The Three-Body Problem

Wang logs on to Three Body again. This time, the great palace is an Egyptian pyramid, but when he notices two soldiers dueling, they are in Western garb; the game’s version of the East has combined with its version of the West. When another man interrupts the fighting soldiers, he learns that the duelers are actually Isaac Newton and Gottfried Leibniz, and they are fighting over who invented calculus. Newton predicts that with the invention of calculus, it will be easy to solve the three-body problem—but the third man, who introduces himself as Von Neumann, is not so sure.

Wang explains that a computer will help them solve the equation, but Newton has never heard of such a thing. Instead, Von Neumann suggests that they can perform the complicated calculations necessary to solve the three-body problem using human beings. As he talks, Wang realizes that Von Neumann is another real player in the game, not a computer-generated character. Von Neumann and Newton want to present their idea to Qin Shi Huang, Emperor of the Qin Dynasty.

When the three men enter the palace, they are greeted by Qin Shi Huang, who has the “same eyes” as King Zhou and Pope Gregory. Qin tells the men to ask for help from Europe, as Europe and China are at war and right now, and “the wisdom of Westerners is terrifying.” Qin has given up on conquering Europe, but Von Neumann—whom Wong has deduced is Chinese—suggests that understanding the three-body problem is more powerful than winning any war ever could be. 

Von Neumann asks for three soldiers to demonstrate his idea for a human computer. When Qin offers to give 3,000 soldiers, Von Neumann pushes back; he believes that the East is falling behind in science because it has not realized that “even the most complicated objects of the universe are made from the simplest elements.” Finally, Von Neumann gets three soldiers and labels them “Input 1,” “Input 2,” and “Output.” He gives them each a white flag and a black flag.

Von Neumann teaches the soldiers how to act like a computer: depending on what color flags each of the Input soldiers holds up, the Output soldier will hold up a different flag. Using this system, Von Neumann has the three soldiers create all the different possible “gates” in computer science. He explains that with millions of soldiers, they can string these gates together to compute very complicated equations in minimal time. Once Von Neumann’s idea is accepted, the passage of time in the game speeds up, and a giant square of soldiers is assembled. While there are millions of people, they do not take up very much space. Wang realizes that “though it was powerful, the phalanx also revealed the fragility of civilization.”

Qin Shi Huang gives the order (“Computer Formation”), and the soldiers get into formation—they have effectively formed a giant motherboard. Von Neumann and Wang explain all the different parts of a computer operating system to Qin, and they tell Qin how these parts can be recreated in soldier form. They call the operating system “Qin 1.0.”

The time has come to test the machine. The black and white flags wave and surge as each input is transformed into an output. At one point, however, the surge stops; there has been some confusion. To the horror of Wang and Von Neumann, Qin orders all of the people in the area where the human computer stopped to be executed.

After a successful test, Newton asks the massive collection of people to run the three-body problem. As the flags wave and flip, Qin reflects on the Western criticism that the East suppresses creativity. He argues that “a large number of men yoked by severe discipline can also produce great wisdom when bound together as one.” Before Qin leaves, he reminds the men that no good fate awaits them if their experiment fails.

The game time speeds up again, and for 16 months, the human computer performs calculations. Finally, the computer spits out a prediction that a year-long Stable Era is about to begin. This time, though, there is no one for Qin to rehydrate, as all of the people and resources in the empire have been spent making this one computer. Yet rather than despair, Qin celebrates—just as Newton predicted, the sun begins to rise, heralding the return of a Stable Era.

Unfortunately, Qin’s joy does not last long. His astronomy minister informs him that an extremely rare tri-solar syzygy is approaching, in which all three of the suns are in a straight line. The feeling of gravity begins to diminish, and everything starts to float and come apart.

The people and things on the game planet begin to rise so far that they leave the atmosphere, and each person becomes an amorphous blob. Wang notices that the three suns are stacked together, like a “bright eye in the universe.” The game ends, and the message informs Wang that “Civilization Number 184 was destroyed by the stacked gravitational attractions of a tri-solar syzygy,” but that because of the invention of calculus and the computer, this society was able to begin solving the three-body problem. Wang logs off.

Seconds later, Wang gets a call from a stranger who explains that he is an administrator of the game. He asks Wang for his age, education, and employer, and tells Wang that if he refuses to give out this info, he will be permanently shut out of the game. Though the stranger will not answer any of Wang’s questions, he does invite Wang to a meet-up for players of the game on the following evening.