impressed by his own words.

“Then there is hope: Even if it’s impossible to know the pattern of the suns’ movements, civilization can continue to develop until it reaches a stage where it can survive the Chaotic Eras by protecting itself against the devastating catastrophes of those eras.”

“People once thought as you do. That was one of the motivating forces pushing Trisolaran civilization to tenaciously come back again and again. But the moon made us realize the naïveté of such an idea.” The secretary general pointed to the rising giant moon. “This is probably the first time you’ve seen this moon. Actually, since it’s about a quarter of the size of our planet, it’s no longer a moon, but a companion to our world in a double planet system. It resulted from the great rip.”

“The great rip?”

“The disaster that destroyed the last civilization. Compared to the civilizations before it, they had ample warning of the disaster. Based on surviving records, the astronomers of Civilization 191 detected a frozen flying star early on.”

Wang’s heart clenched as he heard the last phrase. A frozen flying star was a terrible omen for Trisolaris. When a flying star, or a distant sun, seems to come to a complete stop against the background starfield, then the sun’s and the planet’s motion vectors are aligned. This has three possible interpretations: the sun and the planet are moving in the same direction at the same speed; the sun and the planet are moving apart from each other; and the sun and the planet are moving toward each other. Before Civilization 191, this last possibility was purely theoretical, a disaster that had never occurred. But the population’s fear of it and their vigilance did not diminish, so much so that “frozen flying star” became an extremely unlucky phrase in many Trisolaran civilizations. A single flying star remaining still was sufficient to terrify everyone.