Spacetime Bulletin

Biodata

Mechanism and Limits

Transmission

• A phone sends the message near a transformer distribution box while the Film Club’s Positron Cannon is aimed at the box and activated. The resulting Spacetime Black Hole captures the message’s radio waves, carrying them into the past, where a signal tower relays them to the recipient’s phone 6 9 15.
• The transmission window lasts 0.7 seconds. After overloading, the Positron Cannon must remain powered off for 20 hours before reuse 9 15.
• A successful transmission changes the course of history and causes a Spacetime Shift, or Worldline Jump. Jiang Ran alone detects the shift and retains memories of the previous history 9 14 15.
• Changing the sender or phone does not prevent transmission: Cheng Mengxue successfully sends a bulletin using her own phone 16.

Range and Rules

• The group initially sends bulletins three days into the past. Qin Feng later builds a control panel that lets them select earlier time nodes 15 25.
• The group’s revised user manual lists a 70-Chinese-character maximum and recommends early-morning experiments, when the power-grid load is low 29.
• Their usage guidelines voluntarily restrict messages to 30 days into the past because longer spans risk a less controllable butterfly effect. The guidelines also require unanimous agreement on the content, all three members’ presence, and secrecy 26 29.

History

• First transmission: Jiang Ran texts Cheng Mengxue’s lost phone on March 17; the message arrives on March 14. Its contents lead her to watch her phone more carefully, preventing the loss. After the resulting shift, she and Qin Feng do not remember the original incident 3 5.
• Controlled test: After repairing the Positron Cannon, the trio sends a test bulletin three days into the past. Cheng Mengxue’s phone receives both the intended message and an unexplained second bulletin containing numbers 9 15.
• Rescue of Xu Yan: The trio sends their past selves advance warning of Xu Yan’s drowning. The altered history saves her, though Jiang Ran awakens in a hospital after the shift 13 14.
• Later uses: The trio uses bulletins to win lottery prizes, help Cheng Mengxue pass a calculus makeup exam, and prevent the accident that critically injured Jiang Ran’s mother 16 25 27.
• Long-range consequences: A message sent ten years into the past to save Qin Feng’s father produces a worldline in which Cheng Mengxue has died and the friends’ lives have diverged 39.

Unexplained Bulletin

• The extra bulletin received during the controlled test bears the number string 289269426494642. Jiang Ran fears it may be a warning, but its sender is unknown 9 10 33.
• The trio connects the numbers to nine-palace-grid input and interprets the text as “Don’t trust it.” They cannot establish what—or whom—the warning concerns, and no follow-up message arrives 23 24 33.