Snowflakes drifted quietly outside.
Yuan Su leaned by the window, the hallway's overhead light casting a faint shadow beneath his brow.
"Song Jinnian."
He spoke suddenly, his voice low. "After taking such a long detour, this was what you wanted to talk about all along, wasn't it?"
Standing a couple of steps away, Song Jinnian smiled. He made no attempt to hide it, openly breathing out a cloud of white vapor instead.
"Yes. Even without all this crap with Yuan Hongzheng, I was planning to come find you in Rinzhou after the New Year."
He kept both hands in his coat pockets, his expression unusually serious.
"I want you to work on a project with me."
Yuan Su lifted his eyes, his gaze unreadable. "What kind of project?"
"Automated sorting for logistics." Song Jinnian looked at him. "You know how popular online shopping is now. There'll only be more parcels in the future. Getting machines to move them faster and more accurately is a major problem."
"Logistics?" he asked. "That's coding work. Why come to me?"
"Code is the skin. Physics is the bones."
Song Jinnian's voice was quiet but clear. "Do you know what the biggest challenge is with automated machinery right now? It isn't that it can't calculate fast enough. It's that it isn't stable enough."
"When tens of thousands of parcels are moving along conveyor belts at high speed, how do you calculate friction so they don't pile up? How do you set their trajectories at bends so they don't collide? How do you get a robotic arm to accurately grab fragile items of different weights in a fraction of a second?"
Song Jinnian paused, then enunciated every word. "All of that takes an exceptional intuition for physics to build the models. And that's exactly where our