Greetings from Proxima Centauri

At the age of twenty-four, Zhang Beihai was selected into the "Spark Project". Mission codename: Kuafu. Destination: 4.3 Light years away. Return ticket: zero. The news spread and the whole city was excited. Only she asked in the corner of the cafeteria: "Then who will accompany you to dinner?" He was silent for a long time, and finally wrote her a virtual IOU - this coupon can be exchanged for Zhang Beihai's dinner treat, and the validity period is light years away. She put this string of codes into her mobile phone and changed the note to: Wait for someone who won't come back. On the day the "Kuafu" took off, she stood outside the launch site all night. I'm not watching the Rockets, I'm waiting for the redemption date of that IOU, which slowly becomes: forever.