Love Letter

Everyone thought Shanghai was a little arrogant, but he was very good at telling stories, so the important task of educating the younger generation usually fell to him.

Yixing was one of the more sensible youngsters, and he was eager to learn. Suzhou, Hangzhou, and Wuxi begged Shanghai to tell him some history. Shanghai thought it over for several days and reluctantly agreed. The moment the connection went through, Yixing sent over a string of questions. There was so much information that the G50 Expressway suffered a rarely seen traffic jam.

Jiaxing had to pause his thinking and open the S12 Expressway as a backup channel for them. Even so, it took a full three days to get the thoughts on both sides sorted out.

Shanghai said, “Don’t ask questions yet. Let me tell you the history.”

Jiaxing said, “Then you’ll have to start from the beginning.”

Shanghai said angrily, “At the speed cars travel now, I couldn’t finish even in two years! Let’s just start with the planner’s story. No interrupting. Listen carefully.”

The story began with a planner at the Shenzhen Municipal Transport Commission. It would be inconvenient to mention his name, so let us call him “A.”

A-jun had a bachelor’s degree in computer science and a master’s in urban planning. A few years after passing the civil service exam, he was entrusted with an important task: transportation planning for Shenzhen’s Qianhai New District. He counted as one of the elite of his generation, but he had an even more admirable long-distance girlfriend. She did physical chemistry research full-time in Beijing, and her project involved experiments in a microgravity environment. By a stroke of luck, she became an astronaut on the ISS, the International Space Station, and would spend seven months in space.

Translator’s note: Jun (君) is a polite, slightly literary suffix, roughly “Mr.” It’s the narrator being courteous to someone he won’t name.

While his girlfriend trained at the astronaut training center in Beijing, A-jun was also busy with work. Only when the Soyuz rocket lifted off did the two of them realize with a start that they hadn’t even had time to say goodbye or wish each other well. The spacecraft docked successfully with the station, and his girlfriend began her journey in space. A-jun waited miserably in his little corner of Shenzhen, clinging to their video call once every five days, unable to ease his longing.

All A-jun could do was throw himself into work, keeping company with traffic lights all day long. One day, after work, he returned to his high-rise apartment and looked down at the bustling traffic on the roads below. A wild idea suddenly struck him: how much the endless stream of cars on the road resembled the punched paper tape used by old computers. Computers in the 1930s and ’40s used punched paper tape as their input and output device. A hole in the tape represented 1, no hole represented 0, and in this way data was turned into binary code. If a spot on the road with a car was 1, and a spot without a car was 0, couldn’t that also transmit binary information?

A-jun began designing the traffic light system for Qianhai New District. He used the light signals at single intersections to form the most basic NOT gates, NAND gates, and XOR gates. City blocks made up adders, flip-flops, and memory, and the vehicles driving on the roads served as binary data streams, turning the whole district into a simple computer system. Its output was an endlessly extending strip of punched paper tape: the traffic on the S13 Expressway.

He used the S13 Expressway to send a love letter to his girlfriend in space. The International Space Station circled Earth 15.79 times a day, so his girlfriend passed over Shenzhen 15.79 times a day, and each time she had at least three minutes in which she could observe the Shenzhen toll station on the S13 Expressway. The traffic on the S13 never stopped. Day and night, night and day, the message repeated without end. Day after day, month after month, the love letter played over and over again. For A-jun, a science guy through and through, this was the ultimate romance.

“Did his girlfriend see those messages?” Jiaxing asked.

Shanghai said, “No interrupting. What happened next, you might already know.”

The story of A-jun and his girlfriend has no ending, because the history of an individual human is too insignificant, and too brief. But the history of urban intelligence began there. The embryonic computer in Qianhai New District slipped out of A-jun’s control and reproduced on its own, gradually growing into a giant computer the size of a city, and eventually giving birth to intelligence.

After Shenzhen awakened, he sent traffic messages to other cities, setting off a wave of urban evolution around the globe. Today, most cities of medium size and up have intelligence. As long as the roads are clear and there are enough vehicles, they can communicate with one another and grow together. Supercities like Beijing, Shanghai, Hong Kong, and Tokyo are already highly developed life-forms, able to ponder the ultimate questions of life, the universe, and time.

Only Shenzhen, the very first to sprout intelligence, has made no progress. He has nothing but the most basic ability to think.

Jiaxing asked, “Is Shenzhen still kind of dumb now?”

Shanghai sneered. “Who says he isn’t? If I send him a slightly longer message along the G35, his language gets all jumbled and he can’t reply. And this is our ancestor. So embarrassing I can’t stand it!”

Translator’s note: Shanghai slips into Shanghainese for that last bit (“our ancestor,” “can’t stand it”). Very much the local.

Jiaxing asked, “But what did that love letter actually say?”

Shanghai said, “A simple brain like that, what could it write? The shameful part is that, to this day, it’s still playing nonstop.”

To this day, the vehicles driving on the S13 Expressway have no idea that, day and night, day after day, they are still piecing together a message that is broadcast over and over.

To this day, Shenzhen still foolishly recites:

Come to Shenzhen, marry me.

Come to Shenzhen, marry me.

Come to Shenzhen, marry me.